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class="vector-toc-numb">2</span> <span>Characteristics</span> </div> </a> <button aria-controls="toc-Characteristics-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Characteristics subsection</span> </button> <ul id="toc-Characteristics-sublist" class="vector-toc-list"> <li id="toc-Size_and_shape" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Size_and_shape"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Size and shape</span> </div> </a> <ul id="toc-Size_and_shape-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Rotation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Rotation"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Rotation</span> </div> </a> <ul id="toc-Rotation-sublist" class="vector-toc-list"> </ul> </li> <li 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aria-controls="toc-Observation-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Observation subsection</span> </button> <ul id="toc-Observation-sublist" class="vector-toc-list"> <li id="toc-Discovery" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Discovery"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Discovery</span> </div> </a> <ul id="toc-Discovery-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Observation_2" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Observation_2"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Observation</span> </div> </a> <ul id="toc-Observation_2-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Comet_chemistry" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Comet_chemistry"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Comet chemistry</span> </div> </a> <ul id="toc-Comet_chemistry-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Suspected_nucleus_fragmentation" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Suspected_nucleus_fragmentation"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>Suspected nucleus fragmentation</span> </div> </a> <ul id="toc-Suspected_nucleus_fragmentation-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Exploration" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Exploration"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Exploration</span> </div> </a> <ul id="toc-Exploration-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Notes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Notes"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Notes</span> </div> </a> <ul id="toc-Notes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet 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Available in 32 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-32" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">32 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Afrikaans" lang="af" hreflang="af" data-title="2I/Borisov" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/2%D8%A2%D9%8A/%D8%A8%D9%88%D8%B1%D9%8A%D8%B3%D9%88%D9%81" title="2آي/بوريسوف – Arabic" lang="ar" hreflang="ar" data-title="2آي/بوريسوف" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/2I/%D0%91%D0%BE%D1%80%D0%B8%D1%81%D0%BE%D0%B2" title="2I/Борисов – Bulgarian" lang="bg" hreflang="bg" data-title="2I/Борисов" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Bosnian" lang="bs" hreflang="bs" data-title="2I/Borisov" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Chuvash" lang="cv" hreflang="cv" data-title="2I/Borisov" data-language-autonym="Чӑвашла" data-language-local-name="Chuvash" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Czech" lang="cs" hreflang="cs" data-title="2I/Borisov" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Danish" lang="da" hreflang="da" data-title="2I/Borisov" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – German" lang="de" hreflang="de" data-title="2I/Borisov" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Spanish" lang="es" hreflang="es" data-title="2I/Borisov" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Basque" lang="eu" hreflang="eu" data-title="2I/Borisov" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/2I/Borissov" title="2I/Borissov – French" lang="fr" hreflang="fr" data-title="2I/Borissov" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/2I/%EB%B3%B4%EB%A6%AC%EC%86%8C%ED%94%84" title="2I/보리소프 – Korean" lang="ko" hreflang="ko" data-title="2I/보리소프" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Croatian" lang="hr" hreflang="hr" data-title="2I/Borisov" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Indonesian" lang="id" hreflang="id" data-title="2I/Borisov" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Italian" lang="it" hreflang="it" data-title="2I/Borisov" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A9%D7%91%D7%99%D7%98_%D7%91%D7%95%D7%A8%D7%99%D7%A1%D7%95%D7%91" title="שביט בוריסוב – Hebrew" lang="he" hreflang="he" data-title="שביט בוריסוב" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Latin" lang="la" hreflang="la" data-title="2I/Borisov" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Hungarian" lang="hu" hreflang="hu" data-title="2I/Borisov" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%B8%E0%B4%BF/2019_%E0%B4%95%E0%B5%8D%E0%B4%AF%E0%B5%824_(%E0%B4%AC%E0%B5%8B%E0%B4%B1%E0%B4%BF%E0%B4%B8%E0%B5%8B%E0%B4%B5%E0%B5%8D)" title="സി/2019 ക്യൂ4 (ബോറിസോവ്) – Malayalam" lang="ml" hreflang="ml" data-title="സി/2019 ക്യൂ4 (ബോറിസോവ്)" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Dutch" lang="nl" hreflang="nl" data-title="2I/Borisov" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%83%9C%E3%83%AA%E3%82%BD%E3%83%95%E5%BD%97%E6%98%9F_(2I/Borisov)" title="ボリソフ彗星 (2I/Borisov) – Japanese" lang="ja" hreflang="ja" data-title="ボリソフ彗星 (2I/Borisov)" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Polish" lang="pl" hreflang="pl" data-title="2I/Borisov" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Portuguese" lang="pt" hreflang="pt" data-title="2I/Borisov" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Romanian" lang="ro" hreflang="ro" data-title="2I/Borisov" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/2I/%D0%91%D0%BE%D1%80%D0%B8%D1%81%D0%BE%D0%B2%D0%B0" title="2I/Борисова – Russian" lang="ru" hreflang="ru" data-title="2I/Борисова" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Slovak" lang="sk" hreflang="sk" data-title="2I/Borisov" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Slovenian" lang="sl" hreflang="sl" data-title="2I/Borisov" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Swedish" lang="sv" hreflang="sv" data-title="2I/Borisov" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Turkish" lang="tr" hreflang="tr" data-title="2I/Borisov" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9C%D1%96%D0%B6%D0%B7%D0%BE%D1%80%D1%8F%D0%BD%D0%B0_%D0%BA%D0%BE%D0%BC%D0%B5%D1%82%D0%B0_%D0%91%D0%BE%D1%80%D0%B8%D1%81%D0%BE%D0%B2%D0%B0" title="Міжзоряна комета Борисова – Ukrainian" lang="uk" hreflang="uk" data-title="Міжзоряна комета Борисова" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/2I/Borisov" title="2I/Borisov – Vietnamese" lang="vi" hreflang="vi" data-title="2I/Borisov" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/2I/%E9%AE%91%E9%87%8C%E7%B4%A2%E5%A4%AB%E5%BD%97%E6%98%9F" title="2I/鮑里索夫彗星 – Chinese" lang="zh" hreflang="zh" data-title="2I/鮑里索夫彗星" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q67328765#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div 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.hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">"Comet Borisov" redirects here. For other comets discovered by Gennadiy Borisov, see <a href="/wiki/List_of_comets_discovered_by_Gennadiy_Borisov" title="List of comets discovered by Gennadiy Borisov">List of comets discovered by Gennadiy Borisov</a>.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox"><caption class="infobox-title">2I/Borisov</caption><tbody><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Comet-2IBorisov-HubbleST-20191016_(cropped).png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png/290px-Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png" decoding="async" width="290" height="217" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png/435px-Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/de/Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png/580px-Comet-2IBorisov-HubbleST-20191016_%28cropped%29.png 2x" data-file-width="803" data-file-height="602" /></a></span><div class="infobox-caption" style="line-height:1.2em;">Borisov in October 2019<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup></div></td></tr><tr><th colspan="2" class="infobox-header" style="background-color:#FFE0C2">Discovery</th></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/List_of_minor_planet_discoverers" title="List of minor planet discoverers">Discovered by</a></th><td class="infobox-data"><a href="/wiki/Gennadiy_Borisov" title="Gennadiy Borisov">Gennadiy Borisov</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/List_of_observatory_codes" title="List of observatory codes">Discovery site</a></th><td class="infobox-data"><a href="/wiki/List_of_observatory_codes#L51" title="List of observatory codes">MARGO observatory</a>, Nauchnyy, Crimea</td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Discovery date</th><td class="infobox-data">30 August 2019<br />Earliest <a href="/wiki/Precovery" title="Precovery">precovery</a>:<br />13 December 2018</td></tr><tr><th colspan="2" class="infobox-header" style="background-color:#FFE0C2"><a href="/wiki/Osculating_orbit" title="Osculating orbit">Orbital characteristics</a></th></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Epoch_(astronomy)" title="Epoch (astronomy)">Epoch</a></th><td class="infobox-data">5 January 2020<sup id="cite_ref-JPL-Data_4-0" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Observation_arc" title="Observation arc">Observation arc</a></th><td class="infobox-data">389 days</td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Number of<br />observations</th><td class="infobox-data">1191</td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Apsis" title="Apsis">Perihelion</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7011300186079304034♠"></span>2.006<span style="margin-left:.25em;">62</span><span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.000<span style="margin-left:.25em;">02</span> <a href="/wiki/Astronomical_unit" title="Astronomical unit">AU</a></span></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Semi-major_axis" class="mw-redirect" title="Semi-major axis">Semi-major axis</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="2988872644340715676♠"></span>−0.851<span style="margin-left:.25em;">32</span><span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.000<span style="margin-left:.25em;">07</span> AU</span><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>b<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Orbital_eccentricity" title="Orbital eccentricity">Eccentricity</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7000335700000000000♠"></span>3.3570<span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.0002</span> (JPL)<br /><span class="nowrap"><span data-sort-value="7000335700000000000♠"></span>3.357</span> (MPC)<sup id="cite_ref-MPC-DB_6-0" class="reference"><a href="#cite_note-MPC-DB-6"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Orbital_inclination" title="Orbital inclination">Inclination</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="6999768878622027323♠"></span>44.0535°<span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.0001°</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/Longitude_of_the_ascending_node" title="Longitude of the ascending node">Longitude of<br />ascending node</a></div></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7000537823209002053♠"></span>308.1500°<span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.0003°</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Argument_of_periapsis" title="Argument of periapsis">Argument of<br />periapsis</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7000364990932625763♠"></span>209.1244°<span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.0004°</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Last perihelion</th><td class="infobox-data">8 December 2019<sup id="cite_ref-JPL-Data_4-1" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-MPC-DB_6-1" class="reference"><a href="#cite_note-MPC-DB-6"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Gray234_7-0" class="reference"><a href="#cite_note-Gray234-7"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Next perihelion</th><td class="infobox-data"><i>interstellar object</i></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Earth <a href="/wiki/Minimum_orbit_intersection_distance" title="Minimum orbit intersection distance">MOID</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7011163513464632514♠"></span>1.093<span style="margin-left:.25em;">02</span> AU</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;">Jupiter <a href="/wiki/Minimum_orbit_intersection_distance" title="Minimum orbit intersection distance">MOID</a></th><td class="infobox-data"><span class="nowrap"><span data-sort-value="7011357239715231600♠"></span>2.388 AU</span></td></tr><tr><th colspan="2" class="infobox-header" style="background-color:#FFE0C2"><span class="anchor" id="Infobox_Physical_characteristics"></span> Physical characteristics</th></tr><tr><th scope="row" class="infobox-label" style="white-space:nowrap;line-height:1.2em;"><a href="/wiki/Comet_nucleus" title="Comet nucleus">Dimensions</a></th><td class="infobox-data">≤ 0.5 km<sup id="cite_ref-Jewitt2019b_8-0" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup>(for an <a href="/wiki/Albedo" title="Albedo">albedo</a> of 0.04)<br />≤ 0.4 km<sup id="cite_ref-Hui2020_9-0" class="reference"><a href="#cite_note-Hui2020-9"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup></td></tr></tbody></table> <p><b>2I/Borisov</b>, originally designated <b>C/2019 Q4 (Borisov)</b>,<sup id="cite_ref-MPEC2019-S72_10-0" class="reference"><a href="#cite_note-MPEC2019-S72-10"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> is the first observed <a href="/wiki/Rogue_comet" class="mw-redirect" title="Rogue comet">rogue comet</a> and the second observed interstellar interloper after <a href="/wiki/%CA%BBOumuamua" title="ʻOumuamua">ʻOumuamua</a>.<sup id="cite_ref-EA-20191014_11-0" class="reference"><a href="#cite_note-EA-20191014-11"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Grossman2019_12-0" class="reference"><a href="#cite_note-Grossman2019-12"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> It was discovered by the <a href="/wiki/Crimean" class="mw-redirect" title="Crimean">Crimean</a> <a href="/wiki/Amateur_astronomy" title="Amateur astronomy">amateur astronomer</a> and telescope maker <a href="/wiki/Gennadiy_Borisov" title="Gennadiy Borisov">Gennadiy Borisov</a> on 29 August 2019 <a href="/wiki/UTC" class="mw-redirect" title="UTC">UTC</a> (30 August <a href="/wiki/Moscow_Time" title="Moscow Time">local time</a>).<sup id="cite_ref-NYT-20191207a_13-0" class="reference"><a href="#cite_note-NYT-20191207a-13"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-RIANovosti_14-0" class="reference"><a href="#cite_note-RIANovosti-14"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> </p><p>2I/Borisov has a <a href="/wiki/Heliocentric" class="mw-redirect" title="Heliocentric">heliocentric</a> <a href="/wiki/Orbital_eccentricity" title="Orbital eccentricity">orbital eccentricity</a> of 3.36 and is not bound to the Sun.<sup id="cite_ref-NYT-20191224_15-0" class="reference"><a href="#cite_note-NYT-20191224-15"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> The comet passed through the <a href="/wiki/Ecliptic" title="Ecliptic">ecliptic</a> of the Solar System at the end of October 2019, and made its closest approach to the Sun at just over <span class="nowrap"><span data-sort-value="7011299195741400000♠"></span>2 <a href="/wiki/Astronomical_unit" title="Astronomical unit">AU</a></span> on 8 December 2019.<sup id="cite_ref-JPL-Data_4-2" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-NYT-20191207b_16-0" class="reference"><a href="#cite_note-NYT-20191207b-16"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> The comet passed closest to Earth on 28 December 2019.<sup id="cite_ref-Guzik2019_17-0" class="reference"><a href="#cite_note-Guzik2019-17"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> In November 2019, astronomers from <a href="/wiki/Yale_University" title="Yale University">Yale University</a> said that the comet's tail was 14 times the size of Earth, and stated, "It's humbling to realize how small Earth is next to this visitor from another solar system."<sup id="cite_ref-YALE-20191126_18-0" class="reference"><a href="#cite_note-YALE-20191126-18"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Nomenclature">Nomenclature</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=1" title="Edit section: Nomenclature"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The comet is formally called "2I/Borisov" by the <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">International Astronomical Union</a> (IAU), with "2I" or "2I/2019 Q4" being its designation and "Borisov" being its name, but is sometimes referred to as "Comet Borisov", especially in the popular press.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>c<span class="cite-bracket">]</span></a></sup> As the second observed interstellar interloper after <a href="/wiki/%CA%BBOumuamua" title="ʻOumuamua">1I/ʻOumuamua</a>, it was given the "2I" <a href="/wiki/Naming_of_comets#Current_system" title="Naming of comets">designation</a>, where "I" stands for interstellar.<sup id="cite_ref-Christensen2019_20-0" class="reference"><a href="#cite_note-Christensen2019-20"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-MPEC2019-S72_10-1" class="reference"><a href="#cite_note-MPEC2019-S72-10"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> The name Borisov follows the tradition of naming comets after their discoverers. Before final designation as 2I/Borisov, the object was referred to by other names: </p> <ul><li>Early orbit solutions suggested that the comet could be a <a href="/wiki/Near-Earth_object" title="Near-Earth object">near-Earth object</a> and was thus listed on <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">IAU</a>'s <a href="/wiki/Minor_Planet_Center" title="Minor Planet Center">Minor Planet Center</a>'s (MPC) <a href="/wiki/Near-Earth_Object_Confirmation_Page" title="Near-Earth Object Confirmation Page">Near-Earth Object Confirmation Page</a> (NEOCP) as gb00234.<sup id="cite_ref-Gray-NEO_21-0" class="reference"><a href="#cite_note-Gray-NEO-21"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup></li> <li>Further refinements after thirteen days of observation made clear the object was a hyperbolic comet, and it was given the designation C/2019 Q4 (Borisov) by the Minor Planet Center on 11 September 2019.<sup id="cite_ref-MPECK19RA6_22-0" class="reference"><a href="#cite_note-MPECK19RA6-22"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> A number of other astronomers including <a href="/w/index.php?title=Davide_Farnocchia&action=edit&redlink=1" class="new" title="Davide Farnocchia (page does not exist)">Davide Farnocchia</a>, <a href="/w/index.php?title=Bill_Gray_(astronomer)&action=edit&redlink=1" class="new" title="Bill Gray (astronomer) (page does not exist)">Bill Gray</a>, and <a href="/wiki/David_Tholen" class="mw-redirect" title="David Tholen">David Tholen</a> concluded that the comet was interstellar.<sup id="cite_ref-MPECK19RA6_22-1" class="reference"><a href="#cite_note-MPECK19RA6-22"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup></li> <li>On 24 September 2019 the IAU announced that the Working Group for Small Body Nomenclature kept the name Borisov giving the comet the interstellar designation of 2I/Borisov, formally announcing the comet was indeed interstellar.<sup id="cite_ref-Christensen2019_20-1" class="reference"><a href="#cite_note-Christensen2019-20"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-MPEC2019-S72_10-2" class="reference"><a href="#cite_note-MPEC2019-S72-10"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Characteristics">Characteristics</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=2" title="Edit section: Characteristics"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Comet_2I_Borisov_at_Perihelion_in_December_2019.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Comet_2I_Borisov_at_Perihelion_in_December_2019.tif/lossy-page1-220px-Comet_2I_Borisov_at_Perihelion_in_December_2019.tif.jpg" decoding="async" width="220" height="201" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Comet_2I_Borisov_at_Perihelion_in_December_2019.tif/lossy-page1-330px-Comet_2I_Borisov_at_Perihelion_in_December_2019.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Comet_2I_Borisov_at_Perihelion_in_December_2019.tif/lossy-page1-440px-Comet_2I_Borisov_at_Perihelion_in_December_2019.tif.jpg 2x" data-file-width="1826" data-file-height="1666" /></a><figcaption>In this observation, the NASA/ESA Hubble Space Telescope revisited the comet shortly after its closest approach to the Sun in December 2019.</figcaption></figure> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1257001546"><table class="infobox" style="width: 200px; clear: right; float:right;margin:0 0 1.5em 1.5em"><tbody><tr><th colspan="2" class="infobox-above" style="font-size:115%">External videos</th></tr><tr><td colspan="2" class="infobox-full-data" style="text-align: left"><span typeof="mw:File"><span><img alt="video icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Nuvola_apps_kaboodle.svg/16px-Nuvola_apps_kaboodle.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Nuvola_apps_kaboodle.svg/24px-Nuvola_apps_kaboodle.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Nuvola_apps_kaboodle.svg/32px-Nuvola_apps_kaboodle.svg.png 2x" data-file-width="128" data-file-height="128" /></span></span> <a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=_jjSTnH7xmk">Interstellar comet 2I/Borisov at perihelion (8 December 2019). </a></td></tr></tbody></table> <p>Unlike ʻOumuamua, which had an <a href="/wiki/Asteroid" title="Asteroid">asteroidal</a> appearance, 2I/Borisov's nucleus was surrounded by a <a href="/wiki/Coma_(cometary)" class="mw-redirect" title="Coma (cometary)">coma</a>, a cloud of dust and gas.<sup id="cite_ref-Greskno2019_23-0" class="reference"><a href="#cite_note-Greskno2019-23"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif/lossy-page1-220px-Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif.jpg" decoding="async" width="220" height="202" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif/lossy-page1-330px-Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif/lossy-page1-440px-Comet_2I_Borisov_and_Distant_Galaxy_in_November_2019.tif.jpg 2x" data-file-width="1817" data-file-height="1665" /></a><figcaption>Comet 2I/Borisov and a distant galaxy (2MASX J10500165-0152029<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup>) in November 2019.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup></figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="Size_and_shape">Size and shape</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=3" title="Edit section: Size and shape"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Early estimates of nucleus 2I/Borisov diameter have ranged from <span class="nowrap"><span data-sort-value="7003140000000000000♠"></span>1.4 to 16 km</span>.<sup id="cite_ref-NASA-Initial_26-0" class="reference"><a href="#cite_note-NASA-Initial-26"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> 2I/Borisov has, unlike Solar System comets, noticeably shrunk during Solar System flyby, losing at least 0.4% of its mass before <a href="/wiki/Apsis" title="Apsis">perihelion</a>.<sup id="cite_ref-Hui2020_9-1" class="reference"><a href="#cite_note-Hui2020-9"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> Also, the amplitude of non-gravitational acceleration place an upper limit of 0.4 km on nucleus size, consistent with a previous <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a> upper limit of 0.5 km.<sup id="cite_ref-Jewitt2019b_8-1" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> The comet did not come much closer to Earth than 300 million km, which prevents using radar to directly determine its size and shape. This could be done using the <a href="/wiki/Occultation" title="Occultation">occultation</a> of a star by 2I/Borisov but an occultation would be difficult to predict, requiring a precise determination of its orbit, and the detection would necessitate a network of small telescopes.<sup id="cite_ref-Bamberger2019_28-0" class="reference"><a href="#cite_note-Bamberger2019-28"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Rotation">Rotation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=4" title="Edit section: Rotation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A study using observations from Hubble could not find a variation in the light curve. According to this study the rotational period must be larger than 10 hours.<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> A study with <a href="/wiki/Canadian_Space_Agency" title="Canadian Space Agency">CSA</a>'s <a href="/wiki/Near_Earth_Object_Surveillance_Satellite" title="Near Earth Object Surveillance Satellite">NEOSSat</a> found a period of 13.2 ± 0.2 days, which is unlikely to be the nuclear spin.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Monte_Carlo_method" title="Monte Carlo method">Monte Carlo</a> simulations based on the available orbit determinations suggest that the equatorial obliquity of 2I/Borisov could be about 59 degrees or 90 degrees, the latter is favored for the latest orbit determination.<sup id="cite_ref-rotationpole_31-0" class="reference"><a href="#cite_note-rotationpole-31"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Chemical_makeup_and_nucleus_structure">Chemical makeup and nucleus structure</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=5" title="Edit section: Chemical makeup and nucleus structure"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/David_C._Jewitt" title="David C. Jewitt">David Jewitt</a> and <a href="/wiki/Jane_Luu" title="Jane Luu">Jane Luu</a> estimate from the size of its coma the comet is producing 2 kg/s of dust and is losing 60 kg/s of water. They extrapolate that it became active in June 2019 when it was between 4 and 5 <style data-mw-deduplicate="TemplateStyles:r920966791">.mw-parser-output span.smallcaps{font-variant:small-caps}.mw-parser-output span.smallcaps-smaller{font-size:85%}</style><span class="smallcaps">au</span> from the Sun.<sup id="cite_ref-Jewitt2019b_8-2" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> A search of image archives found <a href="/wiki/Precovery" title="Precovery">precovery</a> observations of 2I/Borisov as early as 13 December 2018, but not on 21 November 2018, indicating it became active between these dates.<sup id="cite_ref-Ye_etal_precovery_32-0" class="reference"><a href="#cite_note-Ye_etal_precovery-32"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p><p>2I/Borisov's composition appears uncommon yet not unseen in Solar System comets, being relatively depleted in water and <a href="/wiki/Diatomic_carbon" title="Diatomic carbon">diatomic carbon</a> (C<sub>2</sub>), but enriched in <a href="/wiki/Carbon_monoxide" title="Carbon monoxide">carbon monoxide</a> and <a href="/wiki/Amines" class="mw-redirect" title="Amines">amines</a> (R-NH<sub>2</sub>).<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> The molar ratio of carbon monoxide to water in 2I/Borisov tail is 35–105%, resembling the unusual blue-tailed comet <a href="/wiki/C/2016_R2_(PANSTARRS)" class="mw-redirect" title="C/2016 R2 (PANSTARRS)">C/2016 R2 (PANSTARRS)</a> in contrast to the average ratio of 4% for solar system comets.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> </p><p>The 2I/Borisov has also produced a minor amount of neutral nickel emission attributed to an unknown volatile compound of nickel.<sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> The nickel to iron abundance ratio is similar to Solar System comets.<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Trajectory">Trajectory</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=6" title="Edit section: Trajectory"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Sky_plot_13.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Sky_plot_13.png/220px-Sky_plot_13.png" decoding="async" width="220" height="156" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Sky_plot_13.png/330px-Sky_plot_13.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/ab/Sky_plot_13.png/440px-Sky_plot_13.png 2x" data-file-width="762" data-file-height="542" /></a><figcaption>Trajectory across sky in cylindrical coordinates, with 30 August 2019 discovery position along with precovery positions marked back to 13 December 2018 which help narrow down the incoming trajectory</figcaption></figure> <table class="wikitable floatright" style="text-align:center; font-size:0.9em;"> <caption>Interstellar velocity inbound (<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle v_{\infty }}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>v</mi> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">∞</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle v_{\infty }}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/26145027656115364f96e031bca0c0c11022986e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.003ex; height:2.009ex;" alt="{\displaystyle v_{\infty }}"></span>)<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>d<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <th>Object</th> <th>Velocity </th></tr> <tr> <td><a href="/wiki/1I/2017_U1_(%CA%BBOumuamua)" class="mw-redirect" title="1I/2017 U1 (ʻOumuamua)">1I/2017 U1 (ʻOumuamua)</a></td> <td>26.33 km/s<br />5.55 AU/yr<sup id="cite_ref-ProjectPluto_38-0" class="reference"><a href="#cite_note-ProjectPluto-38"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td><b>2I/2019 Q4 (Borisov)</b></td> <td>32.2 km/s<br />6.79 AU/yr<sup id="cite_ref-Gray-FAQ_39-0" class="reference"><a href="#cite_note-Gray-FAQ-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> </td></tr></tbody></table> <p>As seen from Earth, the comet was in the northern sky from September until mid-November. It crossed the ecliptic plane on 26 October near the star <a href="/wiki/Regulus" title="Regulus">Regulus</a>,<sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> and the <a href="/wiki/Celestial_equator" title="Celestial equator">celestial equator</a> on 13 November 2019, entering the southern sky. On 8 December 2019, the comet reached <a href="/wiki/Apsis" title="Apsis">perihelion</a> (closest approach to the Sun)<sup id="cite_ref-JPL-Data_4-3" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> and was near the inner edge of the asteroid belt. In late December, it made its closest approach to Earth,<sup id="cite_ref-NYT-20191207a_13-1" class="reference"><a href="#cite_note-NYT-20191207a-13"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-NYT-20191207b_16-1" class="reference"><a href="#cite_note-NYT-20191207b-16"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> 1.9 <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r920966791"><span class="smallcaps">au</span>, and had a solar elongation of about 80°.<sup id="cite_ref-Gray234_7-1" class="reference"><a href="#cite_note-Gray234-7"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Due to its 44° <a href="/wiki/Orbital_inclination" title="Orbital inclination">orbital inclination</a>, 2I/Borisov did not make any notable close approaches to the planets.<sup id="cite_ref-JPL-Data_4-4" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> 2I/Borisov entered the Solar System from the direction of <a href="/wiki/Cassiopeia_(constellation)" title="Cassiopeia (constellation)">Cassiopeia</a> near the border with <a href="/wiki/Perseus_(constellation)" title="Perseus (constellation)">Perseus</a>. This direction indicates that it originates from the <a href="/wiki/Galactic_plane" title="Galactic plane">galactic plane</a>, rather than from the <a href="/wiki/Galactic_halo" title="Galactic halo">galactic halo</a>.<sup id="cite_ref-Gray-FAQ_39-1" class="reference"><a href="#cite_note-Gray-FAQ-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-deLeón2020_41-0" class="reference"><a href="#cite_note-deLeón2020-41"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> It will leave the Solar System in the direction of <a href="/wiki/Telescopium" title="Telescopium">Telescopium</a>.<sup id="cite_ref-Gray-FAQ_39-2" class="reference"><a href="#cite_note-Gray-FAQ-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-deLeón2020_41-1" class="reference"><a href="#cite_note-deLeón2020-41"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> In interstellar space, 2I/Borisov takes roughly <span class="nowrap"><span data-sort-value="7003900000000000000♠"></span>9000</span> years to travel a <a href="/wiki/Light-year" title="Light-year">light-year</a> relative to the Sun.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>e<span class="cite-bracket">]</span></a></sup> </p><p>2I/Borisov's trajectory is extremely <a href="/wiki/Hyperbolic_trajectory" title="Hyperbolic trajectory">hyperbolic</a>, having an <a href="/wiki/Orbital_eccentricity" title="Orbital eccentricity">orbital eccentricity</a> of 3.36.<sup id="cite_ref-JPL-Data_4-5" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-MPC-DB_6-2" class="reference"><a href="#cite_note-MPC-DB-6"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> This is much higher than the 300+ known weakly <a href="/wiki/List_of_hyperbolic_comets" title="List of hyperbolic comets">hyperbolic comets</a>, with heliocentric eccentricities just over 1, and even ʻOumuamua with an eccentricity of 1.2.<sup id="cite_ref-JPL-Hyperbolic_43-0" class="reference"><a href="#cite_note-JPL-Hyperbolic-43"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-44" class="reference"><a href="#cite_note-44"><span class="cite-bracket">[</span>f<span class="cite-bracket">]</span></a></sup> 2I/Borisov also has a <a href="/wiki/Hyperbolic_excess_velocity" class="mw-redirect" title="Hyperbolic excess velocity">hyperbolic excess velocity</a> (<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle v_{\infty }}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>v</mi> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="normal">∞</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle v_{\infty }}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/26145027656115364f96e031bca0c0c11022986e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.003ex; height:2.009ex;" alt="{\displaystyle v_{\infty }}"></span>) of <span class="nowrap"><span data-sort-value="7004320000000000000♠"></span>32 km/s</span>, much higher than what could be explained by perturbations, which could produce velocities when approaching an infinite distance from the Sun of less than a few km/s.<sup id="cite_ref-Siegel2017_45-0" class="reference"><a href="#cite_note-Siegel2017-45"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> These two parameters are important indicators of 2I/Borisov's interstellar origin.<sup id="cite_ref-Gray-FAQ_39-3" class="reference"><a href="#cite_note-Gray-FAQ-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Atel13100_46-0" class="reference"><a href="#cite_note-Atel13100-46"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> For comparison, the <i><a href="/wiki/Voyager_1" title="Voyager 1">Voyager 1</a></i> spacecraft, which is leaving the Solar System, is traveling at 16.9 km/s (3.57 AU/a).<sup id="cite_ref-Voyager_47-0" class="reference"><a href="#cite_note-Voyager-47"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> 2I/Borisov has a much larger eccentricity than ʻOumuamua due to its higher excess velocity and its significantly higher perihelion distance. At this larger distance, the Sun's gravity is less able to alter its path as it passes through the Solar System.<sup id="cite_ref-Gray-FAQ_39-4" class="reference"><a href="#cite_note-Gray-FAQ-39"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> </p> <style data-mw-deduplicate="TemplateStyles:r1237032888/mw-parser-output/.tmulti">.mw-parser-output .tmulti .multiimageinner{display:flex;flex-direction:column}.mw-parser-output .tmulti .trow{display:flex;flex-direction:row;clear:left;flex-wrap:wrap;width:100%;box-sizing:border-box}.mw-parser-output .tmulti .tsingle{margin:1px;float:left}.mw-parser-output .tmulti .theader{clear:both;font-weight:bold;text-align:center;align-self:center;background-color:transparent;width:100%}.mw-parser-output .tmulti .thumbcaption{background-color:transparent}.mw-parser-output .tmulti .text-align-left{text-align:left}.mw-parser-output .tmulti .text-align-right{text-align:right}.mw-parser-output .tmulti .text-align-center{text-align:center}@media all and (max-width:720px){.mw-parser-output .tmulti .thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner img{background-color:white}}</style><div class="thumb tmulti tnone center"><div class="thumbinner multiimageinner" style="width:965px;max-width:965px"><div class="trow"><div class="theader">2I/Borisov — orbit diagrams</div></div><div class="trow"><div class="tsingle" style="width:283px;max-width:283px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/58/A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif/281px-A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif" decoding="async" width="281" height="232" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/58/A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif/422px-A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/58/A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif/562px-A_comparison_of_two_interstellar_objects_passing_through_our_solar_system.gif 2x" data-file-width="750" data-file-height="619" /></a></span></div><div class="thumbcaption text-align-center">Trajectory of Borisov (yellow) crossing the ecliptic plane; 'Oumuamua (red) shown for comparison</div></div><div class="tsingle" style="width:262px;max-width:262px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:Interstellar_visitors.jpg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Interstellar_visitors.jpg/260px-Interstellar_visitors.jpg" decoding="async" width="260" height="232" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Interstellar_visitors.jpg/390px-Interstellar_visitors.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Interstellar_visitors.jpg/520px-Interstellar_visitors.jpg 2x" data-file-width="1079" data-file-height="962" /></a></span></div><div class="thumbcaption text-align-center">Borisov approaches the ecliptic plane between the orbits of Jupiter (pink) and Mars (orange)</div></div><div class="tsingle" style="width:414px;max-width:414px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:Comet-2I-Borisov-Orbit-JPL.png" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/Comet-2I-Borisov-Orbit-JPL.png/412px-Comet-2I-Borisov-Orbit-JPL.png" decoding="async" width="412" height="232" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/74/Comet-2I-Borisov-Orbit-JPL.png/618px-Comet-2I-Borisov-Orbit-JPL.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/74/Comet-2I-Borisov-Orbit-JPL.png/824px-Comet-2I-Borisov-Orbit-JPL.png 2x" data-file-width="1920" data-file-height="1080" /></a></span></div><div class="thumbcaption text-align-center">Borisov's trajectory and position (white) as of 13 October 2019 (top view)</div></div></div></div></div> <div class="mw-heading mw-heading2"><h2 id="Observation">Observation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=7" title="Edit section: Observation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Discovery">Discovery</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=8" title="Edit section: Discovery"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The comet was discovered on 30 August 2019 by <a href="/wiki/Amateur_astronomer" class="mw-redirect" title="Amateur astronomer">amateur astronomer</a> <a href="/wiki/Gennadiy_Borisov" title="Gennadiy Borisov">Gennadiy Borisov</a> at his personal observatory <a href="/wiki/List_of_observatory_codes#L51" title="List of observatory codes">MARGO</a> in Nauchnyy, <a href="/wiki/Crimea" title="Crimea">Crimea</a>, using a 0.65 meter telescope he designed and built himself.<sup id="cite_ref-S&T2019_48-0" class="reference"><a href="#cite_note-S&T2019-48"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> The discovery has been compared to the discovery of <a href="/wiki/Pluto" title="Pluto">Pluto</a> by <a href="/wiki/Clyde_Tombaugh" title="Clyde Tombaugh">Clyde Tombaugh</a>.<sup id="cite_ref-Fontanka_49-0" class="reference"><a href="#cite_note-Fontanka-49"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> Tombaugh was also an amateur astronomer who was building his own telescopes, although he discovered Pluto using <a href="/wiki/Lowell_Observatory" title="Lowell Observatory">Lowell Observatory</a>'s <a href="/wiki/Astrograph" title="Astrograph">astrograph</a>. At discovery, it was inbound <span class="nowrap"><span data-sort-value="7011448793612100000♠"></span>3 AU</span> from the Sun, <span class="nowrap"><span data-sort-value="7011553512121590000♠"></span>3.7 AU</span> from Earth, and had a <a href="/wiki/Solar_elongation" class="mw-redirect" title="Solar elongation">solar elongation</a> of 38°.<sup id="cite_ref-Gray-prec_50-0" class="reference"><a href="#cite_note-Gray-prec-50"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> Borisov described his discovery thus:<sup id="cite_ref-RIA_51-0" class="reference"><a href="#cite_note-RIA-51"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup> </p> <div style="clear:both;" class=""></div> <table class="wikitable floatright" style="text-align:center; font-size:0.9em;"> <caption>JPL Scout eccentricity ranges<sup id="cite_ref-archive-is_52-0" class="reference"><a href="#cite_note-archive-is-52"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <th># of<br />observations </th> <th>Observation<br />arc (hours) </th> <th>Eccentricity<br />range </th></tr> <tr> <td>81</td> <td>225</td> <td>0.9–1.6 </td></tr> <tr> <td>99</td> <td>272</td> <td>2.0–4.2 </td></tr> <tr> <td>127</td> <td>289</td> <td>2.8–4.7 </td></tr> <tr> <td>142</td> <td>298</td> <td>2.8–4.5 </td></tr> <tr> <td>151</td> <td>302</td> <td>2.9–4.5 </td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r1244412712">.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 32px}.mw-parser-output .templatequotecite{line-height:1.5em;text-align:left;margin-top:0}@media(min-width:500px){.mw-parser-output .templatequotecite{padding-left:1.6em}}</style><blockquote class="templatequote"><p>I observed it on August 29, but it was August 30 <a href="/wiki/GMT" class="mw-redirect" title="GMT">Greenwich Time</a>.<sup id="cite_ref-54" class="reference"><a href="#cite_note-54"><span class="cite-bracket">[</span>g<span class="cite-bracket">]</span></a></sup> I saw a moving object in the frame, it moved in a direction that was slightly different from that of <a href="/wiki/Main-belt" class="mw-redirect" title="Main-belt">main asteroids</a>.<sup id="cite_ref-56" class="reference"><a href="#cite_note-56"><span class="cite-bracket">[</span>h<span class="cite-bracket">]</span></a></sup> I measured its coordinates and consulted the <a href="/wiki/Minor_Planet_Center" title="Minor Planet Center">Minor Planet Center</a> database. Turned out, it was a new object. Then I measured the near-Earth object rating,<sup id="cite_ref-58" class="reference"><a href="#cite_note-58"><span class="cite-bracket">[</span>i<span class="cite-bracket">]</span></a></sup> it is calculated from various parameters, and it turned out to be 100% – in other words, <a href="/wiki/Potentially_hazardous_object" title="Potentially hazardous object">dangerous</a>. In such cases I must immediately post the parameters to the world webpage for confirmation of dangerous asteroids.<sup id="cite_ref-60" class="reference"><a href="#cite_note-60"><span class="cite-bracket">[</span>j<span class="cite-bracket">]</span></a></sup> I posted it and wrote that the object was diffuse and that it was not an asteroid, but a comet.</p></blockquote> <p>2I/Borisov's interstellar origin required a couple of weeks to confirm. Early orbital solutions based on initial observations included the possibility that the comet could be a near-Earth object 1.4 AU from the Sun in an elliptical orbit with an orbital period of less than 1 year.<sup id="cite_ref-Gray-NEO_21-1" class="reference"><a href="#cite_note-Gray-NEO-21"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> Later using 151 observations over 12 days, <a href="/wiki/NASA" title="NASA">NASA</a> <a href="/wiki/Jet_Propulsion_Laboratory" title="Jet Propulsion Laboratory">Jet Propulsion Laboratory</a>'s <a href="/wiki/Sentry_(monitoring_system)#Scout" title="Sentry (monitoring system)">Scout</a> gave an eccentricity range of 2.9–4.5 .<sup id="cite_ref-Scout_61-0" class="reference"><a href="#cite_note-Scout-61"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> But with an <a href="/wiki/Observation_arc" title="Observation arc">observation arc</a> of only 12 days, there was still some doubt that it was interstellar because the observations were at a low solar elongation, which could introduce biases in the data such as <a href="/wiki/Atmospheric_refraction" title="Atmospheric refraction">differential refraction</a>. Using large non-gravitational forces on the highly eccentric orbit, a solution could be generated with an eccentricity of about 1, an Earth <a href="/wiki/Minimum_orbit_intersection_distance" title="Minimum orbit intersection distance">minimum orbit intersection distance</a> (MOID) of 0.34 AU (51 million km), and a perihelion at 0.90 AU around 30 December 2019.<sup id="cite_ref-Gray35237_62-0" class="reference"><a href="#cite_note-Gray35237-62"><span class="cite-bracket">[</span>52<span class="cite-bracket">]</span></a></sup> However, based on available observations, the orbit could only be parabolic if non-gravitational forces (thrust due to outgassing) affected its orbit more than any previous comets.<sup id="cite_ref-Gray234c_63-0" class="reference"><a href="#cite_note-Gray234c-63"><span class="cite-bracket">[</span>53<span class="cite-bracket">]</span></a></sup> Eventually with more observations the orbit converged to the hyperbolic solution that indicated an interstellar origin and non-gravitational forces could not explain the motion.<sup id="cite_ref-MPECK19RA6_22-2" class="reference"><a href="#cite_note-MPECK19RA6-22"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Observation_2">Observation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=9" title="Edit section: Observation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><span><video id="mwe_player_0" poster="//upload.wikimedia.org/wikipedia/commons/thumb/1/13/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm/220px--Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm.jpg" controls="" preload="none" data-mw-tmh="" class="mw-file-element" width="220" height="124" data-durationhint="103" data-mwtitle="Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm" data-mwprovider="wikimediacommons" resource="/wiki/File:Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/1/13/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm.360p.vp9.webm" type="video/webm; codecs="vp9, opus"" data-transcodekey="360p.vp9.webm" data-width="640" data-height="360" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/1/13/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm.360p.webm" type="video/webm; codecs="vp8, vorbis"" data-transcodekey="360p.webm" data-width="640" data-height="360" /><source src="//upload.wikimedia.org/wikipedia/commons/1/13/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm" type="video/webm; codecs="vp8, opus"" data-width="640" data-height="360" /><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/1/13/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm/Video-NASA-InterstellarComet-2IBorisov-HubbleST-20191016.webm.240p.vp9.webm" type="video/webm; codecs="vp9, opus"" data-transcodekey="240p.vp9.webm" data-width="426" data-height="240" /></video></span><figcaption>Hubble started observations of 2I/Borisov in October 2019, two months prior to the comet's closest approach to the Sun</figcaption></figure> <p>The last observations were in July 2020, seven months after perihelion.<sup id="cite_ref-JPL-Data_4-6" class="reference"><a href="#cite_note-JPL-Data-4"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> Observation of 2I/Borisov was aided by the fact that the comet was detected while inbound towards the Solar System. ʻOumuamua had been discovered as it was leaving the system, and thus could only be observed for 80 days before it was out of range. Because of its closest approach occurring near traditional year-end holidays, and the capability to have extended observations, some astronomers have called 2I/Borisov a "Christmas comet".<sup id="cite_ref-NYT-20191224_15-1" class="reference"><a href="#cite_note-NYT-20191224-15"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-NYT-20191001_64-0" class="reference"><a href="#cite_note-NYT-20191001-64"><span class="cite-bracket">[</span>54<span class="cite-bracket">]</span></a></sup> Observations using the <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a> began on 12 October, when the comet moved far enough from the Sun to be safely observed by the telescope.<sup id="cite_ref-Hubble100719_65-0" class="reference"><a href="#cite_note-Hubble100719-65"><span class="cite-bracket">[</span>55<span class="cite-bracket">]</span></a></sup> Hubble is less affected by the confounding effects of the coma than ground-based telescopes, which will allow it to study the rotational <a href="/wiki/Light_curve" title="Light curve">light curve</a> of 2I/Borisov's nucleus. This should facilitate an estimate of its size and shape.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Manual_of_Style/Dates_and_numbers#Chronological_items" title="Wikipedia:Manual of Style/Dates and numbers"><span title="The date of the event predicted near this tag has passed. (April 2022)">needs update</span></a></i>]</sup> </p> <div class="mw-heading mw-heading3"><h3 id="Comet_chemistry">Comet chemistry</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=10" title="Edit section: Comet chemistry"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A preliminary (low-resolution) visible spectrum of 2I/Borisov was similar to typical <a href="/wiki/Oort_Cloud" class="mw-redirect" title="Oort Cloud">Oort Cloud</a> comets.<sup id="cite_ref-IAC_66-0" class="reference"><a href="#cite_note-IAC-66"><span class="cite-bracket">[</span>56<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-deLeón2019_67-0" class="reference"><a href="#cite_note-deLeón2019-67"><span class="cite-bracket">[</span>57<span class="cite-bracket">]</span></a></sup> Its <a href="/wiki/Color_index" title="Color index">color indexes</a> also resemble the Solar System's long period comets.<sup id="cite_ref-Jewitt2019b_8-3" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Emissions at <span class="nowrap"><span data-sort-value="6993388000000000000♠"></span>388 <a href="/wiki/Nanometre" title="Nanometre">nm</a></span> indicated the presence of <a href="/wiki/Cyanide" title="Cyanide">cyanide</a> (formula CN), which is typically the first detected in Solar System comets including <a href="/wiki/Comet_Halley" class="mw-redirect" title="Comet Halley">comet Halley</a>.<sup id="cite_ref-Fitzsimmons2019_68-0" class="reference"><a href="#cite_note-Fitzsimmons2019-68"><span class="cite-bracket">[</span>58<span class="cite-bracket">]</span></a></sup> This was the first detection of gas emissions from an interstellar object.<sup id="cite_ref-CBAT4670_69-0" class="reference"><a href="#cite_note-CBAT4670-69"><span class="cite-bracket">[</span>59<span class="cite-bracket">]</span></a></sup> The non-detection of diatomic carbon had also been reported in October 2019, with the ratio C<sub>2</sub> to CN being less than either 0.095<sup id="cite_ref-Kareta2019_70-0" class="reference"><a href="#cite_note-Kareta2019-70"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup> or 0.3 .<sup id="cite_ref-Opitom2019_71-0" class="reference"><a href="#cite_note-Opitom2019-71"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup> The diatomic carbon was positively detected in November 2019, with measured C<sub>2</sub> to CN ratio of <span class="nowrap"><span data-sort-value="6999200000000000000♠"></span>0.2<span style="margin-left:0.3em;margin-right:0.15em;">±</span>0.1</span> .<sup id="cite_ref-72" class="reference"><a href="#cite_note-72"><span class="cite-bracket">[</span>62<span class="cite-bracket">]</span></a></sup> This resembles a carbon-chain depleted group of comets, which are either Jupiter family comets<sup id="cite_ref-Kareta2019_70-1" class="reference"><a href="#cite_note-Kareta2019-70"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup> or rare blue-colored carbon monoxide comets exemplified by <a href="/wiki/C/2016_R2" class="mw-redirect" title="C/2016 R2">C/2016 R2</a>.<sup id="cite_ref-73" class="reference"><a href="#cite_note-73"><span class="cite-bracket">[</span>63<span class="cite-bracket">]</span></a></sup> By the end of November 2019, C<sub>2</sub> production had dramatically increased, and C<sub>2</sub> to CN ratio reached 0.61, along with appearance of bright amine (NH<sub>2</sub>) bands.<sup id="cite_ref-74" class="reference"><a href="#cite_note-74"><span class="cite-bracket">[</span>64<span class="cite-bracket">]</span></a></sup> Atomic oxygen has also been detected, from this observers estimated an outgassing of water at a rate similar to Solar System comets.<sup id="cite_ref-SA-20191030_75-0" class="reference"><a href="#cite_note-SA-20191030-75"><span class="cite-bracket">[</span>65<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ARX-20191028_76-0" class="reference"><a href="#cite_note-ARX-20191028-76"><span class="cite-bracket">[</span>66<span class="cite-bracket">]</span></a></sup> Initially, neither water nor OH lines were directly detected<sup id="cite_ref-77" class="reference"><a href="#cite_note-77"><span class="cite-bracket">[</span>67<span class="cite-bracket">]</span></a></sup> in September 2019. First unambiguous detection of OH lines was done 1 November 2019, and OH production peaked in early December 2019.<sup id="cite_ref-78" class="reference"><a href="#cite_note-78"><span class="cite-bracket">[</span>68<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Suspected_nucleus_fragmentation">Suspected nucleus fragmentation</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=11" title="Edit section: Suspected nucleus fragmentation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The comet did come within about 2 AU of the Sun, a distance at which many small comets have been found to disintegrate. The probability that a comet disintegrates strongly depends on the size of its nucleus; Guzik et al. estimated a probability of 10% that this would happen to 2I/Borisov.<sup id="cite_ref-Guzik2019_17-1" class="reference"><a href="#cite_note-Guzik2019-17"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Jewitt and Luu compared 2I/Borisov to C/2019 J2 (Palomar), another comet of similar size that disintegrated in May 2019 at a distance of 1.9 AU from the Sun.<sup id="cite_ref-Jewitt2019a_79-0" class="reference"><a href="#cite_note-Jewitt2019a-79"><span class="cite-bracket">[</span>69<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Jewitt2019b_8-4" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> In the event that the nucleus disintegrates, as is sometimes seen with small comets, Hubble can be used to study the evolution of the disintegration process.<sup id="cite_ref-STScI-16009_80-0" class="reference"><a href="#cite_note-STScI-16009-80"><span class="cite-bracket">[</span>70<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Jewitt2019b_8-5" class="reference"><a href="#cite_note-Jewitt2019b-8"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>The severe outburst in February–March 2020, led to suspected "ongoing nucleus fragmentation" from the comet by 12 March.<sup id="cite_ref-AT-20200312_81-0" class="reference"><a href="#cite_note-AT-20200312-81"><span class="cite-bracket">[</span>71<span class="cite-bracket">]</span></a></sup> Indeed, images from the Hubble Space Telescope taken on 30 March 2020 show a non-stellar core indicating that Comet 2I/Borisov has ejected sunward a large fragment.<sup id="cite_ref-AT-20200402_82-0" class="reference"><a href="#cite_note-AT-20200402-82"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-AT-20200403_83-0" class="reference"><a href="#cite_note-AT-20200403-83"><span class="cite-bracket">[</span>73<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-SA-20200403_84-0" class="reference"><a href="#cite_note-SA-20200403-84"><span class="cite-bracket">[</span>74<span class="cite-bracket">]</span></a></sup> The ejection is estimated to have begun around 7 March,<sup id="cite_ref-Bolin_fragmentation_85-0" class="reference"><a href="#cite_note-Bolin_fragmentation-85"><span class="cite-bracket">[</span>75<span class="cite-bracket">]</span></a></sup> and may have occurred during one of the outbursts that occurred near that time.<sup id="cite_ref-Drahus_outburst_86-0" class="reference"><a href="#cite_note-Drahus_outburst-86"><span class="cite-bracket">[</span>76<span class="cite-bracket">]</span></a></sup> The ejected fragment appeared to have vanished by 6 April 2020.<sup id="cite_ref-AT-20200406_87-0" class="reference"><a href="#cite_note-AT-20200406-87"><span class="cite-bracket">[</span>77<span class="cite-bracket">]</span></a></sup> </p><p>A followup study, reported on 6 April 2020, observed only a single object, and noted that the fragment component had now disappeared.<sup id="cite_ref-AT-20200406_87-1" class="reference"><a href="#cite_note-AT-20200406-87"><span class="cite-bracket">[</span>77<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-NYT-20200407_88-0" class="reference"><a href="#cite_note-NYT-20200407-88"><span class="cite-bracket">[</span>78<span class="cite-bracket">]</span></a></sup> Later analysis of the event showed the ejected dust and fragments have a combined mass of about 0.1% of total mass of nucleus, making the event a large outburst rather than fragmentation.<sup id="cite_ref-89" class="reference"><a href="#cite_note-89"><span class="cite-bracket">[</span>79<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Exploration">Exploration</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=12" title="Edit section: Exploration"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The high hyperbolic excess velocity of 2I/Borisov of <span class="nowrap"><span data-sort-value="7004320000000000000♠"></span>32 km/s</span> makes it hard for a spacecraft to reach the comet with existing technology: according to a team of the <a href="/wiki/Initiative_for_Interstellar_Studies" title="Initiative for Interstellar Studies">Initiative for Interstellar Studies</a>, a 202 kg (445 lb) spacecraft could theoretically have been sent in July 2018 to intercept 2I/Borisov using a <a href="/wiki/Falcon_Heavy" title="Falcon Heavy">Falcon Heavy</a>-class launcher, or 765 kg (1687 lb) on a <a href="/wiki/Space_Launch_System" title="Space Launch System">Space Launch System</a> (SLS)-class booster, but only if the object had been discovered much earlier than it was to meet the optimal launch date. Launches after the actual discovery date would eliminate the possibility to use Falcon Heavy-class rockets, requiring <a href="/wiki/Oberth_effect" title="Oberth effect">Oberth maneuvres</a> near Jupiter and near the Sun and a larger launch vehicle. Even an SLS-class launcher would only have been able to deliver a 3 kg (6.6 lb) payload (such as a <a href="/wiki/CubeSat" title="CubeSat">CubeSat</a>) into a trajectory that would intercept 2I/Borisov in 2045 at a relative speed of <span class="nowrap"><span data-sort-value="7004340000000000000♠"></span>34 km/s</span>.<sup id="cite_ref-Hibberd2019_90-0" class="reference"><a href="#cite_note-Hibberd2019-90"><span class="cite-bracket">[</span>80<span class="cite-bracket">]</span></a></sup> According to congressional testimony, NASA may need at least five years of preparation to launch such an <a href="/wiki/Asteroid_impact_avoidance#Deflection_efforts" title="Asteroid impact avoidance">intercepting mission</a>.<sup id="cite_ref-US-Congress-20130410_91-0" class="reference"><a href="#cite_note-US-Congress-20130410-91"><span class="cite-bracket">[</span>81<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=13" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/%CA%BBOumuamua" title="ʻOumuamua">ʻOumuamua</a> - the first interstellar interloper discovered</li> <li>Blue (carbon monoxide rich) comets <ul><li><a href="/wiki/Comet_Morehouse" title="Comet Morehouse">Comet Morehouse</a></li> <li><a href="/wiki/Comet_Humason" title="Comet Humason">Comet Humason</a></li> <li><a href="/wiki/C/2016_R2_(PanSTARRS)" title="C/2016 R2 (PanSTARRS)">C/2016 R2</a></li></ul></li> <li><a href="/wiki/C/1980_E1_(Bowell)" title="C/1980 E1 (Bowell)">C/1980 E1 (Bowell)</a> – the most eccentric comet known in the Solar System with an eccentricity of 1.057</li> <li><a href="/wiki/List_of_Solar_System_objects_by_greatest_aphelion" title="List of Solar System objects by greatest aphelion">List of Solar System objects by greatest aphelion</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Notes">Notes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=14" title="Edit section: Notes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-alpha"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text">A photograph of Borisov's dust trail taken on <span class="nowrap">12 October 2019</span> with the UVIS F350LP channel of <a href="/wiki/Wide_Field_Camera_3" title="Wide Field Camera 3">Wide Field Camera 3</a> aboard the <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a>.<sup id="cite_ref-hubblesite-1_1-0" class="reference"><a href="#cite_note-hubblesite-1-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-hubblesite-2_2-0" class="reference"><a href="#cite_note-hubblesite-2-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> At the time of this photograph, Borisov was 418 million km (260 million mi) from <a href="/wiki/Earth" title="Earth">Earth</a>, similar to the average distance of the <a href="/wiki/Ceres_(dwarf_planet)" title="Ceres (dwarf planet)">asteroid Ceres</a> from the <a href="/wiki/Sun" title="Sun">Sun</a>, and traveling at a velocity of 177,000 kilometres per hour (110,000 mph).<sup id="cite_ref-hubblesite-2_2-1" class="reference"><a href="#cite_note-hubblesite-2-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">Objects with eccentricities greater than 1 will have a negative semimajor axis, giving them a positive orbital energy – the smaller the perihelion distance, and the larger above 1 the eccentricity is, the closer to 0 the semimajor axis value will be.</span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text">This is the eighth comet discovered by <a href="/wiki/Gennadiy_Borisov" title="Gennadiy Borisov">Gennadiy Borisov</a>, and thus the ambiguous term "Comet Borisov" is not formally used here.</span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text">For objects gravitationally bound to the Sun, velocities when approaching the equivalent of an infinite distance from the Sun should be less than a few kilometres per second. At its furthest distance from the Sun, Halley's comet moves <span class="nowrap">≈ 1 km/s</span> with respect to the Sun.</span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><a href="/wiki/Speed_of_light" title="Speed of light"><span class="nowrap"><span data-sort-value="7008299792458000000♠"></span>299<span style="margin-left:.25em;">792</span>.458 km/s</span></a> / 32.2 km/s = 9310 times slower than light.</span> </li> <li id="cite_note-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-44">^</a></b></span> <span class="reference-text">A comet with a parabolic trajectory (with an eccentricity of 1) would leave the Solar System in the direction it entered, having had its path altered by 180°. 2I/Borisov, with its higher eccentricity, has a more open trajectory and will have its path altered by only 34° as it passes through the Solar System.</span> </li> <li id="cite_note-54"><span class="mw-cite-backlink"><b><a href="#cite_ref-54">^</a></b></span> <span class="reference-text">This is obviously a mistake: Crimea is 3 hours <i>ahead</i> of Greenwich, so it was August 30 in Crimea when Borisov first observed the comet.<sup id="cite_ref-53" class="reference"><a href="#cite_note-53"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup></span> </li> <li id="cite_note-56"><span class="mw-cite-backlink"><b><a href="#cite_ref-56">^</a></b></span> <span class="reference-text">Of the 850,000 objects known to orbit the Sun, 756,000 (89%) are <a href="/wiki/Main-belt" class="mw-redirect" title="Main-belt">main-belt</a> asteroids.<sup id="cite_ref-55" class="reference"><a href="#cite_note-55"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup></span> </li> <li id="cite_note-58"><span class="mw-cite-backlink"><b><a href="#cite_ref-58">^</a></b></span> <span class="reference-text">The NEO rating calculates the probability that a new object is a near-Earth candidate.<sup id="cite_ref-57" class="reference"><a href="#cite_note-57"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup></span> </li> <li id="cite_note-60"><span class="mw-cite-backlink"><b><a href="#cite_ref-60">^</a></b></span> <span class="reference-text">This refers to the NEO Confirmation Page for confirming near-Earth objects and potentially hazardous objects.<sup id="cite_ref-59" class="reference"><a href="#cite_note-59"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=15" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239543626"><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-hubblesite-1-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-hubblesite-1_1-0">^</a></b></span> <span class="reference-text"> <style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFNational_Aeronautics_and_Space_AdministrationEuropean_Space_AgencyJewitt2019" class="citation web cs1"><a href="/wiki/National_Aeronautics_and_Space_Administration" class="mw-redirect" title="National Aeronautics and Space Administration">National Aeronautics and Space Administration</a>; <a href="/wiki/European_Space_Agency" title="European Space Agency">European Space Agency</a>; <a href="/wiki/David_C._Jewitt" title="David C. Jewitt">Jewitt, David</a> (16 October 2019). <a rel="nofollow" class="external text" href="https://hubblesite.org/contents/media/images/2019/53/4579-Image?news=true">"Comet 2I/Borisov Compass image"</a>. <i><a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubblesite</a></i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20191017024234/https://hubblesite.org/contents/media/images/2019/53/4579-Image?news=true">Archived</a> from the original on 17 October 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">17 October</span> 2019</span>. <q>C/2019 Q4 (Borisov); HST WFC3/UVIS F350LP; Oct. 12, 2019</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Hubblesite&rft.atitle=Comet+2I%2FBorisov+Compass+image&rft.date=2019-10-16&rft.au=National+Aeronautics+and+Space+Administration&rft.au=European+Space+Agency&rft.au=Jewitt%2C+David&rft_id=https%3A%2F%2Fhubblesite.org%2Fcontents%2Fmedia%2Fimages%2F2019%2F53%2F4579-Image%3Fnews%3Dtrue&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-hubblesite-2-2"><span class="mw-cite-backlink">^ <a href="#cite_ref-hubblesite-2_2-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-hubblesite-2_2-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNational_Aeronautics_and_Space_AdministrationEuropean_Space_AgencyJewitt2019" class="citation web cs1"><a href="/wiki/National_Aeronautics_and_Space_Administration" class="mw-redirect" title="National Aeronautics and Space Administration">National Aeronautics and Space Administration</a>; <a href="/wiki/European_Space_Agency" title="European Space Agency">European Space Agency</a>; <a href="/wiki/David_C._Jewitt" title="David C. Jewitt">Jewitt, David</a> (16 October 2019). <a rel="nofollow" class="external text" href="https://hubblesite.org/contents/news-releases/2019/news-2019-53">"Hubble observes cirst confirmed interstellar comet"</a>. <i><a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubblesite</a></i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20191017024151/https://hubblesite.org/contents/news-releases/2019/news-2019-53">Archived</a> from the original on 17 October 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">17 October</span> 2019</span>. <q>Hubble took a series of snapshots as the comet streaked along at 110,000 miles per hour. [...] The comet was 260 million miles from Earth when Hubble took the photo. [...] This Hubble image, taken on 12 October 2019 [...] reveals a central concentration of dust around the nucleus (which is too small to be seen by Hubble).</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Hubblesite&rft.atitle=Hubble+observes+cirst+confirmed+interstellar+comet&rft.date=2019-10-16&rft.au=National+Aeronautics+and+Space+Administration&rft.au=European+Space+Agency&rft.au=Jewitt%2C+David&rft_id=https%3A%2F%2Fhubblesite.org%2Fcontents%2Fnews-releases%2F2019%2Fnews-2019-53&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-JPL-Data-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-JPL-Data_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-JPL-Data_4-6"><sup><i><b>g</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2I">"C/2019 Q4 (Borisov)"</a>. <i>JPL Small-Body Database Browser</i>. <a href="/wiki/Jet_Propulsion_Laboratory" title="Jet Propulsion Laboratory">Jet Propulsion Laboratory</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20191126223110/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2I">Archived</a> from the original on 26 November 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">26 January</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+Small-Body+Database+Browser&rft.atitle=C%2F2019+Q4+%28Borisov%29&rft_id=https%3A%2F%2Fssd.jpl.nasa.gov%2Fsbdb.cgi%3Fsstr%3D2I&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-MPC-DB-6"><span class="mw-cite-backlink">^ <a href="#cite_ref-MPC-DB_6-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-MPC-DB_6-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-MPC-DB_6-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://minorplanetcenter.net/db_search/show_object?object_id=2I">"2I/Borisov = C/2019 Q4 (Borisov)"</a>. <i><a href="/wiki/Minor_Planet_Center" title="Minor Planet Center">Minor Planet Center</a></i>. 1 October 2019<span class="reference-accessdate">. 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Retrieved <span class="nowrap">20 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Project+Pluto&rft.atitle=Pseudo-MPEC+for+gb00234&rft.date=2019-09-20&rft.aulast=Gray&rft.aufirst=Bill&rft_id=https%3A%2F%2Fwww.projectpluto.com%2Ftemp%2Fgb00234.htm%23elements&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Jewitt2019b-8"><span class="mw-cite-backlink">^ <a href="#cite_ref-Jewitt2019b_8-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Jewitt2019b_8-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Jewitt2019b_8-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Jewitt2019b_8-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Jewitt2019b_8-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-Jewitt2019b_8-5"><sup><i><b>f</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJewittLuu2019" class="citation journal cs1">Jewitt, David; Luu, Jane (6 October 2019). <a rel="nofollow" class="external text" href="https://doi.org/10.3847%2F2041-8213%2Fab530b">"Initial Characterization of interstellar comet 2I/2019 Q4 (Borisov)"</a>. <i>The Astrophysical Journal</i>. <b>886</b> (2): L29. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1910.02547">1910.02547</a></span>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2019ApJ...886L..29J">2019ApJ...886L..29J</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.3847%2F2041-8213%2Fab530b">10.3847/2041-8213/ab530b</a></span>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:203837079">203837079</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Initial+Characterization+of+interstellar+comet+2I%2F2019+Q4+%28Borisov%29&rft.volume=886&rft.issue=2&rft.pages=L29&rft.date=2019-10-06&rft_id=info%3Aarxiv%2F1910.02547&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A203837079%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.3847%2F2041-8213%2Fab530b&rft_id=info%3Abibcode%2F2019ApJ...886L..29J&rft.aulast=Jewitt&rft.aufirst=David&rft.au=Luu%2C+Jane&rft_id=https%3A%2F%2Fdoi.org%2F10.3847%252F2041-8213%252Fab530b&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Hui2020-9"><span class="mw-cite-backlink">^ <a href="#cite_ref-Hui2020_9-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Hui2020_9-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHuiYeFöhringHung2020" class="citation arxiv cs1">Hui, Man-To; Ye, Quan-Zhi; Föhring, Dora; Hung, Denise; Tholen, David J. 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Retrieved <span class="nowrap">28 December</span> 2019</span>. <q>Seeing comet Borisov won't be easy for the typical sky gazer, but astronomers still have a lot to learn from this extrasolar tourist.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Watching+an+interstellar+comet+and+hoping+for+a+bang&rft.date=2019-12-24&rft.aulast=St.+Fleur&rft.aufirst=Nicholas&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2019%2F12%2F24%2Fscience%2Finterstellar-comet-christmas.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-NYT-20191207b-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-NYT-20191207b_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-NYT-20191207b_16-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCorum2019" class="citation news cs1">Corum, Jonathan (7 December 2019). <a rel="nofollow" class="external text" href="https://www.nytimes.com/interactive/2019/12/07/science/comet-borisov-tracker.html">"Tracking comet Borisov"</a>. <i><a href="/wiki/The_New_York_Times" title="The New York Times">The New York Times</a></i><span class="reference-accessdate">. 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Retrieved <span class="nowrap">12 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomer%27s+Telegram&rft.atitle=Interstellar+Comet+gb00234&rft_id=http%3A%2F%2Fwww.astronomerstelegram.org%2F%3Fread%3D13100&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Voyager-47"><span class="mw-cite-backlink"><b><a href="#cite_ref-Voyager_47-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://voyager.jpl.nasa.gov/frequently-asked-questions/fast-facts/">"Fast Facts"</a>. <i>Jet Propulsion Laboratory</i>. Voyager<span class="reference-accessdate">. Retrieved <span class="nowrap">27 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Jet+Propulsion+Laboratory&rft.atitle=Fast+Facts&rft_id=https%3A%2F%2Fvoyager.jpl.nasa.gov%2Ffrequently-asked-questions%2Ffast-facts%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-S&T2019-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-S&T2019_48-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKing2019" class="citation news cs1">King, Bob (11 September 2019). <a rel="nofollow" class="external text" href="https://www.skyandtelescope.com/astronomy-news/possible-interstellar-comet-headed-our-way/">"Is another interstellar visitor headed our way?"</a>. <i><a href="/wiki/Sky_%26_Telescope" title="Sky & Telescope">Sky & Telescope</a></i><span class="reference-accessdate">. Retrieved <span class="nowrap">12 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Sky+%26+Telescope&rft.atitle=Is+another+interstellar+visitor+headed+our+way%3F&rft.date=2019-09-11&rft.aulast=King&rft.aufirst=Bob&rft_id=https%3A%2F%2Fwww.skyandtelescope.com%2Fastronomy-news%2Fpossible-interstellar-comet-headed-our-way%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Fontanka-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-Fontanka_49-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFНелюбин2019" class="citation web cs1 cs1-prop-script cs1-prop-foreign-lang-source">Нелюбин, Николай (13 September 2019). <a rel="nofollow" class="external text" href="https://www.fontanka.ru/2019/09/13/052/"><bdi lang="ru">«Готовы открывать кометы бесплатно, лишь бы имя осталось». Российский астроном Геннадий Борисов о первой в истории человечества межзвёздной комете</bdi></a> ["We'll discover comets without pay, what matters is that the name lives on" — Russian astronomer Gennadiy Borisov on the first interstellar comet in the history of humankind.]. <i><a href="/w/index.php?title=Fontanka.ru&action=edit&redlink=1" class="new" title="Fontanka.ru (page does not exist)">Fontanka.ru</a></i> <bdi lang="ru">Фонтанка.ру</bdi> (in Russian)<span class="reference-accessdate">. Retrieved <span class="nowrap">16 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Fontanka.ru&rft.atitle=%C2%AB%D0%93%D0%BE%D1%82%D0%BE%D0%B2%D1%8B+%D0%BE%D1%82%D0%BA%D1%80%D1%8B%D0%B2%D0%B0%D1%82%D1%8C+%D0%BA%D0%BE%D0%BC%D0%B5%D1%82%D1%8B+%D0%B1%D0%B5%D1%81%D0%BF%D0%BB%D0%B0%D1%82%D0%BD%D0%BE%2C+%D0%BB%D0%B8%D1%88%D1%8C+%D0%B1%D1%8B+%D0%B8%D0%BC%D1%8F+%D0%BE%D1%81%D1%82%D0%B0%D0%BB%D0%BE%D1%81%D1%8C%C2%BB.+%D0%A0%D0%BE%D1%81%D1%81%D0%B8%D0%B9%D1%81%D0%BA%D0%B8%D0%B9+%D0%B0%D1%81%D1%82%D1%80%D0%BE%D0%BD%D0%BE%D0%BC+%D0%93%D0%B5%D0%BD%D0%BD%D0%B0%D0%B4%D0%B8%D0%B9+%D0%91%D0%BE%D1%80%D0%B8%D1%81%D0%BE%D0%B2+%D0%BE+%D0%BF%D0%B5%D1%80%D0%B2%D0%BE%D0%B9+%D0%B2+%D0%B8%D1%81%D1%82%D0%BE%D1%80%D0%B8%D0%B8+%D1%87%D0%B5%D0%BB%D0%BE%D0%B2%D0%B5%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%B0+%D0%BC%D0%B5%D0%B6%D0%B7%D0%B2%D1%91%D0%B7%D0%B4%D0%BD%D0%BE%D0%B9+%D0%BA%D0%BE%D0%BC%D0%B5%D1%82%D0%B5&rft.date=2019-09-13&rft.aulast=%D0%9D%D0%B5%D0%BB%D1%8E%D0%B1%D0%B8%D0%BD&rft.aufirst=%D0%9D%D0%B8%D0%BA%D0%BE%D0%BB%D0%B0%D0%B9&rft_id=https%3A%2F%2Fwww.fontanka.ru%2F2019%2F09%2F13%2F052%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Gray-prec-50"><span class="mw-cite-backlink"><b><a href="#cite_ref-Gray-prec_50-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGray" class="citation web cs1">Gray, Bill. <a rel="nofollow" class="external text" href="https://projectpluto.com/temp/gb_prec.htm#eph">"Pseudo-MPEC for gb00234 (precovery-eph)"</a>. <i>Project Pluto</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20190912141149/https://projectpluto.com/temp/gb_prec.htm">Archived</a> from the original on 12 September 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">11 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Project+Pluto&rft.atitle=Pseudo-MPEC+for+gb00234+%28precovery-eph%29&rft.aulast=Gray&rft.aufirst=Bill&rft_id=https%3A%2F%2Fprojectpluto.com%2Ftemp%2Fgb_prec.htm%23eph&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-RIA-51"><span class="mw-cite-backlink"><b><a href="#cite_ref-RIA_51-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation news cs1 cs1-prop-script cs1-prop-foreign-lang-source"><a rel="nofollow" class="external text" href="https://ria.ru/20190916/1558728005.html"><bdi lang="ru">Крымский астроном заявил, что открытая им комета изменит название</bdi></a> [Crimean astronomer says that the comet discovered by him will be renamed.]. <i><a href="/wiki/RIA_Novosti" title="RIA Novosti">RIA Novosti</a></i> <bdi lang="ru">РИА Новости</bdi> (in Russian). 16 September 2019. para. 5<span class="reference-accessdate">. Retrieved <span class="nowrap">16 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=RIA+Novosti&rft.atitle=%D0%9A%D1%80%D1%8B%D0%BC%D1%81%D0%BA%D0%B8%D0%B9+%D0%B0%D1%81%D1%82%D1%80%D0%BE%D0%BD%D0%BE%D0%BC+%D0%B7%D0%B0%D1%8F%D0%B2%D0%B8%D0%BB%2C+%D1%87%D1%82%D0%BE+%D0%BE%D1%82%D0%BA%D1%80%D1%8B%D1%82%D0%B0%D1%8F+%D0%B8%D0%BC+%D0%BA%D0%BE%D0%BC%D0%B5%D1%82%D0%B0+%D0%B8%D0%B7%D0%BC%D0%B5%D0%BD%D0%B8%D1%82+%D0%BD%D0%B0%D0%B7%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5&rft.pages=para.-5&rft.date=2019-09-16&rft_id=https%3A%2F%2Fria.ru%2F20190916%2F1558728005.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-archive-is-52"><span class="mw-cite-backlink"><b><a href="#cite_ref-archive-is_52-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190908144030/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"81 obs / 225 hours"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 8 September 2019.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=81+obs+%2F+225+hours&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span><br /> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190910180156/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"99 obs / 272 hours"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 10 September 2019.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=99+obs+%2F+272+hours&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span><br /> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190911040521/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"127 obs / 289 hours"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 11 September 2019.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=127+obs+%2F+289+hours&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span><br /> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190911120905/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"142 obs / 298 hours"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 11 September 2019.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=142+obs+%2F+298+hours&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span><br /> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190911213623/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"151 obs / 302 hours"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 11 September 2019.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=151+obs+%2F+302+hours&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-53"><span class="mw-cite-backlink"><b><a href="#cite_ref-53">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.worldtimeserver.com/current_time_in_RU-RC.aspx">"Current local time in Crimea, Republic of, Russia"</a>. <i>WorldTimeServer.com</i>. 23 May 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">15 August</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=WorldTimeServer.com&rft.atitle=Current+local+time+in+Crimea%2C+Republic+of%2C+Russia&rft.date=2016-05-23&rft_id=https%3A%2F%2Fwww.worldtimeserver.com%2Fcurrent_time_in_RU-RC.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-55"><span class="mw-cite-backlink"><b><a href="#cite_ref-55">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://minorplanetcenter.net/mpc/summary">"IAU Minor Planet Center"</a>. <i>minorplanetcenter.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">15 August</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=minorplanetcenter.net&rft.atitle=IAU+Minor+Planet+Center&rft_id=https%3A%2F%2Fminorplanetcenter.net%2Fmpc%2Fsummary&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-57"><span class="mw-cite-backlink"><b><a href="#cite_ref-57">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://minorplanetcenter.net//iau/NEO/PossNEO.html">"Neo Rating"</a>. <i>minorplanetcenter.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">15 August</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=minorplanetcenter.net&rft.atitle=Neo+Rating&rft_id=https%3A%2F%2Fminorplanetcenter.net%2F%2Fiau%2FNEO%2FPossNEO.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-59"><span class="mw-cite-backlink"><b><a href="#cite_ref-59">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.minorplanetcenter.net/iau/NEO/toconfirm_tabular.html">"The NEO Confirmation Page"</a>. <i>www.minorplanetcenter.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">15 August</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.minorplanetcenter.net&rft.atitle=The+NEO+Confirmation+Page&rft_id=https%3A%2F%2Fwww.minorplanetcenter.net%2Fiau%2FNEO%2Ftoconfirm_tabular.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Scout-61"><span class="mw-cite-backlink"><b><a href="#cite_ref-Scout_61-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190910140108/https://cneos.jpl.nasa.gov/scout/#/object/gb00234">"with 151 obs"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/#/object/gb00234">the original</a> on 10 September 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">10 September</span> 2019</span> – via archive.org.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=with+151+obs&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%23%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span><br /> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://archive.today/20190911213623/https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">"alternate CENOS archival source"</a>. <i>JPL CNEOS</i>. Scout: gb00234. Archived from <a rel="nofollow" class="external text" href="https://cneos.jpl.nasa.gov/scout/%23/object/gb00234">the original</a> on 11 September 2019 – via archive.today.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=JPL+CNEOS&rft.atitle=alternate+CENOS+archival+source&rft_id=https%3A%2F%2Fcneos.jpl.nasa.gov%2Fscout%2F%2523%2Fobject%2Fgb00234&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Gray35237-62"><span class="mw-cite-backlink"><b><a href="#cite_ref-Gray35237_62-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGray2019" class="citation web cs1">Gray, Bill (10 September 2019). <a rel="nofollow" class="external text" href="https://archive.today/20190919073304/https://groups.yahoo.com/neo/groups/mpml/conversations/messages/35237">"Is gb00234 an interstellar comet or asteroid?"</a>. Minor Planet Mailing List. Archived from <a rel="nofollow" class="external text" href="https://groups.yahoo.com/neo/groups/mpml/conversations/messages/35237">the original</a> on 19 September 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">10 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Is+gb00234+an+interstellar+comet+or+asteroid%3F&rft.pub=Minor+Planet+Mailing+List&rft.date=2019-09-10&rft.aulast=Gray&rft.aufirst=Bill&rft_id=https%3A%2F%2Fgroups.yahoo.com%2Fneo%2Fgroups%2Fmpml%2Fconversations%2Fmessages%2F35237&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Gray234c-63"><span class="mw-cite-backlink"><b><a href="#cite_ref-Gray234c_63-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGray" class="citation web cs1">Gray, Bill. <a rel="nofollow" class="external text" href="https://www.projectpluto.com/temp/gb00234c.htm#elements">"Pseudo-MPEC for gb00234 (non-grav A1+A2)"</a>. <i>Project Pluto</i>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20190911192042/https://www.projectpluto.com/temp/gb00234c.htm">Archived</a> from the original on 11 September 2019<span class="reference-accessdate">. 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Retrieved <span class="nowrap">2 October</span> 2019</span>. <q>On Dec. 7, the extrasolar comet now known as 2I/Borisov will make its closest approach to the sun.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=An+interstellar+comet%2C+in+time+for+the+holidays&rft.date=2019-10-01&rft.aulast=Overbye&rft.aufirst=Dennis&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2019%2F10%2F01%2Fscience%2Finterstellar-comet-astronomy-borisov.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-Hubble100719-65"><span class="mw-cite-backlink"><b><a href="#cite_ref-Hubble100719_65-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation report cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20191105193414/http://www.stsci.edu/ftp/observing/weekly_timeline/timeline_10_07_19">HST Weekly Observing Timeline</a> (Report). 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"Sending a spacecraft to interstellar comet C/2019 Q4 (Borisov)". <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/1909.06348">1909.06348</a></span> [<a rel="nofollow" class="external text" href="https://arxiv.org/archive/astro-ph.EP">astro-ph.EP</a>].</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=preprint&rft.jtitle=arXiv&rft.atitle=Sending+a+spacecraft+to+interstellar+comet+C%2F2019+Q4+%28Borisov%29&rft.date=2019-09-13&rft_id=info%3Aarxiv%2F1909.06348&rft.aulast=Hibberd&rft.aufirst=Adam&rft.au=Perakis%2C+Nikolaos&rft.au=Hein%2C+Andreas+M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> <li id="cite_note-US-Congress-20130410-91"><span class="mw-cite-backlink"><b><a href="#cite_ref-US-Congress-20130410_91-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation report cs1 cs1-prop-long-vol"><a rel="nofollow" class="external text" href="https://www.gpo.gov/fdsys/pkg/CHRG-113hhrg80552/pdf/CHRG-113hhrg80552.pdf">Threats from Space: A review of U.S. Government efforts to track and mitigate asteroids and meteors</a> <span class="cs1-format">(PDF)</span>. Committee on Science, Space, and Technology (Report). Vol. (Part I and Part II). House of Representatives, One Hundred Thirteenth Congress, First Session. 19 March 2013. p. 147<span class="reference-accessdate">. Retrieved <span class="nowrap">14 September</span> 2019</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=report&rft.btitle=Threats+from+Space%3A+A+review+of+U.S.+Government+efforts+to+track+and+mitigate+asteroids+and+meteors&rft.pages=147&rft.pub=House+of+Representatives%2C+One+Hundred+Thirteenth+Congress%2C+First+Session&rft.date=2013-03-19&rft_id=http%3A%2F%2Fwww.gpo.gov%2Ffdsys%2Fpkg%2FCHRG-113hhrg80552%2Fpdf%2FCHRG-113hhrg80552.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3A2I%2FBorisov" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=2I/Borisov&action=edit&section=16" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style 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srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:2I/Borisov" class="extiw" title="commons:Category:2I/Borisov">2I/Borisov</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639">2I/Borisov</a> at the <i><a href="/wiki/JPL_Small-Body_Database" title="JPL Small-Body Database">JPL Small-Body Database</a></i><ul class="noprint"><li><a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639&view=C">Close approach</a> <b>·</b> <a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639&view=D">Discovery</a> <b>·</b> <a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=1003639">Ephemeris</a> <b>·</b> <a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639&view=V">Orbit viewer</a> <b>·</b> <a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639&view=O">Orbit parameters</a> <b>·</b> <a rel="nofollow" class="external text" href="https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1003639&view=P">Physical parameters</a></li></ul></li> <li><a rel="nofollow" class="external text" href="https://news.yale.edu/sites/default/files/styles/featured_media/public/comet-side-by-side.jpg?itok=SqC8WoFN&c=07307e7d6a991172b9f808eb83b18804">Image of 2I/Borisov</a> – <a rel="nofollow" class="external text" href="https://news.yale.edu/2019/11/26/new-image-offers-close-view-interstellar-comet">comet is "14 times the size of Earth"</a> (<a href="/wiki/Yale_University" title="Yale University">Yale University</a>; November 2019)</li> <li><a rel="nofollow" class="external text" href="https://www.gemini.edu/node/21240">Image of 2I/Borisov</a> from the <a href="/wiki/Gemini_Observatory" title="Gemini Observatory">Gemini Observatory</a>, Hawaii</li> <li><a rel="nofollow" class="external text" href="http://lesia.obspm.fr/comets/lib/display-all-pict.php?Code=CK19Q040&Username=&CodeObs=&Config=&y1=2019&m1=08&y2=2021&m2=10&typ=pict">Pictures of 2I/Borisov</a> from <a href="/wiki/Paris_Observatory#Meudon" title="Paris Observatory">Paris Observatory (LESIA)</a></li> <li><a rel="nofollow" class="external text" href="https://in-space.ru/wp-content/uploads/2019/09/gb00234.gif">Discovery animation</a></li> <li><a rel="nofollow" class="external text" href="https://projectpluto.com/temp/2i.htm">FAQ</a> at ProjectPluto (Bill Gray)</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190918205957/http://exoplanet.eu/catalog/2i/borisov/">Extrasolar Planetary Encyclopedia</a> – 2I/Borisov</li> <li><a rel="nofollow" class="external text" href="http://orbitsimulator.com/gravitySimulatorCloud/simulations/1568147419153_gb00234.html">Hyperbolic orbit simulation</a> – 2I/Borisov (Tony Dunn)</li> <li><a rel="nofollow" class="external text" href="https://minorplanetcenter.net/mpec/K19/K19TB6.html">Minor Planet Center</a> MPEC 2019-T116 : COMET 2I/Borisov</li> <li><a rel="nofollow" class="external text" href="http://aerith.net/comet/catalog/0002I/mag.gif">Magnitude plot</a> by Seiichi Yoshida @ aerith.net (with predicted brightness)</li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=C1IVdfFSPww"><span class="plainlinks">Video (31:13) – 2I/Borisov talk</span></a> on <a href="/wiki/YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a> (MBusch/<a href="/wiki/Seth_Shostak" title="Seth Shostak">SShostak</a>) – <a href="/wiki/SETI" class="mw-redirect" title="SETI">SETI</a> (19 September 2019)</li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=NNOb3xrjOhE"><span class="plainlinks">Video (02:07) – 2I/Borisov chemical composition</span></a> on <a href="/wiki/YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a> – <a href="/wiki/NASA" title="NASA">NASA</a> (20 April 2020)</li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=vqMJo3DHOfg"><span class="plainlinks">Video (01:00) – 2I/Borisov orbit animations</span></a> on <a href="/wiki/YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a></li> <li><a rel="nofollow" class="external text" href="https://gravitysimulator.org/solar-system/interstellar-comet-borisov">Interactive 3D gravity simulation of Borisov's Solar System flyby</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · 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title="Template:2018 in space">2018</a></div> <div style="float: right;"><a href="/wiki/Template:2020_in_space" title="Template:2020 in space">2020</a> »</div></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/2019_in_spaceflight" title="2019 in spaceflight">Space probe<br />launches</a> <span typeof="mw:File"><a href="/wiki/Category:Space_probes_launched_in_2019" title="Category:Space probes launched in 2019"><img alt="Space probes launched in 2019" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png" decoding="async" width="15" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/30px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Beresheet" title="Beresheet">Beresheet</a> (lunar lander; Feb 2019)</li> <li><a href="/wiki/LightSail#LightSail_2" title="LightSail">LightSail 2</a> (solar sail demonstration; Jun 2019)</li> <li><a href="/wiki/Chandrayaan-2" title="Chandrayaan-2">Chandrayaan-2</a> / <a href="/wiki/Chandrayaan-2#Vikram_lander" title="Chandrayaan-2">Vikram</a> / <a href="/wiki/Pragyan_(Chandrayaan-2)" title="Pragyan (Chandrayaan-2)">Pragyan</a> (lunar obiter, lander and rover; Jul 2019)</li></ul> </div></td><td class="noviewer navbox-image" rowspan="7" style="width:1px;padding:0 0 0 2px;padding-left: 0.5em;"><div><span typeof="mw:File"><a href="/wiki/File:UltimaThule_CA06_color_20190516.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/60/UltimaThule_CA06_color_20190516.png/150px-UltimaThule_CA06_color_20190516.png" decoding="async" width="150" height="105" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/60/UltimaThule_CA06_color_20190516.png/225px-UltimaThule_CA06_color_20190516.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/60/UltimaThule_CA06_color_20190516.png/300px-UltimaThule_CA06_color_20190516.png 2x" data-file-width="1860" data-file-height="1302" /></a></span><br /><span typeof="mw:File"><a href="/wiki/File:Black_hole_-_Messier_87.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Black_hole_-_Messier_87.jpg/150px-Black_hole_-_Messier_87.jpg" decoding="async" width="150" height="87" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Black_hole_-_Messier_87.jpg/225px-Black_hole_-_Messier_87.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Black_hole_-_Messier_87.jpg/300px-Black_hole_-_Messier_87.jpg 2x" data-file-width="7416" data-file-height="4320" /></a></span><br /><span typeof="mw:File"><a href="/wiki/File:Esa-hubble-k2-18a_impression.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/8d/Esa-hubble-k2-18a_impression.jpg/150px-Esa-hubble-k2-18a_impression.jpg" decoding="async" width="150" height="88" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/8d/Esa-hubble-k2-18a_impression.jpg/225px-Esa-hubble-k2-18a_impression.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/8d/Esa-hubble-k2-18a_impression.jpg/300px-Esa-hubble-k2-18a_impression.jpg 2x" data-file-width="6000" data-file-height="3500" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Impact_event" title="Impact event">Impact events</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Kamchatka_meteor" title="Kamchatka meteor">Kamchatka meteor</a> (announced)</li> <li><a href="/wiki/2019_MO" title="2019 MO">2019 MO</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Selected <a href="/wiki/Near-Earth_object" title="Near-Earth object">NEOs</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_asteroid_close_approaches_to_Earth_in_2019" title="List of asteroid close approaches to Earth in 2019">Asteroid close approaches</a></li> <li><span class="nowrap"><a href="/wiki/2018_XB4" title="2018 XB4">2018 XB<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">4</span></span></a></span></li> <li><span class="nowrap"><a href="/wiki/2019_AS5" title="2019 AS5">2019 AS<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">5</span></span></a></span></li> <li><span class="nowrap"><a href="/wiki/2016_AZ8" title="2016 AZ8">2016 AZ<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">8</span></span></a></span></li> <li><a href="/wiki/66391_Moshup" title="66391 Moshup">66391 Moshup</a></li> <li><a href="/wiki/2019_OK" title="2019 OK">2019 OK</a></li> <li><a href="/wiki/1620_Geographos" title="1620 Geographos">1620 Geographos</a></li> <li><span class="nowrap"><a href="/wiki/2006_QV89" title="2006 QV89">2006 QV<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">89</span></span></a></span></li> <li><a href="/wiki/2100_Ra-Shalom" title="2100 Ra-Shalom">2100 Ra-Shalom</a></li> <li><span class="nowrap"><a href="/wiki/2019_SU3" title="2019 SU3">2019 SU<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">3</span></span></a></span></li> <li><span class="nowrap"><a href="/wiki/2019_TA7" title="2019 TA7">2019 TA<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">7</span></span></a></span></li> <li><span class="nowrap"><a href="/wiki/2019_UN13" title="2019 UN13">2019 UN<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">13</span></span></a></span></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_exoplanets_discovered_in_2019" title="List of exoplanets discovered in 2019">Exoplanets</a> <span typeof="mw:File"><a href="/wiki/Category:Exoplanets_discovered_in_2019" title="Category:Exoplanets discovered in 2019"><img alt="Exoplanets discovered in 2019" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png" decoding="async" width="15" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/30px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/AD_Leonis" title="AD Leonis">AD Leonis</a> b</li> <li><a href="/wiki/Beta_Pictoris_c" title="Beta Pictoris c">Beta Pictoris c</a></li> <li><a href="/wiki/DS_Tucanae" title="DS Tucanae">DS Tucanae</a> b</li> <li><a href="/wiki/Gliese_251" title="Gliese 251">Gliese 251</a> c</li> <li><a href="/wiki/Gliese_357_d" title="Gliese 357 d">Gliese 357 d</a></li> <li><a href="/wiki/Gliese_588" title="Gliese 588">Gliese 588</a> <ul><li>b</li> <li>c</li></ul></li> <li><a href="/wiki/Gliese_687" title="Gliese 687">Gliese 687</a> c</li> <li><a href="/wiki/Gliese_555" class="mw-redirect" title="Gliese 555">Gliese 555</a> b</li> <li><a href="/wiki/Gliese_754" title="Gliese 754">Gliese 754</a> b</li> <li><a href="/wiki/Gliese_784" title="Gliese 784">Gliese 784</a> b</li> <li><a href="/wiki/HR_5183_b" title="HR 5183 b">HR 5183 b</a></li> <li><a href="/wiki/Kepler-47d" class="mw-redirect" title="Kepler-47d">Kepler-47d</a> confirmed</li> <li><a href="/wiki/K2-288Bb" title="K2-288Bb">K2-288Bb</a></li> <li><a href="/wiki/L_1159-16" class="mw-redirect" title="L 1159-16">L 1159-16</a> <ul><li>b</li> <li>c</li> <li>d</li></ul></li> <li><a href="/wiki/LP_816-60" title="LP 816-60">LP 816-60</a> b</li> <li><a href="/wiki/LTT_1445" title="LTT 1445">LTT 1445</a> Ab</li> <li><a href="/wiki/Luyten%27s_Star" title="Luyten's Star">Luyten's Star</a> <ul><li>d</li> <li>e</li></ul></li> <li><a href="/wiki/PDS_70" title="PDS 70">PDS 70c</a></li> <li><a href="/wiki/Proxima_Centauri_c" title="Proxima Centauri c">Proxima Centauri c</a></li> <li><a href="/wiki/Struve_2398" title="Struve 2398">Struve 2398</a> <ul><li>Bb</li> <li>Bc</li></ul></li> <li><a href="/wiki/Tau_Ceti" title="Tau Ceti">Tau Ceti</a> i (hypothesized)</li> <li><a href="/wiki/Teegarden%27s_Star" title="Teegarden's Star">Teegarden's Star</a> <ul><li><a href="/wiki/Teegarden%27s_Star_b" title="Teegarden's Star b">b</a></li> <li><a href="/wiki/Teegarden%27s_Star_c" title="Teegarden's Star c">c</a></li></ul></li> <li><a href="/wiki/V1298_Tauri" title="V1298 Tauri">V1298 Tauri</a> <ul><li>b</li> <li>c</li> <li>d</li> <li>e</li></ul></li> <li><a href="/wiki/Wolf_359" title="Wolf 359">Wolf 359</a> <ul><li>b</li> <li>c</li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Discoveries</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><span class="nowrap"><a href="/wiki/2019_AQ3" title="2019 AQ3">2019 AQ<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">3</span></span></a></span></li> <li><a href="/wiki/ASASSN-19bt" title="ASASSN-19bt">ASASSN-19bt</a></li> <li><a href="/wiki/AT2019qiz" title="AT2019qiz">AT2019qiz</a></li> <li><a href="/wiki/GRB_190114C" title="GRB 190114C">GRB 190114C</a></li> <li><a href="/wiki/EPIC_204376071" title="EPIC 204376071">EPIC 204376071</a></li> <li><a href="/wiki/GW190412" title="GW190412">GW190412</a></li> <li><a href="/wiki/GW190521g" class="mw-redirect" title="GW190521g">GW190521g</a> (first-ever light from bh-bh merger)</li> <li><a href="/wiki/GW190814" title="GW190814">GW190814</a> (first-ever "mass-gap" collision)</li> <li><a href="/wiki/J043947.08%2B163415.7" class="mw-redirect" title="J043947.08+163415.7">J043947.08+163415.7</a></li> <li><a href="/wiki/K2-18b" title="K2-18b">K2-18b</a> water vapor</li> <li><a href="/wiki/Messier_87#Supermassive_black_hole_M87*" title="Messier 87">M87*</a> imaged</li> <li><a href="/w/index.php?title=PSR_J0030%2B0451&action=edit&redlink=1" class="new" title="PSR J0030+0451 (page does not exist)">PSR J0030+0451</a> mapped</li> <li><a href="/wiki/PSR_J0740%2B6620" title="PSR J0740+6620">PSR J0740+6620</a></li> <li><a href="/wiki/S5-HVS1" title="S5-HVS1">S5-HVS1</a></li> <li><a class="mw-selflink selflink">2I/Borisov</a></li> <li>20 <a href="/wiki/Moons_of_Saturn" title="Moons of Saturn">moons of Saturn</a></li> <li><a href="/wiki/WD_0145%2B234" title="WD 0145+234">WD 0145+234</a> detection of <a href="/wiki/Exoasteroid" title="Exoasteroid">exoasteroid</a> disruption</li> <li><a href="/wiki/WD_J0914%2B1914" title="WD J0914+1914">WD J0914+1914</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Comets <span typeof="mw:File"><a href="/wiki/Category:Comets_in_2019" title="Category:Comets in 2019"><img alt="Comets in 2019" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/15px-Symbol_category_class.svg.png" decoding="async" width="15" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/30px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></a></span></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/C/2018_Y1_(Iwamoto)" title="C/2018 Y1 (Iwamoto)">C/2018 Y1 (Iwamoto)</a></li> <li><a href="/wiki/78P/Gehrels" title="78P/Gehrels">78P/Gehrels</a></li> <li><a href="/wiki/168P/Hergenrother" title="168P/Hergenrother">168P/Hergenrother</a></li> <li><a href="/wiki/163P/NEAT" title="163P/NEAT">163P/NEAT</a></li> <li><a href="/wiki/138P/Shoemaker%E2%80%93Levy" title="138P/Shoemaker–Levy">138P/Shoemaker–Levy</a></li> <li><a href="/wiki/171P/Spahr" title="171P/Spahr">171P/Spahr</a></li> <li><a href="/wiki/289P/Blanpain" title="289P/Blanpain">289P/Blanpain</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Space exploration</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/New_Horizons" title="New Horizons">New Horizons</a></i> (encounter with <a href="/wiki/486958_Arrokoth" title="486958 Arrokoth">486958 Arrokoth</a>; Dec 2018 / Jan 2019)</li> <li><i><a href="/wiki/Chang%27e_4" title="Chang'e 4">Chang'e 4</a></i> / <i><a href="/wiki/Yutu-2" title="Yutu-2">Yutu-2</a></i> (landing on the <a href="/wiki/Far_side_of_the_Moon" title="Far side of the Moon">far side of the Moon</a>; Jan 2019)</li> <li><i><a href="/wiki/Opportunity_(rover)" title="Opportunity (rover)">Opportunity</a></i> (end of mission; Aug 2018 / Feb 2019)</li> <li><i><a href="/wiki/Hayabusa2" title="Hayabusa2">Hayabusa2</a></i> (departure from <a href="/wiki/162173_Ryugu" title="162173 Ryugu">162173 Ryugu</a>; Dec 2019)</li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="3"><div> <ul><li><span class="nowrap"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/32px-Earth-moon.jpg" decoding="async" width="32" height="26" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/48px-Earth-moon.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/64px-Earth-moon.jpg 2x" data-file-width="3000" data-file-height="2400" /></span></span> </span><a href="/wiki/Portal:Outer_space" title="Portal:Outer space">Outer space portal</a></li> <li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:2018_in_outer_space" title="Category:2018 in outer space">Category:2018 in outer space</a> — <b><a href="/wiki/Category:2019_in_outer_space" title="Category:2019 in outer space">Category:2019 in outer space</a></b> — <a href="/wiki/Category:2020_in_outer_space" title="Category:2020 in outer space">Category:2020 in outer space</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Comets" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2" style="text-align: center;"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Comets" title="Template:Comets"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Comets" title="Template talk:Comets"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Comets" title="Special:EditPage/Template:Comets"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Comets" style="font-size:114%;margin:0 4em"><a href="/wiki/Comet" title="Comet">Comets</a></div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Features</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Comet_nucleus" title="Comet nucleus">Nucleus</a></li> <li><a href="/wiki/Coma_(cometary)" class="mw-redirect" title="Coma (cometary)">Coma</a></li> <li><a href="/wiki/Comet_tail" title="Comet tail">Tails</a></li> <li><a href="/wiki/Antitail" class="mw-redirect" title="Antitail">Antitail</a></li> <li><a href="/wiki/Comet_dust" title="Comet dust">Comet dust</a></li> <li><a href="/wiki/Meteor_shower" title="Meteor shower">Meteor shower</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="6" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"><a href="/wiki/File:Hyakutake_Color.jpg" class="mw-file-description" title="Comet C/1996 B2 (Hyakutake)"><img alt="Comet C/1996 B2 (Hyakutake)" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Hyakutake_Color.jpg/100px-Hyakutake_Color.jpg" decoding="async" width="100" height="75" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Hyakutake_Color.jpg/150px-Hyakutake_Color.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Hyakutake_Color.jpg/200px-Hyakutake_Color.jpg 2x" data-file-width="1500" data-file-height="1125" /></a></span><br /><span typeof="mw:File"><a href="/wiki/File:67P_Churyumov-Gerasimenko_-_Rosetta_(32755885495).png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/bc/67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png/100px-67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png" decoding="async" width="100" height="100" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/bc/67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png/150px-67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/bc/67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png/200px-67P_Churyumov-Gerasimenko_-_Rosetta_%2832755885495%29.png 2x" data-file-width="3200" data-file-height="3200" /></a></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/Comet#Orbital_characteristics" title="Comet">Types</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_periodic_comets" title="List of periodic comets">Periodic</a> <ul><li><a href="/wiki/List_of_numbered_comets" title="List of numbered comets">Numbered</a></li> <li><a href="/wiki/Lost_comet" title="Lost comet">Lost</a></li> <li><a href="/wiki/List_of_long-period_comets" title="List of long-period comets">Long period</a></li> <li><a href="/wiki/List_of_Halley-type_comets" title="List of Halley-type comets">Halley-type</a></li> <li><a href="/wiki/Jupiter-family_comet" class="mw-redirect" title="Jupiter-family comet">Jupiter-family</a></li> <li><a href="/wiki/Category:Encke-type_comets" title="Category:Encke-type comets">Encke-type</a></li> <li><a href="/wiki/Active_asteroid" title="Active asteroid">Main-belt</a></li></ul></li> <li><a href="/wiki/List_of_non-periodic_comets" class="mw-redirect" title="List of non-periodic comets">Non-periodic</a> <ul><li><a href="/wiki/List_of_near-parabolic_comets" title="List of near-parabolic comets">Near-parabolic</a></li> <li><a href="/wiki/List_of_hyperbolic_comets" title="List of hyperbolic comets">Hyperbolic</a></li> <li><a href="/wiki/List_of_comets_with_no_meaningful_orbit" title="List of comets with no meaningful orbit">Unknown-orbit</a></li></ul></li> <li><a href="/wiki/Great_comet" title="Great comet">Great Comet</a></li> <li><a href="/wiki/Sungrazing_comet" title="Sungrazing comet">Sungrazing</a> (<a href="/wiki/Kreutz_sungrazer" title="Kreutz sungrazer">Kreutz</a>)</li> <li><a href="/wiki/Extinct_comet" title="Extinct comet">Extinct</a></li> <li><a href="/wiki/Exocomet" title="Exocomet">Exocomet</a></li> <li><a href="/wiki/Interstellar_object" title="Interstellar object">Interstellar</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Related</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Naming_of_comets" title="Naming of comets">Naming of comets</a></li> <li><a href="/wiki/Observational_history_of_comets" title="Observational history of comets">Observational history of comets</a></li> <li><a href="/wiki/Centaur_(minor_planet)#Similarities_to_comets" class="mw-redirect" title="Centaur (minor planet)">Centaur</a></li> <li><a href="/wiki/Category:Discoverers_of_comets" title="Category:Discoverers of comets">Comet discoverers</a> <ul><li><a href="/wiki/List_of_comets_discovered_by_the_LINEAR_project" title="List of comets discovered by the LINEAR project">LINEAR</a></li></ul></li> <li><a href="/wiki/Extraterrestrial_atmosphere" title="Extraterrestrial atmosphere">Extraterrestrial atmosphere</a></li> <li><a href="/wiki/Oort_cloud" title="Oort cloud">Oort cloud</a></li> <li><a href="/wiki/Small_Solar_System_body" title="Small Solar System body">Small Solar System body</a></li> <li><a href="/wiki/Asteroid" title="Asteroid">Asteroid</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Exploration</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_missions_to_comets" title="List of missions to comets">List of missions to comets</a></li> <li><a href="/wiki/List_of_comets_visited_by_spacecraft" class="mw-redirect" title="List of comets visited by spacecraft">List of comets visited by spacecraft</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Latest</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/C/2024_S1_(ATLAS)" title="C/2024 S1 (ATLAS)">C/2024 S1 (ATLAS)</a></li> <li><a href="/wiki/C/2023_P1_(Nishimura)" title="C/2023 P1 (Nishimura)">C/2023 P1 (Nishimura)</a></li> <li><a href="/wiki/C/2023_H2_(Lemmon)" title="C/2023 H2 (Lemmon)">C/2023 H2 (Lemmon)</a></li> <li><a href="/wiki/C/2023_E1_(ATLAS)" title="C/2023 E1 (ATLAS)">C/2023 E1 (ATLAS)</a></li> <li><a href="/wiki/C/2023_A3_(Tsuchinshan%E2%80%93ATLAS)" title="C/2023 A3 (Tsuchinshan–ATLAS)">C/2023 A3 (Tsuchinshan–ATLAS)</a></li> <li><a href="/wiki/C/2022_E3_(ZTF)" title="C/2022 E3 (ZTF)">C/2022 E3 (ZTF)</a></li> <li><a href="/wiki/C/2021_O3_(PanSTARRS)" title="C/2021 O3 (PanSTARRS)">C/2021 O3 (PanSTARRS)</a></li> <li><a href="/wiki/C/2021_J1_(Maury-Attard)" class="mw-redirect" title="C/2021 J1 (Maury-Attard)">C/2021 J1 (Maury-Attard)</a></li> <li><a href="/wiki/C/2021_A1_(Leonard)" title="C/2021 A1 (Leonard)">C/2021 A1 (Leonard)</a></li> <li><a href="/wiki/C/2020_F8_(SWAN)" title="C/2020 F8 (SWAN)">C/2020 F8 (SWAN)</a></li> <li><a href="/wiki/C/2020_F5_(MASTER)" title="C/2020 F5 (MASTER)">C/2020 F5 (MASTER)</a></li> <li><a href="/wiki/Comet_NEOWISE" title="Comet NEOWISE">C/2020 F3 (NEOWISE)</a></li> <li><a href="/wiki/C/2019_Y4_(ATLAS)" title="C/2019 Y4 (ATLAS)">C/2019 Y4 (ATLAS)</a></li> <li><a href="/wiki/C/2019_Y1_(ATLAS)" title="C/2019 Y1 (ATLAS)">C/2019 Y1 (ATLAS)</a></li> <li><a href="/wiki/C/2019_U6_(Lemmon)" title="C/2019 U6 (Lemmon)">C/2019 U6 (Lemmon)</a></li> <li><a class="mw-selflink selflink">2I/Borisov</a></li> <li><a href="/wiki/P/2019_LD2_(ATLAS)" title="P/2019 LD2 (ATLAS)">P/2019 LD2 (ATLAS)</a></li> <li><a href="/wiki/C/2018_Y1_(Iwamoto)" title="C/2018 Y1 (Iwamoto)">C/2018 Y1 (Iwamoto)</a></li> <li><a href="/wiki/C/2018_C2_(Lemmon)" title="C/2018 C2 (Lemmon)">C/2018 C2 (Lemmon)</a></li> <li><a href="/wiki/C/2017_U7" class="mw-redirect" title="C/2017 U7">C/2017 U7</a></li> <li><a href="/wiki/C/2017_K2_(PanSTARRS)" title="C/2017 K2 (PanSTARRS)">C/2017 K2 (PanSTARRS)</a></li> <li><a href="/wiki/C/2016_U1_(NEOWISE)" title="C/2016 U1 (NEOWISE)">C/2016 U1 (NEOWISE)</a></li> <li><a href="/wiki/C/2015_V2_(Johnson)" title="C/2015 V2 (Johnson)">C/2015 V2 (Johnson)</a></li> <li><a href="/wiki/C/2015_G2_(MASTER)" title="C/2015 G2 (MASTER)">C/2015 G2 (MASTER)</a></li> <li><a href="/wiki/C/2015_ER61_(PanSTARRS)" title="C/2015 ER61 (PanSTARRS)">C/2015 ER61 (PanSTARRS)</a></li> <li><a href="/wiki/C/2014_UN271_(Bernardinelli%E2%80%93Bernstein)" title="C/2014 UN271 (Bernardinelli–Bernstein)">C/2014 UN<sub>271</sub> (Bernardinelli–Bernstein)</a></li> <li><a href="/wiki/C/2014_Q2_(Lovejoy)" title="C/2014 Q2 (Lovejoy)">C/2014 Q2 (Lovejoy)</a></li> <li><a href="/wiki/C/2014_Q1_(PanSTARRS)" title="C/2014 Q1 (PanSTARRS)">C/2014 Q1 (PanSTARRS)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Culture and<br />speculation</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Antimatter_comet" title="Antimatter comet">Antimatter comet</a></li> <li><a href="/wiki/Comets_in_fiction" title="Comets in fiction">Comets in fiction</a></li> <li><a href="/wiki/Comet_vintages" title="Comet vintages">Comet vintages</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks mw-collapsible mw-collapsed navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="col" class="navbox-title" colspan="2" style="text-align: center;"><div id="Lists_of_comets_(more)" style="font-size:114%;margin:0 4em"><a href="/wiki/Lists_of_comets" title="Lists of comets">Lists of comets</a> (<a href="/wiki/Category:Lists_of_comets" title="Category:Lists of comets">more</a>)</div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/List_of_numbered_comets" title="List of numbered comets">Periodic<br />comets</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Until 1985<br />(all)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Halley%27s_Comet" title="Halley's Comet">1P/Halley</a></li> <li><a href="/wiki/Comet_Encke" title="Comet Encke">2P/Encke</a></li> <li><a href="/wiki/Biela%27s_Comet" title="Biela's Comet">3D/Biela</a></li> <li><a href="/wiki/4P/Faye" title="4P/Faye">4P/Faye</a></li> <li><a href="/wiki/5D/Brorsen" title="5D/Brorsen">5D/Brorsen</a></li> <li><a href="/wiki/6P/d%27Arrest" title="6P/d'Arrest">6P/d'Arrest</a></li> <li><a href="/wiki/7P/Pons%E2%80%93Winnecke" title="7P/Pons–Winnecke">7P/Pons–Winnecke</a></li> <li><a href="/wiki/8P/Tuttle" title="8P/Tuttle">8P/Tuttle</a></li> <li><a href="/wiki/Tempel_1" title="Tempel 1">9P/Tempel</a></li> <li><a href="/wiki/10P/Tempel" title="10P/Tempel">10P/Tempel</a></li> <li><a href="/wiki/11P/Tempel%E2%80%93Swift%E2%80%93LINEAR" title="11P/Tempel–Swift–LINEAR">11P/Tempel–Swift–LINEAR</a></li> <li><a href="/wiki/12P/Pons%E2%80%93Brooks" title="12P/Pons–Brooks">12P/Pons–Brooks</a></li> <li><a href="/wiki/13P/Olbers" title="13P/Olbers">13P/Olbers</a></li> <li><a href="/wiki/14P/Wolf" title="14P/Wolf">14P/Wolf</a></li> <li><a href="/wiki/15P/Finlay" title="15P/Finlay">15P/Finlay</a></li> <li><a href="/wiki/16P/Brooks" title="16P/Brooks">16P/Brooks</a></li> <li><a href="/wiki/Comet_Holmes" title="Comet Holmes">17P/Holmes</a></li> <li><a href="/wiki/18D/Perrine%E2%80%93Mrkos" title="18D/Perrine–Mrkos">18D/Perrine–Mrkos</a></li> <li><a href="/wiki/19P/Borrelly" title="19P/Borrelly">19P/Borrelly</a></li> <li><a href="/wiki/20D/Westphal" title="20D/Westphal">20D/Westphal</a></li> <li><a href="/wiki/21P/Giacobini%E2%80%93Zinner" title="21P/Giacobini–Zinner">21P/Giacobini–Zinner</a></li> <li><a href="/wiki/22P/Kopff" title="22P/Kopff">22P/Kopff</a></li> <li><a href="/wiki/23P/Brorsen%E2%80%93Metcalf" title="23P/Brorsen–Metcalf">23P/Brorsen–Metcalf</a></li> <li><a href="/wiki/24P/Schaumasse" title="24P/Schaumasse">24P/Schaumasse</a></li> <li><a href="/wiki/25D/Neujmin" title="25D/Neujmin">25D/Neujmin</a></li> <li><a href="/wiki/26P/Grigg%E2%80%93Skjellerup" title="26P/Grigg–Skjellerup">26P/Grigg–Skjellerup</a></li> <li><a href="/wiki/27P/Crommelin" title="27P/Crommelin">27P/Crommelin</a></li> <li><a href="/wiki/28P/Neujmin" title="28P/Neujmin">28P/Neujmin</a></li> <li><a href="/wiki/29P/Schwassmann%E2%80%93Wachmann" title="29P/Schwassmann–Wachmann">29P/Schwassmann–Wachmann</a></li> <li><a href="/wiki/30P/Reinmuth" title="30P/Reinmuth">30P/Reinmuth</a></li> <li><a href="/wiki/31P/Schwassmann%E2%80%93Wachmann" title="31P/Schwassmann–Wachmann">31P/Schwassmann–Wachmann</a></li> <li><a href="/wiki/32P/Comas_Sol%C3%A0" title="32P/Comas Solà">32P/Comas Solà</a></li> <li><a href="/wiki/33P/Daniel" title="33P/Daniel">33P/Daniel</a></li> <li><a href="/wiki/34D/Gale" title="34D/Gale">34D/Gale</a></li> <li><a href="/wiki/35P/Herschel%E2%80%93Rigollet" title="35P/Herschel–Rigollet">35P/Herschel–Rigollet</a></li> <li><a href="/wiki/36P/Whipple" title="36P/Whipple">36P/Whipple</a></li> <li><a href="/wiki/37P/Forbes" title="37P/Forbes">37P/Forbes</a></li> <li><a href="/wiki/38P/Stephan%E2%80%93Oterma" title="38P/Stephan–Oterma">38P/Stephan–Oterma</a></li> <li><a href="/wiki/39P/Oterma" title="39P/Oterma">39P/Oterma</a></li> <li><a href="/wiki/40P/V%C3%A4is%C3%A4l%C3%A4" title="40P/Väisälä">40P/Väisälä</a></li> <li><a href="/wiki/41P/Tuttle%E2%80%93Giacobini%E2%80%93Kres%C3%A1k" title="41P/Tuttle–Giacobini–Kresák">41P/Tuttle–Giacobini–Kresák</a></li> <li><a href="/wiki/42P/Neujmin" title="42P/Neujmin">42P/Neujmin</a></li> <li><a href="/wiki/43P/Wolf%E2%80%93Harrington" title="43P/Wolf–Harrington">43P/Wolf–Harrington</a></li> <li><a href="/wiki/44P/Reinmuth" title="44P/Reinmuth">44P/Reinmuth</a></li> <li><a href="/wiki/45P/Honda%E2%80%93Mrkos%E2%80%93Pajdu%C5%A1%C3%A1kov%C3%A1" title="45P/Honda–Mrkos–Pajdušáková">45P/Honda–Mrkos–Pajdušáková</a></li> <li><a href="/wiki/46P/Wirtanen" title="46P/Wirtanen">46P/Wirtanen</a></li> <li><a href="/wiki/47P/Ashbrook%E2%80%93Jackson" title="47P/Ashbrook–Jackson">47P/Ashbrook–Jackson</a></li> <li><a href="/wiki/48P/Johnson" title="48P/Johnson">48P/Johnson</a></li> <li><a href="/wiki/49P/Arend%E2%80%93Rigaux" title="49P/Arend–Rigaux">49P/Arend–Rigaux</a></li> <li><a href="/wiki/50P/Arend" title="50P/Arend">50P/Arend</a></li> <li><a href="/wiki/51P/Harrington" title="51P/Harrington">51P/Harrington</a></li> <li><a href="/wiki/52P/Harrington%E2%80%93Abell" title="52P/Harrington–Abell">52P/Harrington–Abell</a></li> <li><a href="/wiki/53P/Van_Biesbroeck" title="53P/Van Biesbroeck">53P/Van Biesbroeck</a></li> <li><a href="/wiki/54P/de_Vico%E2%80%93Swift%E2%80%93NEAT" title="54P/de Vico–Swift–NEAT">54P/de Vico–Swift–NEAT</a></li> <li><a href="/wiki/55P/Tempel%E2%80%93Tuttle" title="55P/Tempel–Tuttle">55P/Tempel–Tuttle</a></li> <li><a href="/wiki/56P/Slaughter%E2%80%93Burnham" title="56P/Slaughter–Burnham">56P/Slaughter–Burnham</a></li> <li><a href="/wiki/57P/du_Toit%E2%80%93Neujmin%E2%80%93Delporte" title="57P/du Toit–Neujmin–Delporte">57P/du Toit–Neujmin–Delporte</a></li> <li><a href="/wiki/58P/Jackson%E2%80%93Neujmin" title="58P/Jackson–Neujmin">58P/Jackson–Neujmin</a></li> <li><a href="/wiki/59P/Kearns%E2%80%93Kwee" title="59P/Kearns–Kwee">59P/Kearns–Kwee</a></li> <li><a href="/wiki/60P/Tsuchinshan" title="60P/Tsuchinshan">60P/Tsuchinshan</a></li> <li><a href="/wiki/61P/Shajn%E2%80%93Schaldach" title="61P/Shajn–Schaldach">61P/Shajn–Schaldach</a></li> <li><a href="/wiki/62P/Tsuchinshan" title="62P/Tsuchinshan">62P/Tsuchinshan</a></li> <li><a href="/wiki/63P/Wild" title="63P/Wild">63P/Wild</a></li> <li><a href="/wiki/64P/Swift%E2%80%93Gehrels" title="64P/Swift–Gehrels">64P/Swift–Gehrels</a></li> <li><a href="/wiki/65P/Gunn" title="65P/Gunn">65P/Gunn</a></li> <li><a href="/wiki/66P/du_Toit" title="66P/du Toit">66P/du Toit</a></li> <li><a href="/wiki/67P/Churyumov%E2%80%93Gerasimenko" title="67P/Churyumov–Gerasimenko">67P/Churyumov–Gerasimenko</a></li> <li><a href="/wiki/68P/Klemola" title="68P/Klemola">68P/Klemola</a></li> <li><a href="/wiki/69P/Taylor" title="69P/Taylor">69P/Taylor</a></li> <li><a href="/wiki/70P/Kojima" title="70P/Kojima">70P/Kojima</a></li> <li><a href="/wiki/71P/Clark" title="71P/Clark">71P/Clark</a></li> <li><a href="/wiki/72P/Denning%E2%80%93Fujikawa" title="72P/Denning–Fujikawa">72P/Denning–Fujikawa</a></li> <li><a href="/wiki/73P/Schwassmann%E2%80%93Wachmann" title="73P/Schwassmann–Wachmann">73P/Schwassmann–Wachmann</a></li> <li><a href="/wiki/74P/Smirnova%E2%80%93Chernykh" title="74P/Smirnova–Chernykh">74P/Smirnova–Chernykh</a></li> <li><a href="/wiki/75D/Kohoutek" title="75D/Kohoutek">75D/Kohoutek</a></li> <li><a href="/wiki/76P/West%E2%80%93Kohoutek%E2%80%93Ikemura" title="76P/West–Kohoutek–Ikemura">76P/West–Kohoutek–Ikemura</a></li> <li><a href="/wiki/77P/Longmore" title="77P/Longmore">77P/Longmore</a></li> <li><a href="/wiki/78P/Gehrels" title="78P/Gehrels">78P/Gehrels</a></li> <li><a href="/wiki/79P/du_Toit%E2%80%93Hartley" title="79P/du Toit–Hartley">79P/du Toit–Hartley</a></li> <li><a href="/wiki/80P/Peters%E2%80%93Hartley" title="80P/Peters–Hartley">80P/Peters–Hartley</a></li> <li><a href="/wiki/81P/Wild" title="81P/Wild">81P/Wild</a></li> <li><a href="/wiki/82P/Gehrels" title="82P/Gehrels">82P/Gehrels</a></li> <li><a href="/wiki/83D/Russell" title="83D/Russell">83D/Russell</a></li> <li><a href="/wiki/84P/Giclas" title="84P/Giclas">84P/Giclas</a></li> <li><a href="/wiki/85D/Boethin" title="85D/Boethin">85D/Boethin</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">After 1985<br />(notable)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/88P/Howell" title="88P/Howell">88P/Howell</a></li> <li><a href="/wiki/92P/Sanguin" title="92P/Sanguin">92P/Sanguin</a></li> <li><a href="/wiki/96P/Machholz" title="96P/Machholz">96P/Machholz</a></li> <li><a href="/wiki/97P/Metcalf%E2%80%93Brewington" title="97P/Metcalf–Brewington">97P/Metcalf–Brewington</a></li> <li><a href="/wiki/103P/Hartley" title="103P/Hartley">103P/Hartley</a></li> <li><a href="/wiki/4015_Wilson%E2%80%93Harrington" title="4015 Wilson–Harrington">107P/Wilson–Harrington</a></li> <li><a href="/wiki/108P/Ciffr%C3%A9o" title="108P/Ciffréo">108P/Ciffréo</a></li> <li><a href="/wiki/Comet_Swift%E2%80%93Tuttle" title="Comet Swift–Tuttle">109P/Swift–Tuttle</a></li> <li><a href="/wiki/122P/de_Vico" title="122P/de Vico">122P/de Vico</a></li> <li><a href="/wiki/126P/IRAS" title="126P/IRAS">126P/IRAS</a></li> <li><a href="/wiki/141P/Machholz" title="141P/Machholz">141P/Machholz</a></li> <li><a href="/wiki/144P/Kushida" title="144P/Kushida">144P/Kushida</a></li> <li><a href="/wiki/147P/Kushida%E2%80%93Muramatsu" title="147P/Kushida–Muramatsu">147P/Kushida–Muramatsu</a></li> <li><a href="/wiki/153P/Ikeya%E2%80%93Zhang" title="153P/Ikeya–Zhang">153P/Ikeya–Zhang</a></li> <li><a href="/wiki/156P/Russell%E2%80%93LINEAR" title="156P/Russell–LINEAR">156P/Russell–LINEAR</a></li> <li><a href="/wiki/161P/Hartley%E2%80%93IRAS" title="161P/Hartley–IRAS">161P/Hartley–IRAS</a></li> <li><a href="/wiki/162P/Siding_Spring" title="162P/Siding Spring">162P/Siding Spring</a></li> <li><a href="/wiki/168P/Hergenrother" title="168P/Hergenrother">168P/Hergenrother</a></li> <li><a href="/wiki/169P/NEAT" title="169P/NEAT">169P/NEAT</a></li> <li><a href="/wiki/177P/Barnard" title="177P/Barnard">177P/Barnard</a></li> <li><a href="/wiki/178P/Hug%E2%80%93Bell" title="178P/Hug–Bell">178P/Hug–Bell</a></li> <li><a href="/wiki/205P/Giacobini" title="205P/Giacobini">205P/Giacobini</a></li> <li><a href="/wiki/209P/LINEAR" title="209P/LINEAR">209P/LINEAR</a></li> <li><a href="/wiki/238P/Read" title="238P/Read">238P/Read</a></li> <li><a href="/wiki/246P/NEAT" title="246P/NEAT">246P/NEAT</a></li> <li><a href="/wiki/249P/LINEAR" title="249P/LINEAR">249P/LINEAR</a></li> <li><a href="/wiki/252P/LINEAR" title="252P/LINEAR">252P/LINEAR</a></li> <li><a href="/wiki/255P/Levy" title="255P/Levy">255P/Levy</a></li> <li><a href="/wiki/273P/Pons%E2%80%93Gambart" title="273P/Pons–Gambart">273P/Pons–Gambart</a></li> <li><a href="/wiki/289P/Blanpain" title="289P/Blanpain">289P/Blanpain</a></li> <li><a href="/wiki/311P/PanSTARRS" title="311P/PanSTARRS">311P/PanSTARRS</a></li> <li><a href="/wiki/322P/SOHO" title="322P/SOHO">322P/SOHO</a></li> <li><a href="/wiki/323P/SOHO" title="323P/SOHO">323P/SOHO</a></li> <li><a href="/wiki/332P/Ikeya%E2%80%93Murakami" title="332P/Ikeya–Murakami">332P/Ikeya–Murakami</a></li> <li><a href="/wiki/333P/LINEAR" title="333P/LINEAR">333P/LINEAR</a></li> <li><a href="/wiki/354P/LINEAR" title="354P/LINEAR">354P/LINEAR</a></li> <li><a href="/wiki/(457175)_2008_GO98" title="(457175) 2008 GO98">362P</a></li> <li><a href="/wiki/460P/PanSTARRS" title="460P/PanSTARRS">460P/PanSTARRS</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/Asteroid#Terminology" title="Asteroid">Comet-like<br />asteroids</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/596_Scheila" title="596 Scheila">596 Scheila</a></li> <li><a href="/wiki/2060_Chiron" title="2060 Chiron">2060 Chiron</a> (95P)</li> <li><a href="/wiki/4015_Wilson%E2%80%93Harrington" title="4015 Wilson–Harrington">4015 Wilson–Harrington</a> (107P)</li> <li><a href="/wiki/7968_Elst%E2%80%93Pizarro" title="7968 Elst–Pizarro">7968 Elst–Pizarro</a> (133P)</li> <li><a href="/wiki/165P/LINEAR" title="165P/LINEAR">165P/LINEAR</a></li> <li><a href="/wiki/166P/NEAT" title="166P/NEAT">166P/NEAT</a></li> <li><a href="/wiki/167P/CINEOS" title="167P/CINEOS">167P/CINEOS</a></li> <li><a href="/wiki/60558_Echeclus" title="60558 Echeclus">60558 Echeclus</a> (174P)</li> <li><a href="/wiki/118401_LINEAR" title="118401 LINEAR">118401 LINEAR</a> (176P)</li> <li><a href="/wiki/238P/Read" title="238P/Read">238P/Read</a></li> <li><a href="/wiki/259P/Garradd" title="259P/Garradd">259P/Garradd</a></li> <li><a href="/wiki/311P/PanSTARRS" title="311P/PanSTARRS">311P/PanSTARRS</a></li> <li><a href="/wiki/324P/La_Sagra" title="324P/La Sagra">324P/La Sagra</a></li> <li><a href="/wiki/331P/Gibbs" title="331P/Gibbs">331P/Gibbs</a></li> <li><a href="/wiki/354P/LINEAR" title="354P/LINEAR">354P/LINEAR</a></li> <li><a href="/wiki/358P/PANSTARRS" class="mw-redirect" title="358P/PANSTARRS">358P/PANSTARRS</a></li> <li><a href="/wiki/P/2013_R3_(Catalina-PANSTARRS)" class="mw-redirect" title="P/2013 R3 (Catalina-PANSTARRS)">P/2013 R3 (Catalina-PANSTARRS)</a></li> <li><a href="/wiki/(300163)_2006_VW139" title="(300163) 2006 VW139">(300163) 2006 VW139</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/Lost_comet" title="Lost comet">Lost</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Recovered</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/9P/Tempel" class="mw-redirect" title="9P/Tempel">9P/Tempel</a></li> <li><a href="/wiki/11P/Tempel%E2%80%93Swift%E2%80%93LINEAR" title="11P/Tempel–Swift–LINEAR">11P/Tempel–Swift–LINEAR</a></li> <li><a href="/wiki/15P/Finlay" title="15P/Finlay">15P/Finlay</a></li> <li><a href="/wiki/Comet_Holmes" title="Comet Holmes">17P/Holmes</a></li> <li><a href="/wiki/27P/Crommelin" title="27P/Crommelin">27P/Crommelin</a></li> <li><a href="/wiki/54P/de_Vico%E2%80%93Swift%E2%80%93NEAT" title="54P/de Vico–Swift–NEAT">54P/de Vico–Swift–NEAT</a></li> <li><a href="/wiki/55P/Tempel%E2%80%93Tuttle" title="55P/Tempel–Tuttle">55P/Tempel–Tuttle</a></li> <li><a href="/wiki/57P/du_Toit%E2%80%93Neujmin%E2%80%93Delporte" title="57P/du Toit–Neujmin–Delporte">57P/du Toit–Neujmin–Delporte</a></li> <li><a href="/wiki/69P/Taylor" title="69P/Taylor">69P/Taylor</a></li> <li><a href="/wiki/72P/Denning%E2%80%93Fujikawa" title="72P/Denning–Fujikawa">72P/Denning–Fujikawa</a></li> <li><a href="/wiki/80P/Peters%E2%80%93Hartley" title="80P/Peters–Hartley">80P/Peters–Hartley</a></li> <li><a href="/wiki/97P/Metcalf%E2%80%93Brewington" title="97P/Metcalf–Brewington">97P/Metcalf–Brewington</a></li> <li><a href="/wiki/4015_Wilson%E2%80%93Harrington" title="4015 Wilson–Harrington">107P/Wilson–Harrington</a></li> <li><a href="/wiki/113P/Spitaler" title="113P/Spitaler">113P/Spitaler</a></li> <li><a href="/wiki/122P/de_Vico" title="122P/de Vico">122P/de Vico</a></li> <li><a href="/wiki/157P/Tritton" title="157P/Tritton">157P/Tritton</a></li> <li><a href="/wiki/205P/Giacobini" title="205P/Giacobini">205P/Giacobini</a></li> <li><a href="/wiki/206P/Barnard%E2%80%93Boattini" title="206P/Barnard–Boattini">206P/Barnard–Boattini</a></li> <li><a href="/wiki/226P/Pigott%E2%80%93LINEAR%E2%80%93Kowalski" title="226P/Pigott–LINEAR–Kowalski">226P/Pigott–LINEAR–Kowalski</a></li> <li><a href="/wiki/271P/van_Houten%E2%80%93Lemmon" title="271P/van Houten–Lemmon">271P/van Houten–Lemmon</a></li> <li><a href="/wiki/289P/Blanpain" title="289P/Blanpain">289P/Blanpain</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Destroyed</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Biela%27s_Comet" title="Biela's Comet">3D/Biela</a></li> <li><a href="/wiki/Comet_Shoemaker%E2%80%93Levy_9" title="Comet Shoemaker–Levy 9">D/1993 F2 (Shoemaker–Levy 9)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Not found</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lexell%27s_Comet" title="Lexell's Comet">D/1770 L1 (Lexell)</a></li> <li><a href="/wiki/5D/Brorsen" title="5D/Brorsen">5D/Brorsen</a></li> <li><a href="/wiki/18D/Perrine%E2%80%93Mrkos" title="18D/Perrine–Mrkos">18D/Perrine–Mrkos</a></li> <li><a href="/wiki/20D/Westphal" title="20D/Westphal">20D/Westphal</a></li> <li><a href="/wiki/25D/Neujmin" title="25D/Neujmin">25D/Neujmin</a></li> <li><a href="/wiki/34D/Gale" title="34D/Gale">34D/Gale</a></li> <li><a href="/wiki/75D/Kohoutek" title="75D/Kohoutek">75D/Kohoutek</a></li> <li><a href="/wiki/83D/Russell" title="83D/Russell">83D/Russell</a></li> <li><a href="/wiki/85D/Boethin" title="85D/Boethin">85D/Boethin</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/List_of_minor_planets_and_comets_visited_by_spacecraft#List_of_comets_visited_by_spacecraft" title="List of minor planets and comets visited by spacecraft">Visited by<br />spacecraft</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/21P/Giacobini%E2%80%93Zinner" title="21P/Giacobini–Zinner">21P/Giacobini–Zinner</a> (1985)</li> <li><a href="/wiki/Halley%27s_Comet" title="Halley's Comet">1P/Halley</a> (1986)</li> <li><a href="/wiki/26P/Grigg%E2%80%93Skjellerup" title="26P/Grigg–Skjellerup">26P/Grigg–Skjellerup</a> (1992)</li> <li><a href="/wiki/19P/Borrelly" title="19P/Borrelly">19P/Borrelly</a> (2001)</li> <li><a href="/wiki/81P/Wild" title="81P/Wild">81P/Wild</a> (2004)</li> <li><a href="/wiki/Tempel_1" title="Tempel 1">9P/Tempel</a> (2005, 2011)</li> <li><a href="/wiki/Comet_McNaught" title="Comet McNaught">C/2006 P1</a> (2007)</li> <li><a href="/wiki/103P/Hartley" title="103P/Hartley">103P/Hartley</a> (2010)</li> <li><a href="/wiki/67P/Churyumov%E2%80%93Gerasimenko" title="67P/Churyumov–Gerasimenko">67P/Churyumov–Gerasimenko</a> (2014)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;"><a href="/wiki/List_of_near-parabolic_comets" title="List of near-parabolic comets">Near-Parabolic<br />comets<br />(notable)</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">Until 1990</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Caesar%27s_Comet" title="Caesar's Comet">C/-43 K1 (Caesar's Comet)</a></li> <li><a href="/wiki/X/1106_C1" title="X/1106 C1">X/1106 C1 (Great Comet of 1106)</a></li> <li><a href="/wiki/Great_Comet_of_1264" title="Great Comet of 1264">C/1264 N1 (Great Comet of 1264)</a></li> <li><a href="/wiki/Great_Comet_of_1402" title="Great Comet of 1402">C/1402 D1 (Great Comet of 1402)</a></li> <li><a href="/wiki/Great_Comet_of_1472" title="Great Comet of 1472">C/1471 Y1 (Great Comet of 1472)</a></li> <li><a href="/wiki/Great_Comet_of_1577" title="Great Comet of 1577">C/1577 V1 (Great Comet of 1577)</a></li> <li><a href="/wiki/C/1652_Y1" title="C/1652 Y1">C/1652 Y1</a></li> <li><a href="/wiki/Great_Comet_of_1680" title="Great Comet of 1680">C/1680 V1 (Great Comet of 1680, Kirsch's Comet, Newton's Comet)</a>)</li> <li><a href="/wiki/C/1702_H1" title="C/1702 H1">C/1702 H1 (Comet of 1702)</a></li> <li><a href="/wiki/Comet_of_1729" class="mw-redirect" title="Comet of 1729">C/1729 P1 (Comet of 1729, Comet Sarabat)</a></li> <li><a href="/wiki/Great_Comet_of_1744" title="Great Comet of 1744">C/1743 X1 (Great Comet of 1744, Comet Klinkenberg-Chéseaux)</a></li> <li><a href="/wiki/C/1760_A1" title="C/1760 A1">C/1760 A1 (Great Comet of 1760)</a></li> <li><a href="/wiki/C/1769_P1" class="mw-redirect" title="C/1769 P1">C/1769 P1 (Great Comet of 1769)</a></li> <li><a href="/wiki/C/1807_R1" title="C/1807 R1">C/1807 R1 (Great Comet of 1807)</a></li> <li><a href="/wiki/Great_Comet_of_1811" title="Great Comet of 1811">C/1811 F1 (Great Comet of 1811)</a></li> <li><a href="/wiki/Great_Comet_of_1819" title="Great Comet of 1819">C/1819 N1 (Great Comet of 1819)</a></li> <li><a href="/wiki/Great_Comet_of_1823" title="Great Comet of 1823">C/1823 Y1 (Great Comet of 1823)</a></li> <li><a href="/wiki/Great_Comet_of_1843" title="Great Comet of 1843">C/1843 D1 (Great March Comet of 1843)</a></li> <li><a href="/wiki/C/1847_T1" class="mw-redirect" title="C/1847 T1">C/1847 T1 (Miss Mitchell's Comet)</a></li> <li><a href="/wiki/Comet_Donati" title="Comet Donati">C/1858 L1 (Comet Donati)</a></li> <li><a href="/wiki/C/1861_G1_(Thatcher)" title="C/1861 G1 (Thatcher)">C/1861 G1 (Comet Thatcher)</a></li> <li><a href="/wiki/C/1861_J1" title="C/1861 J1">C/1861 J1 (Great Comet of 1861)</a></li> <li><a href="/wiki/C/1865_B1" title="C/1865 B1">C/1865 B1 (Great Southern Comet of 1865)</a></li> <li><a href="/wiki/X/1872_X1" title="X/1872 X1">X/1872 X1 (Pogson's Comet)</a></li> <li><a href="/wiki/C/1874_H1" class="mw-redirect" title="C/1874 H1">C/1874 H1 (Comet Coggia)</a></li> <li><a href="/wiki/C/1881_K1" class="mw-redirect" title="C/1881 K1">C/1881 K1 (Comet Tebbutt)</a></li> <li><a href="/wiki/Great_Comet_of_1882" title="Great Comet of 1882">C/1882 R1 (Great Comet of 1882)</a></li> <li><a href="/wiki/Great_Southern_Comet_of_1887" title="Great Southern Comet of 1887">C/1887 B1 (Great Southern Comet of 1887)</a></li> <li><a href="/wiki/Great_Comet_of_1901" title="Great Comet of 1901">C/1901 G1 (Great Comet of 1901)</a></li> <li><a href="/wiki/Great_January_Comet_of_1910" title="Great January Comet of 1910">C/1910 A1 (Great January Comet of 1910)</a></li> <li><a href="/wiki/C/1911_O1" class="mw-redirect" title="C/1911 O1">C/1911 O1 (Brooks)</a></li> <li><a href="/wiki/C/1911_S3" class="mw-redirect" title="C/1911 S3">C/1911 S3 (Beljawsky)</a></li> <li><a href="/wiki/Comet_Skjellerup%E2%80%93Maristany" title="Comet Skjellerup–Maristany">C/1927 X1 (Skjellerup–Maristany)</a></li> <li><a href="/wiki/C/1931_P1_(Ryves)" class="mw-redirect" title="C/1931 P1 (Ryves)">C/1931 P1 (Ryves)</a></li> <li><a href="/wiki/C/1941_B2_(de_Kock-Paraskevopoulos)" class="mw-redirect" title="C/1941 B2 (de Kock-Paraskevopoulos)">C/1941 B2 (de Kock-Paraskevopoulos)</a></li> <li><a href="/wiki/C/1947_X1_(Southern_Comet)" class="mw-redirect" title="C/1947 X1 (Southern Comet)">C/1947 X1 (Southern Comet)</a></li> <li><a href="/wiki/C/1948_V1" title="C/1948 V1">C/1948 V1 (Eclipse)</a></li> <li><a href="/wiki/Comet_Arend%E2%80%93Roland" title="Comet Arend–Roland">C/1956 R1 (Arend–Roland)</a></li> <li><a href="/wiki/C/1957_P1_(Mrkos)" title="C/1957 P1 (Mrkos)">C/1957 P1 (Mrkos)</a></li> <li><a href="/w/index.php?title=C/1961_O1_(Wilson-Hubbard)&action=edit&redlink=1" class="new" title="C/1961 O1 (Wilson-Hubbard) (page does not exist)">C/1961 O1 (Wilson-Hubbard)</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/C/1961_O1_(Wilson-Hubbard)" class="extiw" title="de:C/1961 O1 (Wilson-Hubbard)">de</a>]</span></li> <li><a href="/wiki/Comet_Humason" title="Comet Humason">C/1961 R1 (Humason)</a></li> <li><a href="/wiki/C/1962_C1_(Seki-Lines)" class="mw-redirect" title="C/1962 C1 (Seki-Lines)">C/1962 C1 (Seki-Lines)</a></li> <li><a href="/wiki/C/1963_A1_(Ikeya)" title="C/1963 A1 (Ikeya)">C/1963 A1 (Ikeya)</a></li> <li><a href="/wiki/Comet_Pereyra" title="Comet Pereyra">C/1963 R1 (Pereyra)</a></li> <li><a href="/wiki/C/1964_N1_(Ikeya)" title="C/1964 N1 (Ikeya)">C/1964 N1 (Ikeya)</a></li> <li><a href="/wiki/Comet_Ikeya%E2%80%93Seki" title="Comet Ikeya–Seki">C/1965 S1 (Ikeya-Seki)</a></li> <li><a href="/w/index.php?title=C/1969_T1_(Tago-Sato-Kosaka)&action=edit&redlink=1" class="new" title="C/1969 T1 (Tago-Sato-Kosaka) (page does not exist)">C/1969 T1 (Tago-Sato-Kosaka)</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/C/1969_T1_(Tago-Sato-Kosaka)" class="extiw" title="de:C/1969 T1 (Tago-Sato-Kosaka)">de</a>]</span></li> <li><a href="/wiki/Comet_Bennett" title="Comet Bennett">C/1969 Y1 (Bennett)</a></li> <li><a href="/wiki/Comet_White%E2%80%93Ortiz%E2%80%93Bolelli" title="Comet White–Ortiz–Bolelli">C/1970 K1 (White–Ortiz–Bolelli)</a></li> <li><a href="/wiki/Comet_Kohoutek" title="Comet Kohoutek">C/1973 E1 (Kohoutek)</a></li> <li><a href="/wiki/Comet_West" title="Comet West">C/1975 V1 (West)</a></li> <li><a href="/wiki/C/1980_E1_(Bowell)" title="C/1980 E1 (Bowell)">C/1980 E1 (Bowell)</a></li> <li><a href="/wiki/Comet_IRAS%E2%80%93Araki%E2%80%93Alcock" title="Comet IRAS–Araki–Alcock">C/1983 H1 (IRAS–Araki–Alcock)</a></li> <li><a href="/wiki/C/1989_W1_(Aarseth-Brewington)" class="mw-redirect" title="C/1989 W1 (Aarseth-Brewington)">C/1989 W1 (Aarseth-Brewington)</a></li> <li><a href="/wiki/C/1989_X1_(Austin)" title="C/1989 X1 (Austin)">C/1989 X1 (Austin)</a></li> <li><a href="/wiki/Comet_Skorichenko%E2%80%93George" class="mw-redirect" title="Comet Skorichenko–George">C/1989 Y1 (Skorichenko–George)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">After 1990</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/C/1990_K1_(Levy)" title="C/1990 K1 (Levy)">C/1990 K1 (Levy)</a></li> <li><a href="/wiki/C/1992_J1_(Spacewatch)" title="C/1992 J1 (Spacewatch)">C/1992 J1 (Spacewatch–Rabinowitz)</a></li> <li><a href="/wiki/Comet_McNaught%E2%80%93Russell" class="mw-redirect" title="Comet McNaught–Russell">C/1993 Y1 (McNaught–Russell)</a></li> <li><a href="/wiki/Comet_Hale%E2%80%93Bopp" title="Comet Hale–Bopp">C/1995 O1 (Hale–Bopp)</a></li> <li><a href="/wiki/Comet_Hyakutake" title="Comet Hyakutake">C/1996 B2 (Hyakutake)</a></li> <li><a href="/wiki/Comet_Zhu%E2%80%93Balam" class="mw-redirect" title="Comet Zhu–Balam">C/1997 L1 (Zhu–Balam)</a></li> <li><a href="/wiki/Comet_Stonehouse" class="mw-redirect" title="Comet Stonehouse">C/1998 H1 (Stonehouse)</a></li> <li><a href="/w/index.php?title=C/1998_J1_(SOHO)&action=edit&redlink=1" class="new" title="C/1998 J1 (SOHO) (page does not exist)">C/1998 J1 (SOHO)</a></li> <li><a href="/wiki/C/1999_F1_(Catalina)" title="C/1999 F1 (Catalina)">C/1999 F1 (Catalina)</a></li> <li><a href="/wiki/C/1999_S4_(LINEAR)" title="C/1999 S4 (LINEAR)">C/1999 S4 (LINEAR)</a></li> <li><a href="/wiki/C/2000_WM1_(LINEAR)" title="C/2000 WM1 (LINEAR)">C/2000 WM1 (LINEAR)</a></li> <li><a href="/wiki/C/2001_A2_(LINEAR)" title="C/2001 A2 (LINEAR)">C/2001 A2 (LINEAR)</a></li> <li><a href="/wiki/C/2001_OG108" class="mw-redirect" title="C/2001 OG108">C/2001 OG108 (LONEOS)</a></li> <li><a href="/wiki/C/2001_Q4_(NEAT)" title="C/2001 Q4 (NEAT)">C/2001 Q4 (NEAT)</a></li> <li><a href="/wiki/C/2002_T7" class="mw-redirect" title="C/2002 T7">C/2002 T7 (LINEAR)</a></li> <li><a href="/wiki/C/2002_V1_(NEAT)" title="C/2002 V1 (NEAT)">C/2002 V1 (NEAT)</a></li> <li><a href="/wiki/C/2004_F4_(Bradfield)" title="C/2004 F4 (Bradfield)">C/2004 F4 (Bradfield)</a></li> <li><a href="/wiki/Comet_Machholz" title="Comet Machholz">C/2004 Q2 (Machholz)</a></li> <li><a href="/wiki/Comet_Pojma%C5%84ski" class="mw-redirect" title="Comet Pojmański">C/2006 A1 (Pojmański)</a></li> <li><a href="/wiki/C/2006_M4_(SWAN)" title="C/2006 M4 (SWAN)">C/2006 M4 (SWAN)</a></li> <li><a href="/wiki/Comet_McNaught" title="Comet McNaught">C/2006 P1 (McNaught)</a></li> <li><a href="/wiki/C/2007_E2_(Lovejoy)" title="C/2007 E2 (Lovejoy)">C/2007 E2 (Lovejoy)</a></li> <li><a href="/wiki/C/2007_F1" class="mw-redirect" title="C/2007 F1">C/2007 F1 (LONEOS)</a></li> <li><a href="/wiki/Comet_Lulin" class="mw-redirect" title="Comet Lulin">C/2007 N3 (Lulin)</a></li> <li><a href="/wiki/C/2007_Q3_(Siding_Spring)" title="C/2007 Q3 (Siding Spring)">C/2007 Q3 (Siding Spring)</a></li> <li><a href="/wiki/C/2007_W1_(Boattini)" title="C/2007 W1 (Boattini)">C/2007 W1 (Boattini)</a></li> <li><a href="/wiki/Comet_Yi%E2%80%93SWAN" class="mw-redirect" title="Comet Yi–SWAN">C/2009 F6 (Yi–SWAN)</a></li> <li><a href="/wiki/C/2009_R1_(McNaught)" title="C/2009 R1 (McNaught)">C/2009 R1 (McNaught)</a></li> <li><a href="/wiki/C/2010_X1_(Elenin)" title="C/2010 X1 (Elenin)">C/2010 X1 (Elenin)</a></li> <li><a href="/wiki/C/2011_L4" class="mw-redirect" title="C/2011 L4">C/2011 L4 (PANSTARRS)</a></li> <li><a href="/wiki/C/2011_W3_(Lovejoy)" title="C/2011 W3 (Lovejoy)">C/2011 W3 (Lovejoy)</a></li> <li><a href="/wiki/C/2012_E2_(SWAN)" title="C/2012 E2 (SWAN)">C/2012 E2 (SWAN)</a></li> <li><a href="/wiki/C/2012_F6_(Lemmon)" title="C/2012 F6 (Lemmon)">C/2012 F6 (Lemmon)</a></li> <li><a href="/wiki/C/2012_K1" class="mw-redirect" title="C/2012 K1">C/2012 K1 (PANSTARRS)</a></li> <li><a href="/wiki/Comet_ISON" title="Comet ISON">C/2012 S1 (ISON)</a></li> <li><a href="/wiki/C/2013_A1_(Siding_Spring)" title="C/2013 A1 (Siding Spring)">C/2013 A1 (Siding Spring)</a></li> <li><a href="/wiki/C/2013_R1" class="mw-redirect" title="C/2013 R1">C/2013 R1 (Lovejoy)</a></li> <li><a href="/wiki/C/2013_US10_(Catalina)" title="C/2013 US10 (Catalina)">C/2013 US10 (Catalina)</a></li> <li><a href="/wiki/C/2013_V5_(Oukaimeden)" title="C/2013 V5 (Oukaimeden)">C/2013 V5 (Oukaimeden)</a></li> <li><a href="/wiki/C/2014_E2_(Jacques)" title="C/2014 E2 (Jacques)">C/2014 E2 (Jacques)</a></li> <li><a href="/wiki/C/2014_Q1_(PanSTARRS)" title="C/2014 Q1 (PanSTARRS)">C/2014 Q1 (PanSTARRS)</a></li> <li><a href="/wiki/C/2014_Q2_(Lovejoy)" title="C/2014 Q2 (Lovejoy)">C/2014 Q2 (Lovejoy)</a></li> <li><a href="/wiki/C/2015_ER61_(PanSTARRS)" title="C/2015 ER61 (PanSTARRS)">C/2015 ER61 (PanSTARRS)</a></li> <li><a href="/wiki/C/2015_V2_(Johnson)" title="C/2015 V2 (Johnson)">C/2015 V2 (Johnson)</a></li> <li><a href="/wiki/C/2017_K2_(PanSTARRS)" title="C/2017 K2 (PanSTARRS)">C/2017 K2 (PanSTARRS)</a></li> <li><a href="/wiki/%CA%BBOumuamua" title="ʻOumuamua">1I/2017 U1 ʻOumuamua</a></li> <li><a href="/wiki/C/2018_Y1_(Iwamoto)" title="C/2018 Y1 (Iwamoto)">C/2018 Y1 (Iwamoto)</a></li> <li><a class="mw-selflink selflink">2I/Borisov</a></li> <li><a href="/wiki/C/2019_U6_(Lemmon)" title="C/2019 U6 (Lemmon)">C/2019 U6 (Lemmon)</a></li> <li><a href="/wiki/C/2019_Y4_(ATLAS)" title="C/2019 Y4 (ATLAS)">C/2019 Y4 (ATLAS)</a></li> <li><a href="/wiki/C/2020_F3_(NEOWISE)" class="mw-redirect" title="C/2020 F3 (NEOWISE)">C/2020 F3 (NEOWISE)</a></li> <li><a href="/wiki/C/2020_F8_(SWAN)" title="C/2020 F8 (SWAN)">C/2020 F8 (SWAN)</a></li> <li><a href="/wiki/C/2021_A1_(Leonard)" title="C/2021 A1 (Leonard)">C/2021 A1 (Leonard)</a></li> <li><a href="/wiki/C/2022_E3_(ZTF)" title="C/2022 E3 (ZTF)">C/2022 E3 (ZTF)</a></li> <li><a href="/wiki/C/2023_A3_(Tsuchinshan%E2%80%93ATLAS)" title="C/2023 A3 (Tsuchinshan–ATLAS)">C/2023 A3 (Tsuchinshan–ATLAS)</a></li> <li><a href="/wiki/C/2023_P1_(Nishimura)" title="C/2023 P1 (Nishimura)">C/2023 P1 (Nishimura)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align: center;">After 1910<br />(by name)</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/C/1989_W1_(Aarseth-Brewington)" class="mw-redirect" title="C/1989 W1 (Aarseth-Brewington)">Aarseth-Brewington</a></li> <li><a href="/wiki/Comet_Arend%E2%80%93Roland" title="Comet Arend–Roland">Arend–Roland</a></li> <li><a href="/wiki/C/1989_X1_(Austin)" title="C/1989 X1 (Austin)">Austin</a></li> <li><a href="/wiki/C/1911_S3" class="mw-redirect" title="C/1911 S3">Beljawsky</a></li> <li><a href="/wiki/Comet_Bennett" title="Comet Bennett">Bennett</a></li> <li><a href="/wiki/C/2007_W1_(Boattini)" title="C/2007 W1 (Boattini)">Boattini</a></li> <li><a class="mw-selflink selflink">Borisov</a></li> <li><a href="/wiki/C/1980_E1_(Bowell)" title="C/1980 E1 (Bowell)">Bowell</a></li> <li><a href="/wiki/C/2004_F4_(Bradfield)" title="C/2004 F4 (Bradfield)">Bradfield</a></li> <li><a href="/wiki/C/1911_O1" class="mw-redirect" title="C/1911 O1">Brooks</a></li> <li><a href="/wiki/Catalina_Sky_Survey" title="Catalina Sky Survey">Catalina</a> <ul><li><a href="/wiki/C/1999_F1_(Catalina)" title="C/1999 F1 (Catalina)">C/1999 F1</a></li> <li><a href="/wiki/C/2013_US10" class="mw-redirect" title="C/2013 US10">C/2013 US10</a></li></ul></li> <li><a href="/wiki/C/1941_B2_(de_Kock-Paraskevopoulos)" class="mw-redirect" title="C/1941 B2 (de Kock-Paraskevopoulos)">de Kock–Paraskevopoulos</a></li> <li><a href="/wiki/C/1948_V1" title="C/1948 V1">Eclipse</a></li> <li><a href="/wiki/C/2010_X1_(Elenin)" title="C/2010 X1 (Elenin)">Elenin</a></li> <li><a href="/wiki/Comet_Hale%E2%80%93Bopp" title="Comet Hale–Bopp">Hale-Bopp</a></li> <li><a href="/wiki/Comet_Humason" title="Comet Humason">Humason</a></li> <li><a href="/wiki/Comet_Hyakutake" title="Comet Hyakutake">Hyakutake</a></li> <li><a href="/wiki/Kaoru_Ikeya" title="Kaoru Ikeya">Ikeya</a> <ul><li><a href="/wiki/C/1963_A1_(Ikeya)" title="C/1963 A1 (Ikeya)">C/1963 A1</a></li> <li><a href="/wiki/C/1964_N1_(Ikeya)" title="C/1964 N1 (Ikeya)">C/1964 N1</a></li></ul></li> <li><a href="/wiki/Comet_Ikeya%E2%80%93Seki" title="Comet Ikeya–Seki">Ikeya-Seki</a></li> <li><a href="/wiki/Comet_IRAS%E2%80%93Araki%E2%80%93Alcock" title="Comet IRAS–Araki–Alcock">IRAS–Araki–Alcock</a></li> <li><a href="/wiki/Comet_ISON" title="Comet ISON">ISON</a></li> <li><a href="/wiki/C/2018_Y1_(Iwamoto)" title="C/2018 Y1 (Iwamoto)">Iwamoto</a></li> <li><a href="/wiki/C/2014_E2_(Jacques)" title="C/2014 E2 (Jacques)">Jacques</a></li> <li><a href="/wiki/C/2015_V2_(Johnson)" title="C/2015 V2 (Johnson)">Johnson</a></li> <li><a href="/wiki/Comet_Kohoutek" title="Comet Kohoutek">Kohoutek</a></li> <li><a href="/wiki/Mount_Lemmon_Observatory" title="Mount Lemmon Observatory">Lemmon</a> <ul><li><a href="/wiki/C/2012_F6_(Lemmon)" title="C/2012 F6 (Lemmon)">C/2012 F6</a></li> <li><a href="/wiki/C/2018_C2_(Lemmon)" title="C/2018 C2 (Lemmon)">C/2018 C2</a></li> <li><a href="/wiki/C/2019_U6_(Lemmon)" title="C/2019 U6 (Lemmon)">C/2019 U6</a></li></ul></li> <li><a href="/wiki/C/2021_A1_(Leonard)" title="C/2021 A1 (Leonard)">Leonard</a></li> <li><a href="/wiki/C/1990_K1_(Levy)" title="C/1990 K1 (Levy)">Levy</a></li> <li><a href="/wiki/Lincoln_Near-Earth_Asteroid_Research" title="Lincoln Near-Earth Asteroid Research">LINEAR</a> <ul><li><a href="/wiki/C/1999_S4_(LINEAR)" title="C/1999 S4 (LINEAR)">C/1999 S4</a></li> <li><a href="/wiki/C/2000_WM1_(LINEAR)" title="C/2000 WM1 (LINEAR)">C/2000 WM1</a></li> <li><a href="/wiki/C/2001_A2_(LINEAR)" title="C/2001 A2 (LINEAR)">C/2001 A2</a></li> <li><a href="/wiki/C/2002_T7" class="mw-redirect" title="C/2002 T7">C/2002 T7</a></li></ul></li> <li><a href="/wiki/Lowell_Observatory_Near-Earth-Object_Search" title="Lowell Observatory Near-Earth-Object Search">LONEOS</a> <ul><li><a href="/wiki/C/2001_OG108" class="mw-redirect" title="C/2001 OG108">C/2001 OG108</a></li> <li><a href="/wiki/C/2007_F1" class="mw-redirect" title="C/2007 F1">C/2007 F1</a></li></ul></li> <li><a href="/wiki/Terry_Lovejoy" title="Terry Lovejoy">Lovejoy</a> <ul><li><a href="/wiki/C/2007_E2_(Lovejoy)" title="C/2007 E2 (Lovejoy)">C/2007 E2</a></li> <li><a href="/wiki/C/2011_W3_(Lovejoy)" title="C/2011 W3 (Lovejoy)">C/2011 W3</a></li> <li><a href="/wiki/C/2013_R1" class="mw-redirect" title="C/2013 R1">C/2013 R1</a></li> <li><a href="/wiki/C/2014_Q2_(Lovejoy)" title="C/2014 Q2 (Lovejoy)">C/2014 Q2</a></li></ul></li> <li><a href="/wiki/Comet_Lulin" class="mw-redirect" title="Comet Lulin">Lulin</a></li> <li><a href="/wiki/Comet_Machholz" title="Comet Machholz">Machholz</a></li> <li><a href="/wiki/Robert_H._McNaught" title="Robert H. McNaught">McNaught</a> <ul><li><a href="/wiki/Comet_McNaught" title="Comet McNaught">C/2006 P1</a></li> <li><a href="/wiki/C/2009_R1_(McNaught)" title="C/2009 R1 (McNaught)">C/2009 R1</a></li></ul></li> <li><a href="/wiki/Comet_McNaught%E2%80%93Russell" class="mw-redirect" title="Comet McNaught–Russell">McNaught–Russell</a></li> <li><a href="/wiki/C/1957_P1_(Mrkos)" title="C/1957 P1 (Mrkos)">Mrkos</a></li> <li><a href="/wiki/Near-Earth_Asteroid_Tracking" title="Near-Earth Asteroid Tracking">NEAT</a> <ul><li><a href="/wiki/C/2001_Q4_(NEAT)" title="C/2001 Q4 (NEAT)">C/2001 Q4</a></li> <li><a href="/wiki/C/2002_V1_(NEAT)" title="C/2002 V1 (NEAT)">C/2002 V1</a></li></ul></li> <li><a href="/wiki/Comet_NEOWISE" title="Comet NEOWISE">NEOWISE</a></li> <li><a href="/wiki/C/2023_P1_(Nishimura)" title="C/2023 P1 (Nishimura)">Nishimura</a></li> <li><a href="/wiki/C/2013_V5_(Oukaimeden)" title="C/2013 V5 (Oukaimeden)">Oukaimeden</a></li> <li><a href="/wiki/%CA%BBOumuamua" title="ʻOumuamua">ʻOumuamua</a></li> <li><a href="/wiki/Pan-STARRS" title="Pan-STARRS">Pan-STARRS</a> <ul><li><a href="/wiki/C/2011_L4" class="mw-redirect" title="C/2011 L4">C/2011 L4</a></li> <li><a href="/wiki/C/2012_K1" class="mw-redirect" title="C/2012 K1">C/2012 K1</a></li> <li><a href="/wiki/311P/PanSTARRS" title="311P/PanSTARRS">311P/PanSTARRS</a></li> <li><a href="/wiki/C/2014_Q1_(PanSTARRS)" title="C/2014 Q1 (PanSTARRS)">C/2014 Q1</a></li> <li><a href="/wiki/C/2015_ER61_(PanSTARRS)" title="C/2015 ER61 (PanSTARRS)">C/2015 ER61</a></li> <li><a href="/wiki/C/2017_K2" class="mw-redirect" title="C/2017 K2">C/2017 K2</a></li></ul></li> <li><a href="/wiki/Comet_Pereyra" title="Comet Pereyra">Pereyra</a></li> <li><a href="/wiki/Comet_Pojma%C5%84ski" class="mw-redirect" title="Comet Pojmański">Pojmański</a></li> <li><a href="/wiki/Ryves_Comet" title="Ryves Comet">Ryves</a></li> <li><a href="/wiki/C/1962_C1_(Seki-Lines)" class="mw-redirect" title="C/1962 C1 (Seki-Lines)">Seki–Lines</a></li> <li><a href="/wiki/Siding_Spring_Observatory" title="Siding Spring Observatory">Siding Spring</a> <ul><li><a href="/wiki/C/2007_Q3_(Siding_Spring)" title="C/2007 Q3 (Siding Spring)">C/2007 Q3</a></li> <li><a href="/wiki/C/2013_A1_(Siding_Spring)" title="C/2013 A1 (Siding Spring)">C/2013 A1</a></li></ul></li> <li><a href="/wiki/Comet_Skjellerup%E2%80%93Maristany" title="Comet Skjellerup–Maristany">Skjellerup–Maristany</a></li> <li><a href="/wiki/Comet_Skorichenko%E2%80%93George" class="mw-redirect" title="Comet Skorichenko–George">Skorichenko–George</a></li> <li><a href="/w/index.php?title=C/1998_J1_(SOHO)&action=edit&redlink=1" class="new" title="C/1998 J1 (SOHO) (page does not exist)">SOHO</a></li> <li><a href="/wiki/C/1947_X1_(Southern_Comet)" class="mw-redirect" title="C/1947 X1 (Southern Comet)">Southern</a></li> <li><a href="/wiki/C/1992_J1_(Spacewatch)" title="C/1992 J1 (Spacewatch)">Spacewatch–Rabinowitz</a></li> <li><a href="/wiki/Comet_Stonehouse" class="mw-redirect" title="Comet Stonehouse">Stonehouse</a></li> <li><a href="/wiki/Solar_and_Heliospheric_Observatory#Instruments" title="Solar and Heliospheric Observatory">SWAN</a> <ul><li><a href="/wiki/C/2006_M4_(SWAN)" title="C/2006 M4 (SWAN)">C/2006 M4</a></li> <li><a href="/wiki/C/2012_E2_(SWAN)" title="C/2012 E2 (SWAN)">C/2012 E2</a></li> <li><a href="/wiki/C/2020_F8_(SWAN)" title="C/2020 F8 (SWAN)">C/2020 F8</a></li></ul></li> <li><a href="/w/index.php?title=C/1969_T1_(Tago-Sato-Kosaka)&action=edit&redlink=1" class="new" title="C/1969 T1 (Tago-Sato-Kosaka) (page does not exist)">Tago-Sato-Kosaka</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/C/1969_T1_(Tago-Sato-Kosaka)" class="extiw" title="de:C/1969 T1 (Tago-Sato-Kosaka)">de</a>]</span></li> <li><a href="/wiki/C/2023_A3_(Tsuchinshan%E2%80%93ATLAS)" title="C/2023 A3 (Tsuchinshan–ATLAS)">Tsuchinshan–ATLAS</a></li> <li><a href="/wiki/Comet_West" title="Comet West">West</a></li> <li><a href="/wiki/Comet_White%E2%80%93Ortiz%E2%80%93Bolelli" title="Comet White–Ortiz–Bolelli">White–Ortiz–Bolelli</a></li> <li><a href="/w/index.php?title=C/1961_O1_(Wilson-Hubbard)&action=edit&redlink=1" class="new" title="C/1961 O1 (Wilson-Hubbard) (page does not exist)">Wilson–Hubbard</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://de.wikipedia.org/wiki/C/1961_O1_(Wilson-Hubbard)" class="extiw" title="de:C/1961 O1 (Wilson-Hubbard)">de</a>]</span></li> <li><a href="/wiki/Comet_Yi%E2%80%93SWAN" class="mw-redirect" title="Comet Yi–SWAN">Yi–SWAN</a></li> <li><a href="/wiki/Comet_Zhu%E2%80%93Balam" class="mw-redirect" title="Comet Zhu–Balam">Zhu–Balam</a></li> <li><a href="/wiki/C/2022_E3_(ZTF)" title="C/2022 E3 (ZTF)">ZTF</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr></tbody></table><div></div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="text-align: center;"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Comets" title="Category:Comets">Category</a></li></ul> </div></td></tr></tbody></table></div> <style data-mw-deduplicate="TemplateStyles:r1130092004">.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;justify-content:center;align-items:baseline}.mw-parser-output .portal-bar-bordered{padding:0 2em;background-color:#fdfdfd;border:1px solid #a2a9b1;clear:both;margin:1em auto 0}.mw-parser-output .portal-bar-related{font-size:100%;justify-content:flex-start}.mw-parser-output .portal-bar-unbordered{padding:0 1.7em;margin-left:0}.mw-parser-output .portal-bar-header{margin:0 1em 0 0.5em;flex:0 0 auto;min-height:24px}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;flex:0 1 auto;padding:0.15em 0;column-gap:1em;align-items:baseline;margin:0;list-style:none}.mw-parser-output .portal-bar-content-related{margin:0;list-style:none}.mw-parser-output .portal-bar-item{display:inline-block;margin:0.15em 0.2em;min-height:24px;line-height:24px}@media screen and (max-width:768px){.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;flex-flow:column wrap;align-items:baseline}.mw-parser-output .portal-bar-header{text-align:center;flex:0;padding-left:0.5em;margin:0 auto}.mw-parser-output .portal-bar-related{font-size:100%;align-items:flex-start}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;align-items:center;flex:0;column-gap:1em;border-top:1px solid #a2a9b1;margin:0 auto;list-style:none}.mw-parser-output .portal-bar-content-related{border-top:none;margin:0;list-style:none}}.mw-parser-output .navbox+link+.portal-bar,.mw-parser-output .navbox+style+.portal-bar,.mw-parser-output .navbox+link+.portal-bar-bordered,.mw-parser-output .navbox+style+.portal-bar-bordered,.mw-parser-output .sister-bar+link+.portal-bar,.mw-parser-output .sister-bar+style+.portal-bar,.mw-parser-output .portal-bar+.navbox-styles+.navbox,.mw-parser-output .portal-bar+.navbox-styles+.sister-bar{margin-top:-1px}</style><div class="portal-bar noprint metadata noviewer portal-bar-bordered" role="navigation" aria-label="Portals"><span class="portal-bar-header"><a href="/wiki/Wikipedia:Contents/Portals" title="Wikipedia:Contents/Portals">Portals</a>:</span><ul 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