Near-Earth Objects

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class="fixed-content-margin"></div> </div>  <div id="main_content" tabindex="-1" class="container-fluid hide-tabindex">   <noscript> <div class="alert alert-danger"> <h4>Please enable JavaScript for this website.</h4> <p> This website makes extensive use of JavaScript. The top menus will not function without it and most tools will also not work. </p> <p> If you do not know how to enable JavaScript in your web browser, you should be able find instructions by searching the web for "enable javascript in my browser" (or similar). </p> </div> </noscript> <h1 class="no-top-margin">Near-Earth Objects</h1> <blockquote> <p>Visit <a href="https://cneos.jpl.nasa.gov">CNEOS</a> (the Center for Near-Earth Object Studies) website for more information related to NEOs.</p> </blockquote> <p>NEOs are a broad category of small-bodies defined as those with a trajectory that can come within 1.3 au of the Sun. Since the Earth orbits at approximately 1聽au, such objects can in principle come within 0.3聽au of Earth. However, being in the NEO category doesn鈥檛 mean they are actually close to Earth at any particular time, only that their motion can, at times, bring them close to the Sun and possibly Earth.</p> <p>NEOS are of interest because they have trajectories that make them relatively easy to get to with spacecraft, or observe and characterize with <a href="/sb/radar.html">ground-based radar</a>. Their low surface gravity can simplify spacecraft operations while providing a representative sample of solar system materials and history, since most have evolved into the inner solar system from elsewhere after millions of years of gravitationally interacting with the planets.</p> <p>A subset of NEOs can potentially impact the Earth, so their trajectories are of particular interest and the focused subject of our related CNEOS website.</p>  <div id="footer" class="container-fluid footer"> <div class="row"> <div class="col-sm-5 col-xs-12"> <img class="ssd-logo" src="/images/ssd_logo.png" alt="SSD Logo" /> </div> <div class="col-sm-3 col-xs-12"> <div class="link-inv"> <a href="/sitemap.html"><i class="fa-fw fa fa-list-alt"></i> Site Map</a> </div> <div class="link-inv"> <a href="https://www.jpl.nasa.gov/caltechjpl-privacy-policies-and-important-notices"><i class="fa-fw fa fa-user-secret"></i> Privacy</a> </div> <div class="link-inv"> <a href="https://www.jpl.nasa.gov/jpl-image-use-policy"><i class="fa-fw fa fa-picture-o"></i> Image Policy</a> </div> </div> <div class="col-sm-4 col-xs-12"> <div class=" link-inv"> <a href="/contact/"><i class="fa-fw fa fa-envelope"></i> Contact Us</a> </div> <div class="text-smaller"> <span class="footer-label text-nowrap">Site Manager:</span> <span class="text-nowrap">Ryan Park</span> </div> <div class="text-smaller2"> <span class="footer-label text-nowrap">Site Design:</span> <span class="text-nowrap">Alan B. 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Near-Earth Objects