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<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("http://alienworlds.southwales.ac.uk:80/milkyWay.html","20130612041907","https://web.archive.org/","web","/_static/", "1371010747"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <title>Milky Way | Alien Worlds: Shedding light on our unearthly universe</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/> <meta name="keywords" content="Milky Way, solar system, galaxy, spiral galaxy"/> <meta name="description" content="A guide to the Milky Way."/> <link href="/web/20130612041907cs_/http://alienworlds.southwales.ac.uk/alienWorlds.css" rel="stylesheet" type="text/css"/>  <script type="text/javascript" src="/web/20130612041907js_/http://alienworlds.southwales.ac.uk/swfobject/swfobject.js"></script> <script type="text/javascript" src="/web/20130612041907js_/http://alienworlds.southwales.ac.uk/swfaddress/swfaddress.js"></script> </head> <body> <div id="container"> <div id="header"> <a href="index.html"><img alt="Alien Worlds: Shedding light on our unearthly universe." src="/web/20130612041907im_/http://alienworlds.southwales.ac.uk/images/alienWorldsBanner.jpg"/></a> </div> <div id="navigation"> <ul id="nav"> <li id="retrograde"><a href="retrogradeOrbits.html">Retrograde Orbits</a></li> <li id="sun"><a href="sunStructure.html">The structure of the Sun</a></li> <li id="jovian"><a href="jovianMoons.html">Jovian Moons</a></li> <li id="solar"><a href="solarEclipse.html">Solar Eclipse</a></li> <li id="lunar"><a href="lunarEclipse.html">Lunar Eclipse</a></li> <li id="milky"><a href="#">Milky Way</a></li> <li id="orion"><a href="orionNebula.html">Orion Nebula</a></li> </ul> </div> <div id="heading"> <h1 id="milkyTitle">Milky Way</h1> </div> <div class="content"> <p>We've found that there are more stars in the <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Universe" target="_blank">Universe</a> than there are grains of sand on all of the beaches on planet Earth. It's worth pausing to imagine being on one of those beaches with its soft golden sand sweeping off into the distance. Bright sunny day, of course. In fact, let's make it the Caribbean. No expense spared. You reach down, hands cupped, and gather up two handfuls of that golden sand. Then you let the sand fall through your fingers, the grains glistening as they catch the sunlight. Each grain is a star. And each star is a sun, like our own local star, the Sun. You saunter on a few more steps, and again you gather up the sand and let it fall. And so on, over all the beaches on Earth. So much sand, so many stars.</p> <p><a href="#contentContinues">Story continues below animation.</a></p> </div> <div id="flashContent"> <p class="noFlash">You require the latest version of the Flash player plugin to view some of the content on this site.<br/> The Flash player is free and quick to download, please follow the link below to get the correct version. Once you have installed Flash, return to our site and you will be able to view all the content on our site. <br/><a href="https://web.archive.org/web/20130612041907/http://www.adobe.com/go/getflashplayer"><img src="https://web.archive.org/web/20130612041907im_/http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash Player"/></a></p> </div> <script type="text/javascript"> // <![CDATA[ var so = new SWFObject('MilkyWay.swf', 'MilkyWay', '990', '480', '9', '#000000'); so.useExpressInstall('swfobject/expressinstall.swf'); so.addParam('menu', 'false'); so.write('flashContent'); // ]]> </script> <div class="content" id="contentContinues"> <p id="itunesUlink"><a id="openiTunes" href="https://web.archive.org/web/20130612041907/https://itunes.apple.com/gb/itunes-u/alien-worlds/id527125588?mt=10"><span>Download this animation from iTunes U</span></a></p> <p>On a large scale, swarms of such stars dwell in <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Galaxy" target="_blank">galaxies</a>, effortlessly wheeling their way through the vastness of deep space. Each galaxy contains millions, if not billions, of stars. Under cover of the night sky, some galaxies can be seen with the naked eye. It's worth remembering that the very word ‘galaxy’ derives from the Greek term <em>galaxias</em>, or ‘milky circle’, for its appearance to the eye.</p> <p>Imagine yourself again, on our same trip, under the starry reach of the Caribbean sky. You look up, the star field is dazzling. But here and there is the odd, nebulous smudge of a galaxy. The great galaxy in the constellation <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Andromeda_Galaxy" target="_blank">Andromeda</a>, for instance: one of our near neighbours, and yet even this nearby citadel of stars is resolvable only by <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Telescope" target="_blank">telescope</a>.</p> <p>So that's how galaxies look to the naked eye: like tiny, pale thumbprints in the sky. And yet the <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Milky_Way" target="_blank">Milky Way Galaxy</a> alone holds between 200 and 400 billion stars, and has special significance since it is the home galaxy of planet Earth. The capitalised word ‘Galaxy’ refers particularly to our own Milky Way, to distinguish it from the hundred-billion or so other galaxies in the <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Observable_universe" target="_blank">observable Universe</a>.</p> <p>Galaxies such as our Milky Way are known as <a href="https://web.archive.org/web/20130612041907/http://en.wikipedia.org/wiki/Spiral_galaxy" target="_blank">spiral galaxies</a> because they have a core at the centre, surrounded by a disk of gas, dust and stars forming spiral arms. Many astronomers believe it is in spiral arms that star formation continues today. And where there are new stars, they may be new planets, and new life…</p> </div> <div id="footer"> <p><a href="copyright.html">© 2008-2013 University of South Wales</a> | Supported by <a href="https://web.archive.org/web/20130612041907/http://ec.europa.eu/employment_social/esf/index_en.htm" target="_blank">The European Social Fund</a> | <a href="credits.html">Credits</a> | <a href="links.html">Links</a></p> </div> </div> <script type="text/javascript"> var gaJsHost = (("https:" == document.location.protocol) ? "https://web.archive.org/web/20130612041907/https://ssl." : "https://web.archive.org/web/20130612041907/http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); </script> <script type="text/javascript"> try { var pageTracker = _gat._getTracker("UA-4874760-1"); pageTracker._trackPageview(); } catch(err) {}</script> </body> </html>