https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=Darrenleomiller 2026-04-16T21:47:35Z User contributions MediaWiki 1.30.0 https://www.explainxkcd.com/wiki/index.php?title=1297:_Oort_Cloud&diff=53948 2013-11-29T14:39:04Z

<p>Darrenleomiller: Capitalizing &quot;Earth&quot;</p> <hr /> <div>{{comic<br /> | number = 1297<br /> | date = November 29, 2013<br /> | title = Oort Cloud<br /> | image = oort_cloud.png<br /> | titletext = ... I wanna try. Hang on, be right back.<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|Not (yet) complete.}}<br /> The {{w|Oort cloud}} is a cloud mostly composed of comets that makes up the outer region of our solar system, reaching out to roughly 50,000 {{w|AU}} or nearly one light-year from the sun. Gravitational forces from passing stars and the Milky Way sometimes perturb a comet enough to send it into the inner solar system. When the comet gets closer to the Sun (which is the “bright dot in the distance” here) it warms up and some of its body is lost as gas and dust, sometimes visible as a coma and perhaps a tail. If it gets close to the sun it may break up entirely.<br /> <br /> The comet pictured here upon its return resembles the unusual asteroid/comet {{w|P/2013 P5}} which sported six comet-like tails. In that case they seem to have been generated partly by rapid spinning.<br /> <br /> {{w|Comet ISON}} came from the Oort cloud and reached its closest approach to the sun ({{w|perihelion}}) on the day before this comic was published. The comet passed very close to the sun, at a distance of 1,860,000 kilometers or 1,150,000 miles. It was thus within one sun-diameter of the surface of the sun itself. The tail has changed its shape because the comet was partly broken up around the sun. The closest approach to Earth will be on December 27, 2013 but it's not clear if the comet will be visible by the naked eye.<br /> <br /> This video shows an animation of the encounter at the sun: [http://stereo-ssc.nascom.nasa.gov/browse/2013/11/28/ahead_20131128_cor2_rdiff_512.mpg ISON 28.11.2013].<br /> <br /> ==Transcript==<br /> :[Three asteroids float in space.]<br /> :ISON: Have you noticed that bright dot in the distance?<br /> :Asteroid: Yeah. What's the deal with it?<br /> <br /> :ISON: Dunno. I'm gonna go check it out.<br /> <br /> :[Pause while ISON checks it out off screen.]<br /> <br /> :[Many thousand years later.]<br /> :ISON (appears burnt): Wow. Do NOT go over there.<br /> {{comic discussion}}<br /> [[Category:Astronomy]]</div>

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