1297: Oort Cloud

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Revision as of 19:54, 30 November 2013 by 108.162.222.227 (talk) (Oort Cloud not proven; it's just an idea.)
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Oort Cloud
... I wanna try. Hang on, be right back.
Title text: ... I wanna try. Hang on, be right back.

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: Not (yet) complete.
If you can address this issue, please edit the page! Thanks.

The Oort cloud is a hypothesised spherical collection of material far outside of our solar system. It's believed that many Asteroids exist at that distance reaching out to roughly 50,000 AU (astronomical units) or nearly one light-year from the sun. Gravitational forces from passing stars or collisions with other objects sometimes perturb an object enough to let them fall it into the inner solar system. When this object gets closer to the Sun (which is just a bright dot at that far distance) it warms up and some of its body is lost as gas and dust, visible as a comet and perhaps a tail. A new comet is born, and if it gets close enough to the sun it may break up entirely.

The comet pictured here upon its return maybe resembles the unusual asteroid P/2013 P5 which sported six comet-like tails, which wasn't a comet at all. In that case the six comet-like tails were suspected to be caused by rapid spinning of that object.

Comet ISON came from the Oort cloud and reached its closest approach to the sun (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 (diameter of sun = 1,391,000 km). At that distance the temperature at approx. 2,700 degrees Celsius does melt much more than only ice. That horror is just shown in last frame; even when it's not realistic that ISON still would have a tail at that far distance.

After this encounter 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.

This video shows an animation of the encounter at the sun: ISON 28.11.2013.

Transcript

[Three asteroids float in space.]
ISON: Have you noticed that bright dot in the distance?
Asteroid: Yeah. What's the deal with it?
ISON: Dunno. I'm gonna go check it out.
[Pause while ISON checks it out off screen.]
[Several million years later.]
ISON (appears burnt): Wow. Do NOT go over there.
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Discussion

Reading the Wikipedia page on the Oort Cloud didn't help me understand the joke. I don't know if it has anything to do with comets, or the asteroids getting smashed up by them. 108.162.238.117 05:15, 29 November 2013 (UTC)

The asteroid becomes a cost after being severely burnt by the sun. It warns the other asteroid not to go over there. 108.162.221.55 (talk) (please sign your comments with ~~~~)
Which, the title text indicates, is a warning that's utterly ignored... (Also being "right back" indicates a slower perceived thought process. As is probably the case for anything out there in such cold(-ish) depths of space.) 141.101.99.229 11:05, 29 November 2013 (UTC)
What does "becomes a cost" mean? is that a slang expression? 12:02, 29 November 2013 (UTC)
I think it's supposed to be "comet". 173.245.52.228 14:09, 29 November 2013 (UTC)
No, I think he means ghost. All thats left is a faint image after all. 141.101.99.214 (talk) (please sign your comments with ~~~~)

At least according to my freshman year science teacher, the Oort Cloud is just a theory, and hasn't been proven. Perhaps that should be made more clear? -- Wasda (talk) (please sign your comments with ~~~~)

@Wasda, A theory is something which is proven, if not its a hypothesis or a speculation. Mocking on "theories" is typical for laymen. 15:12, 30 November 2013 (UTC)~
Theory is the wrong term. Gravity is a theory. Evolution is a theory. The oort cloud is "hypothesized". Omega TalkContribs 06:21, 30 November 2013 (UTC)

What's here looks exactly in line with current comet theory: A comet is "perturbed" by interactions with other objects out there, and at that distance the sun is a very bright dot, no more. On return (chancy, based on both/either burning up or being in a no return hyperbolic orbit), what has come back is fragmented and with two tails. What I'm not seeing is the second level joke - it's in the movie "I'm going to check out x" form, but I don't get the specific quote. FractalgeekUK (talk) 13:55, 29 November 2013 (UTC)


According to http://www.nasa.gov/content/goddard/timeline-of-comet-ison-s-dangerous-journey, ISON's journey to earth from the Oort cloud started "At least a million years ago." So I'm going to edit "many thousand years later" to "several million years later". In other news, I recently played "Das Rad" (http://www.youtube.com/watch?v=n-7y3B8DjGw) for my kids and this comic really reminded me of that Oscar-nominated short. I hate lichen!  :-) Tovodeverett (talk) 15:10, 29 November 2013 (UTC)


What's with the "Several million years later" context in the transcription?!? The distances might be vast and all, but i doubt the timeframe is that long... -- 173.245.51.210

See the comment right above yours. Diszy (talk) 18:03, 29 November 2013 (UTC)
You are discussing editorial elements included in the transcription that have no relationship to the original comic. Regardless of any implied passage of time the comic does not directly state a time-frame that passes and the transcript should only include information contained in the original comic. Any discussion of time-frame should take place in the explanation. The panels imply a pause of unspecific time. The transcript should read the same. Mrarch (talk) 16:18, 2 December 2013 (UTC)

A comic I did predict yesterday

Uhhh, while I observed that close encounter of ISON at the sun yesterday live I was sure Randall would do a comic on this matter. And he did. That's just funny for me. --Dgbrt (talk) 21:28, 29 November 2013 (UTC)

When is a comet a comet?

Wikipedia says "A comet is an icy small Solar System body that, when passing close to the Sun, heats up and begins to outgas, displaying a visible atmosphere or coma, and sometimes also a tail." I see no clear suggestion on Wikipedia that a small Solar System body might change from being an asteroid to being a comet each time it passes by the sun and starts to outgas. It seems to me that SSSB's that contain ices and other volatiles that would outgas given enough heat are comets, but I haven't seen that question really addressed clearly by any authoritative sources. For now I'm switching the references to distant comets from "asteroid" to "comet nucleus", which is used on wikipedia and seems like a neutral term for an icy object that would show a cometary atmosphere and tail when close to the sun. Also, the oort cloud is hypothesized to have both a spherical and a disk-like structure, and is part of the solar system. Please discuss further related changes here. Thanks! Nealmcb (talk) 16:34, 1 December 2013 (UTC)

The most false understanding is: A comet is a dirty snowball. In fact it's just a snowy rock, most of it is still rock, otherwise it would break up at a distance between Earth and Venus. And all the frozen gases are not only H2O. Furthermore a comet is a comet when we can see its shape, unless that tail is shown it's just a small object at our solar system, not more.--Dgbrt (talk) 22:17, 1 December 2013 (UTC)
The wikipedia references in the article talk of objects out in the Oort cloud as "comet nuclei". Unless you can find better sources, that's what we should go with. Nealmcb (talk) 14:56, 2 December 2013 (UTC)

Diameter of the sun: 1,391,000 km

Distance of ISON from sun at perihelion: 1,860,000 km

ISON went within one sun diameter

One of the above statements is false. All are in the explanation. --Zagorath (talk) 18:37, 2 December 2013 (UTC)


Nothing is false. ISON's distance is from the CENTER of the sun. ISON went within one sun diameter distance from the SURFACE. So ISON went closer than 1.5 diameters from the center. 1,391,000 * 1.5 = 2,086,500 which is more than 1,860,000. --173.245.63.198 19:28, 2 December 2013 (UTC)


A definition for a comet doesn't exist

I did mark the comic as incomplete again. We have to explain that there is no real definition for comets.

  • Look at this really big one: 2060 Chiron.
  • Wiktionary says: "A celestial body consisting mainly of ice, dust and gas in a (usually very eccentric) orbit around the Sun and having a "tail" of matter blown back from it by the solar wind as it approaches the Sun." [1]
  • IAU says: "All other objects (except planets and dwarf planets), except satellites, orbiting the Sun shall be referred to collectively as Small Solar-System Bodies". Look for RESOLUTION 5A
  • And an interesting blog entry at livejournal: What's the difference between a comet and a planet?

--Dgbrt (talk) 20:19, 2 December 2013 (UTC)

Maybe the incomplete tag could be removed again, but this is not my decision because there are maybe still some questions. --Dgbrt (talk) 22:37, 3 December 2013 (UTC)