Wikijunior talk:Solar System/Oort Cloud

• w:Oort_cloud
• w:90377_Sedna

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Not to knock the work done here but is the oort cloud really appropriate for what is after all a basic intro to the sloar system. I've never heard of it before, and since there seems to be some debate if it is part of the keppler belt or not, maybe it should be cut... The bellman 04:51, 8 Jun 2005 (UTC)

Minor clarification

Current Text: "It is believed that most comets originally were in the Oort Cloud before "falling" into the Sun."

I think falling "into" the Sun might not be what we're looking for - would falling "toward" the Sun be better? Falling into the Sun implies a fiery end for the comet.

While I think that the toward is perhaps more correct, "falling into" the sun does indeed happen. In fact, SOHO has seen several with a very fiery end as they go right into the photosphere (with a strong assumption that they don't make it back out). Perhaps some clarification on the comet page of both types? I was just trying to put some content in for this page, so don't worry about bruising my ego to make it more correct.Rob Horning 06:32, 24 Jun 2005 (UTC)

Is this really necessary?

The Wikipedia article admits that "The Oort cloud ... is a postulated spherical cloud of comets..." and "Although no direct observations have been made of such a cloud, it is believed to be the source of most or all comets entering the inner solar system...". Is there any evidence that the Oort cloud even exists (besides the fact that comets enter the inner solar system)? And if there isn't, or if the only evidence is one comet that isn't even close to far enough away, why teach this to kids? And why call this armchair speculation science? - SamE 14:32, 7 August 2005 (UTC)

There is large amount of evidence to support the Oort cloud, Hubble Space Telescope has seen large amounts of very small (20 km or so) objects in the far outer solar system. N1person 21:26, 19 December 2005 (UTC)

No there is no evidence for the oort cloud, it has never been observed, but guess what, WITHOUT the oort cloud evolution is impossible, they will make it there i am sure. I am sure the vatican would stand up to any silly arguments put forward by nasa about a oort cloud, even a quote from the author, i now doubt the oort cloud exists as there is not a shred of evidence for its existance. Stop teaching junk to kids and brain washing them with propogander nonsence.

Wikipedia:90377 Sedna is plenty far enough away. (What about Wikipedia:50000 Quaoar ?). Apparently other smaller objects are not newsworthy enough to make my newspaper. Do you have a reference for any observations of these small objects? The Kuiper Belt and The Oort Cloud seems to imply that Hubble has only seen 1 such object. Have there been more discoveries (by Hubble or anything else) since that was written? There are quite a few obstinate, stubborn people who prefer links and literature references over "the evidence exists, trust me!" :-). --DavidCary 21:10, 16 January 2006 (UTC)

I think the problem here is that any observation of objects as small as a typical comet is not likely to occur until after the object becomes a comet and enters the inner Solar System. The objective scientific evidence is comparing the frequence of comets over the past several centuries, especially records of comets by Chinese astronomers over the past three millenia, and extrapolating the number of objects that would hypothetically be needed in the Oort cloud to produce that many comets with the seemingly consistant frequency of these cometary appearances. Cometary infalls measured by SOHO have given another much larger set of datapoints for smaller objects that are not normally seen by terrestrial telescopes simply because they are so tiny that normally they wouldn't even be seen even if passing between the Earth and the Moon. As for other Kuiper Belt objects, there have been many, but keep in mind that objects like Sedna and Quaoar have to be large enough to be resolved with current telescopes simply because they emit so little light by reflection that there is hardly anything at all that can be measured at all. Pluto was right at the resolution limits of telescopes at the time of Tombaugh, and had it been any smaller Pluto would not have been discovered at all.

If you want to see a current list of confirmed asteroids, please look at the Minor Planet Center for current updates. This site is the "official" organization that desinates any asteroid discoveries and is the central clearing house for any current asteroid observations, including Kuiper objects. Of particular interest may be the plot of Kuiper Belt objects which show a large number beyond Neptune. --Rob Horning 01:51, 17 January 2006 (UTC)

Passing stars?

Reading about passing stars makes me very curious about which ones just passed our solar system given the relative stable positions of the stars in space? My suggestion is that someone will come up with a better explanation or point out these passing stars please. —Preceding unsigned comment added by IArnold (discuss • contribs) 09:09, 1 March 2011