Talk:Meteorite

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Wikipedia Version 1.0 Editorial Team
WikiProject icon This article has been reviewed by the Version 1.0 Editorial Team.
 
Note icon
This article is included in the 2006 Wikipedia CD Selection, or is a candidate for inclusion in the next version. Please maintain high quality standards and, if possible, stick to GFDL-compatible images.
 ???  This article has not yet received a rating on the quality scale.
WikiProject Geology / Meteorites  (Rated B-class, High-importance)
WikiProject icon Meteorite is part of WikiProject Geology, an attempt at creating a standardized, informative, comprehensive and easy-to-use geology resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.
B-Class article B  This article has been rated as B-Class on the project's quality scale.
 High  This article has been rated as High-importance on the project's importance scale.
Taskforce icon
This article is supported by the Meteorites task force (marked as Top-importance).
 
Note icon
This article has been marked as needing an infobox.

How can we classify the meteorites with Soil Mechanics(like as USCS)?[edit]

I want to know about that subject. And, I want to sort them in usable order. — Preceding unsigned comment added by 203.252.176.86 (talk) 07:05, 1 June 2011 (UTC)

Headline: Watch a Meteor Explode on the Moon, Resulting in the ‘Brightest Impact’ in Recorded History. Feb. 24, 2014 7:00pm Liz Klimas

The article has a four-minute video and explanations of this September 11, 2013, event on the moon. — FYI, Charles Edwin Shipp (talk) 20:42, 25 February 2014 (UTC)

Probability of meteorite strike on Earth surface[edit]

The article says that the probability is the same over the surface of the Earth. Since an object in space will be attracted by the Sun's gravity, it seems that the probability of an Earth-surface strike would be higher near the equator.Jarhed (talk) 14:57, 10 August 2011 (UTC)

Quantitative estimates of number and mass/size distribution?[edit]

It would be very nice to have some quantitative estimates here about the rates of meteor falls as a function of mass and size. The current text says ~500 meteorites per year, but no reference is given, and there is no information about the size distribution. I think there must be estimates in the professional literature, probably common knowledge to experts working in the field. Wwheaton (talk) 03:29, 14 February 2012 (UTC)

Meteorite finds in China[edit]

There are several articles online about a recent find in western China; e.g. http://www.space.com/12416-giant-meteorite-china-discovery.html

Also, there are claims in China of an enormous and ancient meteorite near Shenyang, Liaoning, China, but these seem specious.
e.g.
http://en.wikipedia.org/wiki/Shenyang#Attractions
http://www.shenyang.world-guides.com/shenyang_attractions.html
the only picture I've found of the 'meteorite' is at http://www.flickr.com/photos/31300965@N04/4837740358/ — Preceding unsigned comment added by Bobbozzo (talkcontribs) 18:27, 18 March 2012 (UTC)

hundreds of meters in diameter or more,[edit]

or should we be using proper SI spelling? Metre, not meter. 68.71.8.95 (talk) 01:25, 29 July 2012 (UTC)

"proper"? No, there are two proper spellings in English. see Metre. — Preceding unsigned comment added by 202.179.19.24 (talk) 10:42, 15 February 2013 (UTC)
It depends on whether this article was started in American English or British. Kortoso (talk) 18:40, 6 September 2013 (UTC)

"Frosty" meteorite[edit]

This is from a single second-hand account from 1917 ("A New Meteorite", Popular Astronomy, Vol. 25, 1917, p.634; Ward, H. L.).

Absent other evidence, I would call it a myth. Kortoso (talk) 18:08, 6 September 2013 (UTC)

We talked about this in a planetology lecture I took at the university. Rocks are bad heat conductors and their passage through the atmosphere is relatively short. For bigger meteorites only the surface is heated, while the core maintains the temperature of outer space. After hitting the ground the heat from the surface and later the heat from the air is used to warm the interior of the meteorite. For a limited amount of time the meteorite could be cold enough to form an ice crust. - All of that seems reasonably likely, but I also don't have a peer-reviewed source for this, so there is a danger of this being an urban myth that has made its way into university courses. I will try to investigate this a little more. At least the possibility of this happening could be shown by numerical modelling. --Tobias1984 (talk) 19:18, 6 September 2013 (UTC)
There are some websites that mention meteorites being cold ([1], [2]) and one publication talking about the possibility of extraterrestrial ice being preserved in antarctic meteorites ([3]). --Tobias1984 (talk) 19:45, 6 September 2013 (UTC)
They are most likely using Wikipedia as a reference. Time to stop spreading rumors. Kortoso (talk) 01:09, 8 October 2013 (UTC)
I don't concur with you on that, Kortoso. The references in ([4]) are clearly scientific in a reputable journal. I didn't see any echoes of WP in the other, less reputable, citations, either. User:HopsonRoad 03:33, 8 October 2013 (UTC)
The Cornell site says "unfortunately, there really aren't very many meteors that are picked up directly after they've fallen, so it's hard to do good statistics on which ones are hot or cold"; unfortunately their FAQ, which I assume once had the answer, is a dead Earthlink page.
The Bad Astronomy site repeats the "many meteorites" line, without being specific. If there were many, then there should be at least one concrete example. A "mention" does not constitute proof; otherwise we'd be dancing with unicorns. :)
I don't speak Hungarian and I have never heard of the cited journal, so I have to take your word for it that this is "clearly scientific" and "reputable". However, the authors begin by saying that "...we do not observe ices in oncoming meteorites" and "now one can see that indeed the reliable observation of an icy meteorite is difficult." Then they point to two very old examples in Hungary (1875) and Punjab, (1860). Based on the paucity of recent scientific observations, if "frosty meteorites" exist, then they are as rare as ball lightning. I remain unconvinced. Kortoso (talk)
I found the "Punjab" meteorite discussed in detail here: [5] Apparently, it was a victim of an error in translation; it was seen coming from the north, and was not actually frozen. Kortoso (talk)
I really seems like it would be time to make a critical scientific review of these questions (Are some meteorites cold after impact (to the point where humidity freezes on the surface of the meteorite)? Can extraterrestrial ice survive atmospheric passage and be preserved under the condition that the meteorite impacts in a polar region?). I will try to contact the editor of Meteoritical Bulletin. --Tobias1984 (talk) 18:04, 7 November 2013 (UTC)
Thank you. We often assume that "space is cold" and that every asteroid is at absolute zero. In fact, a small rock in the vacuum of near-Earth space will be hot on one side (from unshielded solar radiation) and cold on the other. And these rocks are often composed of iron and nickel, which are actually fairly good conductors of heat. Not great, but nobody's making insulation with that material... So I wouldn't expect a random rock in space to be frozen. Kortoso (talk) 18:13, 7 November 2013 (UTC)
More: Although these netizens think that they are proving the existence of cold meteorites, read the actual account of this incident from Forest City, Iowa in 1890: [6] An unnamed boy picked up a rock: how did he know that it was the meteorite? Is the "meteorite" in a public collection so it can be confirmed? We don't even know the boy's name? This is not a scientifically verifiable resource either. Kortoso (talk)
Asteroid facts: 433_Eros: "The daytime temperature on Eros can reach about 100°C at perihelion. Nighttime measurements fall near -150°C."
I am not sure what you are trying to say with the lower paragraph, so I have to guess. A meteorite resulting from 433 Eros would still be overall cold, because the heating effect probably drops to zero within the first centimeter depth. Also any existing ice would probably be safely stored in fluid inclusions. Regarding the first paragraph: You are right about that source being very anecdotal. It just might be that there is no reputable scientific study about this topic. Or at least I couldn't yet find one, and my library-vpn doesn't cover that many journals. --Tobias1984 (talk) 08:21, 8 November 2013 (UTC)
Just trying to say it would be boiling hot on the other side. I'm assuming that we are talking about meteorites and not comets. Depending on the size of the object, the hot side and the cold side would tend to moderate the overall temp, especially since it would be expected to tumble in space for eons. I'm not sure where I see anyone testing this; I don't see where you get the assumption about "first centimeter depth". Yes, it's remarkable how many of our supposedly reliable sources are not checking the primary sources. I'm sure that, as in any science, the truth will be revealed given time and persistence. Kortoso (talk) 17:27, 8 November 2013 (UTC)

Okay, I have left this on the shelf for long enough. Nobody has come back with any proof other than century-old hearsay. I'm removing the mention of the "frosty" meteorite. If any better citations (besides circular references to this page!), then we can revisit this. Fair enough? Kortoso (talk) 19:23, 21 March 2014 (UTC)

@Kortoso: - I agree. (I missed the watchlist notification). --Tobias1984 (talk) 10:33, 10 May 2014 (UTC)

"Cosmic velocity"?[edit]

Use of this term is not clear. Is this "first cosmic velocity"? Should have a link to this then: https://en.wikipedia.org/wiki/Escape_velocity Kortoso (talk) 19:06, 6 September 2013 (UTC)

This may be a dumb question but....[edit]

Do meteors and meteorites or anything in that general category ever cause fires when they land on earth? I read that they are all cold to the touch when they land. Is that true? Perhaps that information should be incorporated into this article a/o the one on meteors? Thank you very much. Risssa (talk) 00:34, 9 October 2013 (UTC)

Sources:
71.139.148.134 (talk) 01:10, 9 October 2013 (UTC)