# Talk:Meteorite

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## How can we classify the meteorites with Soil Mechanics(like as USCS)?

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

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)

The diameter of the Earth is negligible compared to the vertical cross section / density of material in our solar system. The other planets deviate by between ~1° and ~6° from the plane defined by the Earth's orbit. If you use simple trigonometry, at Mercury's orbital radius of 0.387 AU, a 1° deviation from the orbital plane of Earth would mean that Mercury lies 628,225 miles off of that plane. At the asteroid belt, a 1° deviation from the ecliptic would result in a vertical discrepancy of 5,200,000 miles. The Earth is only ~8,000 miles across. Astronomical distances are a lot bigger than the Earth. -Meteoritekid (talk) 20:12, 21 October 2015 (UTC)

## Quantitative estimates of number and mass/size distribution?

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

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,

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

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"?

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....

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)

MansourJE (talk) 14:58, 17 March 2015 (UTC)

## Origin of minerals in our solar system

Research groups have found that rotating or swirling of unknown parts of gas and dust. (It is known as protoplanetary disk), gives rise to planets in our solar system. Complete information can be studied here:

http://phys.org/news/2015-03-clues-dawn-solar.html

MansourJE (talk) 18:52 17 March 2015 (UTC)

## Suggestion - say something about history of understanding of meteorite and thunderstones

Just a thought, it might be nice to have a section on ancient beliefs that meteorites came from thunderstorms or from volanoes - which were held by scientists also right until the late eighteenth century. And Aristotle's belief that a meteorite was lifted by a strong wind and then dropped.

And to mention Ernst Friedrick Chladni who first put forward the theory that the meteorites came from fireballs, in a book "On the Origin of the Mass of Iron Discovered by Pallas and Others Similar to It, and on Some Natural Phenomena Related to Them"

There's a summary here The Impossible Rocks that Fell from the Sky

And wikipedia has a section on his book here: Ernst_Chladni#Meteorites

Robert Walker (talk) 10:33, 28 August 2015 (UTC)

## Killed by Meteorite?

'Meteorite' kills man in Tamil Nadu state, Indian authorities say ABC.net.au 220 of Borg 04:14, 9 February 2016 (UTC)

220 of Borg, I came to this article as I was wondering if this incident had been confirmed or not. I was surprised there's nothing in the article about it. I found that the collage has release a report at http://www.nct.ac.in/meteorite_fall.html That page is not dated though the images have Feb 13, 2016 11:18 (UTC) time stamps and the page has a Feb 15, 2016 05:09 (UTC) time stamp. The page mentions that a "detailed scientific study report will be published shortly".
The report includes a picture of a black object that appears to be iron filings coating a magnet with a paperweight in the background that gives a sense of scale. It's odd that the filings are of a very consistent color. There's another picture of a black object recovered from the roof of a nearby building. There's no scale on this picture but as the article mentions searching the roof using handheld magnets I suspect the latter object is quite small.
The page also mentioned "The news reported by CNN today (Feb 10, 2016)". The CNN article is http://www.cnn.com/2016/02/10/asia/india-meteorite-man-killed/
I'm personally skeptical that it was a meteorite and am disappointed that there seemed to be no testing for explosives, no pictures, nor testing, nor detailed description of the victims or their clothing, no pictures nor testing of surrounding buildings, trees, or other objects. There were no reports of sonic booms, no mention of smells, and there were no sighting or pictures of smoke trails in the sky.
The two injured people seem to be gardeners. A picture of the event site shows what appears to be a burn barrel where something blew up inside the barrel. Were they burning something in the barrel at the time?
This is an early article that has an item that supports the flying object theory with "investigators suspect a 'drone-like' flying object responsible for the incident." Unfortunately, there seem to be no bystander reports from anyone that saw the object.
The Indian one was shown to be very unlikely to be a meteorite Meteorite not responsible for killing man in India: NASA Robert Walker (talk) 07:29, 13 January 2017 (UTC)
FWIW, a search of Wikipedia finds:
• Sylacauga (meteorite) mentions "A manuscript published at Tortona, Italy, in 1677 tells of a Milanese friar who was killed by a meteorite. In 1992 a small meteorite fragment (3 g) hit a young Ugandan boy in Mbale, but it had been slowed down by a tree and did not cause any injury."
• Impact event mentions "A Chinese record states that 10,000 people were killed in Shanxi Province in 1490 by a hail of "falling stones"; some astronomers hypothesize that this may describe an actual meteorite fall, although they find the number of deaths implausible." (I fixed this up to link to the next article)
• 1490 Ch'ing-yang event results in a reported 10,000 killed by falling stones.
--Marc Kupper|talk 21:40, 26 February 2016 (UTC)
Never seen a furry meteorite before. 'Death by meteorite' seems rather dubious now. 220 of Borg 01:19, 29 February 2016 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── There are several accounts of deaths. Even in recent times. Two people died in the Tunguska impact - there were some reindeer herders sleeping close to ground zero. One was thrown into a tree and later died of his injuries. Another died of shock. Another bit of his tongue and many were bruised and injured. Several hundred reindeer were also killed. There is a more recent report also, * 1929 December 8. Meteorite hits a bridal party and kills one person in Zvezvan Yugoslavia

Papers here which give further cites to follow up: Human casualties in impact events [7] and here: Meteorite falls in China and some related human casualty events [8]

FWIW I combined the reports in the two papers and made a consecutive list here: [9]

Perhaps it might be an idea to do a similar list somewhere in Wikipedia? Maybe a new short article? Of course not cite me as a source, please don't do that, but make one from scratch from the citations I give which is to say basically those two papers plus Lewis’s book Rain Of Iron And Ice: The Very Real Threat Of Comet And Asteroid Bombardment which I have ordered but don't have yet so for now am relying on a quote from it by someone else [10] I may find more. Robert Walker (talk) 07:25, 13 January 2017 (UTC)

There's also a long list by the International Comet Quarterly with cites here [11] which includes damage to buildings and other structures as well as deaths and injuries to people.

Robert Walker (talk) 07:33, 13 January 2017 (UTC)

## Comic about identifying meteorites

In case anyone would like to incorporate some pop culture and info about identifying meteorites—

xkcd has a recent comic about the appeal and unlikeliness of identifying a meteorite. A mention of it could be a nice addition to the article, in the finds section or in a popular culture section, for instance. The comic also mentions a more helpful version of the chart and "Note: Jolyon, founder of mindat.org, made a similar chart way before me!" —Verbistheword (talk) 19:21, 7 September 2016 (UTC)

## Los Angeles Meteorite—unclear provenance

‎Meteoritekid made this good-faith edit with the edit comment, "The source also does not state that he found the stone: the claim you're making is unsubstantiated", which suggests that "the Los Angeles meteorite, a Martian meteorite that was found by an unidentified mineral collector and later purchased and identified by Robert Verish". The previous version said that the meteorite was "a Martian meteorite that was found by Robert Verish".

The source, Meteoritical Bulletin entry for Los Angeles meteorite, says "Martian basalt (shergottite) Two stones, weighing 452.6 and 245.4 g, respectively, were found by Bob Verish in his backyard while he was cleaning out a box of rocks that was part of his rock collection. The specimens may have been collected ~ 20 years ago in the Mojave Desert.", but does not mention anyone other than Verish or any purchase. Am I missing something? The phrase "his rock collection" suggests that he found the specimen. I don't see support in the source for the claim that it "was found by an unidentified mineral collector and later purchased and identified by Robert Verish". What do others think?

I suggest that the entry simply say, "the Los Angeles meteorite, that was identified by Robert Verish as being Martian in origin", if it's unclear whether Verish or someone else actually found the specimen. Sincerely, User:HopsonRoad 23:37, 25 May 2017 (UTC)

I'd treat this remark as a "citation needed" and revert and add this extra cite - it's from JPL so reasonable support that it was indeed found by Bob Verish. [12]. See also the separate Los Angeles (meteorite) article which has it formatted as a ref. Robert Walker (talk) 23:52, 25 May 2017 (UTC)

## Passage and impact or just passage?

The wording of the lead sentence is a bit confusing:

A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the Earth's atmosphere and impact with the Earth's surface or that of another planet.

It suggests that meteors that reach the planet's surface but don't survive the impact aren't meteorites. What does "survive" mean in this context? If the object shatters, are the pieces not meteorites or meteorite fragments? According to reliable sources (e.g., 1 2 3), the suitability of the -ite suffix hinges on the object's reaching the surface (i.e., not being burned up in the atmosphere), not whatever happens on impact. I'd be bold but would first rather hear from a regular article watcher or two. RivertorchFIREWATER 15:34, 23 October 2017 (UTC)

And there's a related problem:

Meteorites that survive atmospheric entry and impact vary greatly in size.

Again, as I understand the definition based on the reliable sources I linked above, if it doesn't survive atmospheric entry, it technically is not a meteorite. I've gone ahead and made some changes based on my comments here. RivertorchFIREWATER 03:37, 7 November 2017 (UTC)