Talk:Meteoroid/Archive 1

Archive 1

"Burn up in the atmosphere"

That, or something like it, needs to be in the opening paragraph. It's implied that some survive the trip through the atmosphere, but it's never bluntly said that the friction with the atmosphere heats them up and most of them melt. -Anon 12.202.43.103 (talk) 01:36, 11 March 2009 (UTC)

Is this line correct?

hat an object must be about 50 m across before it can survive atmospheric entry[2], this means terrestrial meteo "Oddly enough, because it is thought trites never come from meteoroids."

50 meters? should this be 50 millimeters? —Preceding unsigned comment added by 68.122.74.140 (talk • contribs)

I'm not sure whether it's correct or not, but 50 mm seems a bit small to me. Mikker ^(...) 01:42, 13 December 2006 (UTC)

I think 50mm is more correct - I think I've seen the figure 2 feet depending on what it is made of. I've also heard basketball sized objects could make it to the ground.--Smkolins 17:20, 22 March 2007 (UTC)

I think that 50 meters should be correct; we need an outside source. None of us knows what's really going on. {Slash-|-Talk} 17:27, 29 April 2007 (UTC)

Here's a source: Bland and Artemieva (2006) The rate of small impacts on Earth. Meteoritics & Planetary Science 41, 607–631. Most stony meteorites come from small objects, meter-sized objects or less. Larger objects get disrupted in the atmosphere and don't impact the surface, unless they are really big and can cause hypervelocity impact craters. This is where the 50 m number fits in. --JeffG 19:36, 29 April 2007 (UTC)

It's dependent upon too many factors to make such arbitrary statements. Such things as mass, composition, velocity, angle-of-entry must be taken into account. 210.54.245.44 01:59, 17 August 2007 (UTC)

Merge proposal

There is considerable overlap between these articles. There is little extra information it the meteor and bolide articles so it would be logical to merge them into this article. (I don't suggest the same for meteorite because that article is fairly long and stands alone.) Rsduhamel 16:44, 18 March 2007 (UTC)

Went ahead and did the first merge, except I thought it was more appropriate to merge meteor into meteoroid. Rsduhamel 21:24, 18 March 2007 (UTC)

Found a similar situation with micrometeoroid. Probably should be merged into meteoroid. Rsduhamel 05:13, 19 March 2007 (UTC)

A micrometeoroid is a meteoroid smaller than about 0.1 mm in size. It is also a word

synomous in the planetary astronomy community with cosmic dust. Merging is not a good idea. I suggest to look [[1]] for a clarification of definitions. Amara 20:51, 11 June 2007 (UTC)

merger seems awkward

I know that meteoroids are the thing and meteors are an ephemeral phenomena caused by meteoroids - but everyone know meteors and wold be confused, I think, by searching for meteors and coming to a meteoroid page. Seems a bit coercive - I'd rather see the meteoroid redirected to the meteor page--Smkolins 04:39, 21 March 2007 (UTC)

Since all meteors are meteoroids and all meteoroids are not meteors the requrested move page editors seem to prefer the corrent organization.--Smkolins 10:18, 16 April 2007 (UTC)

Definition of a fireball

I can't find an attributable quote from the IAU as to what a fireball is. Some quote it as "a meteor brighter than any of the planets" (which sounds like something they would say) and others as "a meteor brighter than magnitude -4" (which essentially says the same thing). Can someone find the real dope on this? Rsduhamel 18:46, 28 March 2007 (UTC)

head-on collisions

"Together with the Earth's orbital motion of 18 miles per second (29 km per second) speeds can reach 44 miles per second (71 kilometers per second) in head-on collisions. This means the meteor would also be in a retrograde orbit and a daylight (or near daylight) event as the Earth orbits in the direction of east a dawn"

This doesn't appear to make any sense to me... surely the direction of the Earth's orbit is pretty irrelevant? Anyway, wouldn't east at dawn be directly towards the Sun? So 3 things this section isn't making very clear: what is the actual direction of Earth's orbit, how does it affect the time of day at which a head-on collision with a meteor can occur and why does this mean that a meteorite can't strike at night? Sk8a H8a 06:38, 29 March 2007 (UTC)

I agree with the part about east at dawn being towards the sun rather than the direction of the orbit. But no the direction of the earth's motion isn't irrelevant - the question is how do you get the spread of meteoroid speeds - meteors coming from the night side have to play some kind of catch up. But the proper direction could be described as "down" at the equator at dawn, or east at noon at the equator. I think some of the rest of the variability of the meteoroid speeds comes from how far up the solar system the meteoroids come from. Most are claimed to come from either the asteroid belt or from comet evaporation. If they come from the asteroid belt that's a pretty defined area even if collisions that release them would kick them around some. If they come from comets it should increase their potential energy being converted to kinetic energy but most of the gravity well they are accelerating in is from nearer the sun. But it would be nice to be able to refer to some numbers on this. I'll check the east at dawn bit in the article.--Smkolins 10:27, 16 April 2007 (UTC)

All I could find on the net for the speeds is a quote in a discussion area - plenty of details but not reference-able easily in wikipedia - see[2] but here's a calculation of meteorite velocities [3]. Still worth doing more searching....--Smkolins 10:47, 16 April 2007 (UTC)

Hmmm. It appears that quite a few people noticed these horrible inaccuracies and wrote about them extensively on the talk page. Nice work, guys, but it is now June and those errors regarding earth's orbital motion were STILL IN THE TEXT until I corrected them today. That is far too long for inaccuracies to linger in an encyclopedic entry. Here is a proposal: next time you see something that is blatantly wrong in an article, how about fixing the error, instead of engaging in masturbatory actions on the talk page which, after two months, have not magically fixed the error on the REAL page, the one that, say, a young child just learning about the geometry of the solar system will dutifully copy word for word into its report on the solar system, only to be docked by the teacher for the gross inaccuracies contained within. If anyone needs a refresher on basic solar system geometry, why not google it? It's pretty easy to do. Just gaze for a brief moment at a simple diagram of the earth in orbit around the sun and you will see the truth of the situation. User:Tarotcards

Bolide definition

The original quote to a USGS web site was ...."an extraterrestrial body in the 1-10-km size range, which impacts the earth at velocities of literally faster than a speeding bullet (20-70 km/sec = Mach 75), explodes upon impact, and creates a large crater". While an accurate quote, the numbers given are nonsense and do not represent cutoffs that any cratering geologist, including those in the USGS, would use (eg 20 km/sec is actually faster than the average meteorite impact velocity). I changed the quote to the next sentence in the original source that far more accurately represents how cratering geologists actually use the term bolide. —The preceding unsigned comment was added by Zamphuor (talk • contribs) 02:13, 1 April 2007 (UTC). Whoops, forgot to sign. --Zamphuor 02:15, 1 April 2007 (UTC)

Ionization trail

There is a large quantity of uncited, unscientific information in this sub-section. Rather than remove it outright, I will tag it and hope another editor can verify these claims. I believe much of the material in that section is pseudoscience, especially in relation to "secure communications." Nimur 18:25, 21 May 2007 (UTC)

a simple google search for "meteor scatter secure communications" will reveal material that supports the information presented, including IEEE papers. it is not pseudoscience. here's a primer and one of the first results to come up:http://www.uksmg.org/deadband.htm. you can safely remove the tag. --Tase 13:40, 22 May 2007 (UTC)

Beliefs

Hm, I have come across some beliefs for shooting stars, one of which says that a shooting star resembles the passing of a person. Wonder if it is related and can be put on this page. --121.6.64.153 13:59, 15 August 2007 (UTC)

Mystery illness strikes after meteorite hits Peruvian village

Ok, I am not a Wikipedian anymore, but this may be worthy of some mention? We should follow this story for a week to see where it leads, and write a paragraph. Sounds like a moderately big meteor strike.

The disease symptoms may be due to (a) a few people legitimately getting sick due to some kind of fumes from the burning ground/surface of meteror, then followed by local mass hysteria, (b) radiation sickness, as the putative meteor may actually be a Chinese or Russian nuclear powered satellite, or (c) long awaited (better: feared) example of exposure to extraterrestrial bacterial organisms.

Note that (c) is legitimately possible, but also extremely unlikely, as all bacteria/fungi/viruses on Eath thus far studied have been of terrestrial origin. (With the one glaring exception - all life on Earth may originally be of extraterrestrial origin, such as bacteria from Mars meterorites landing here 3 billion years ago. I know that sounds like science-fiction, but it is considered a possibility by expbiologists.) RK 15:35, 18 September 2007 (UTC)

Mystery illness after meteor lands

Meteorite Lands in Puno, Peru Near Bolivia, Citizens Report Radiation Sickness

(LIP-ir) - Peru's Andina News Agency reported today that Puno's Regional Health Directorate sent a group of specialists to the Carancas community in the province of Chucuito near Bolivia to take samples of a meteorite that supposedly landed in the area...

Meteorites lands in Peru, near Bolivia

RK 15:21, 18 September 2007 (UTC)

Detection

Can objects smaller than 50m in orbit around the sun be detected individually? Are the orbits of any known? Are there any swarms that are not associated with meteor showers, or should readers be directed there for a catalog of known meteoroid groups? -- Beland (talk) 07:04, 2 January 2008 (UTC)

Mean free path?

The reference to "mean free path" confused me.

The Mean free path page says "In physics the mean free path of a particle is the average distance covered by a particle (photon, atom or molecule) between subsequent impacts" which is consistent with my understanding.

However, this article says "For bodies with a size scale larger than the atmospheric mean free path (10 cm to several metres)" which suggests the average distance between collisions in the atmosphere (presumably with molecules of air) is as large as several meters. Presumably that's only the case at extremely high altitudes, outside what we usually regard as the edge of the atmosphere.

Is this really what is meant here? Or would it be better to say something like "very much larger than"?

User:Tarotcards, I apologize for not just fixing this problem, but I'm not sure if this suggestion is really better. :-) 67.169.24.155 (talk) 00:18, 7 October 2008 (UTC)

• I agree, it's confusing. It's not clear if "10 cm to several metres" refers to the mean free path (presumably, as you say, in the extremely tenuous upper atmosphere) or to the meteoroid, and if the former why such a wide range should be given, or if the latter why it's felt necessary to give an upper bound at all. Does it just mean "meteoroids larger than 10 cm"? Someone knowledgeable should fix this. 86.133.245.38 (talk) 04:18, 16 January 2009 (UTC).

Meteors and the Origin of Life

If meteors hitting Earth's primordial oceans can be represented by balls of iron and carbon shot into a stew of water and ammonia, then meteor strikes may have triggered the evolution of life.

Proof That Meteors Could Have Sparked Life on Earth NASA Identifies Carbon-rich Molecules In Meteors As The ‘Origin Of Life’

This was not formatted as text. The title of a lay summary does not constitute a statement that should be used as text. Blogs are not reliable sources. It's placement early in the article was disruptive to the flow, just as placing this copy at the top of the talk page was inappropriate. I have done what I can to salvage what you were trying to do. I am not sure this belongs in this article or if it belongs in a related article. Novangelis (talk) 13:19, 16 January 2009 (UTC)

Wishing

I know this is a scientific article but I was wondering it it was OK to include a mention of how urban myth states that one should make a wish when one sees a "shooting star"(ie a meteor)?Loki0115 (talk) 15:24, 20 January 2009 (UTC)

I've broken this off to it's own discussion section. While cultural significance might be worth a mention, any detailed discussion would probably be better off at a poorly developed article, Wish. If you can assemble good sources, this looks like a good opportunity to contribute. Novangelis (talk) 15:34, 20 January 2009 (UTC)

Friction or air-compression

I started wondering when this blog [4] listed meteor heating by friction (as also mentioned in this article) as a myth. Instead it proposes that the compression of the air in front of the meteor causes the heating, roughly in accordance with the gas law. This is mirrored in the section Space_Shuttle_Columbia_disaster#Destruction_during_re-entry where the 8:44 log states that 90% of the heating is due to air compression. EverGreg (talk) 20:12, 24 April 2009 (UTC)

Reading up on this a little, I find it a big subject. A good starting point is probably "Physics of Meteor Flight in the Atmosphere" by Ernst J. Opik. Bascially, direct collisions with air molecules is important for small particles, while the plasma cushion infront of the meteor is important for large ones. Friction can both heat and cool meteors in a sense. But it's difficult to improve on this section of the article without investing a lot of time on the subject. :-/ EverGreg (talk) 13:44, 6 May 2009 (UTC)

I recall reading in one of Phil Plait's books that it is indeed air pressure, and not friction. He also mentions it here on his blog: [5]. Pedipalp (talk) 05:41, 17 August 2009 (UTC)

Where is the second? Why so long

• Why is the second picture of the leder captioned that there might be two meteors in it? The image shows an obvious meteor striking through Earth's atmosphere - where is the second?
• Why has this been captioned with "possibly" since its inclusion in the article in Aug 2007?

71.234.215.133 (talk) 20:45, 11 May 2010 (UTC)

No obvious evidence of a second meteor so changed the caption, thanks for pointing that out. As to why that caption has been there for so long, I guess that the few people that spotted it never got around to correcting it. Mikenorton (talk) 21:49, 11 May 2010 (UTC)

Sound and a question

Some years ago I heard a meteorid myself. It very much resembled a firework (SHSHSHSHSHSHSHSHSHSH!!!!!!!!), and I even heard it hit the ground (WHOOM!).

And I've got a question. Why do they only (or at least mostly) occur at nights? According to me, it cannot be solely due to the fact that their light is too faint against the daylight.80.141.194.91 (talk) 18:35, 10 August 2010 (UTC)

How are meteoroids stopped from hitting hard on the earths surface?

How are meteoroids stopped from hitting hard on the earths surface —Preceding unsigned comment added by 59.183.246.63 (talk) 06:45, 17 October 2010 (UTC)

Please reread the introduction to this article. You'll see that Meteoroids that survive the plunge through the Earth's atmosphere and land on the Earth are called meteorites (click on the link to see that article). Best: HarryZilber (talk) 17:15, 17 October 2010 (UTC)

I think the questions was not what but how.

Meteoroids arrive in the upper atmosphere at a given cosmic velocity: typically 25,000-78,000kph(??? approximate from memory needs to be verified???) This cosmic velocity x mass of the meteoroid = momentum/ kinetic energy which is greatly converted to heat and light energy. Much of the mass is carried off as a molten mist further reducing the speed.

• Previous paragraph unnecessarily wordy. Simpler: "Force of friction slows the incoming meteors." — Preceding unsigned comment added by 77Mike77 (talk • contribs) 14:12, 2 November 2012 (UTC)

The result is both the speed and the mass of the meteoroid is decreasing at an increasing rate. IF the meteoroid is small it will not survive the ablation of entry. Once the speed falls below approximately 4200mph the meteorite stops ablation and incandescence( glowing) . It enters "dark flight" and decelerates to "free fall" velocity. Incandescence cannot continue below approximately 5 miles above sea level. As 95%(???) of the atmosphere lies below 5 miles, the 5 mile mark represents a relatively dense fluid compared to the 120-140 miles of atmosphere the meteoroid has traversed. For most meteoroids under 1 meter at entry, all the cosmic velocity has been depleted at or above by this altitude and the body free falls under normal gravitational acceleration. Depending on initial velocity and mass, can enter dark flight between 100 and 5 miles about sea level. Thus a meteoroid arrives at the ground constrained between 120-400 miles per hour(sorry about the cross use of metric and American measurements) So they do hit the ground hard enough to excavate an "impact pit" which may be none to a few inches to a few feet deep. — Preceding unsigned comment added by Mstreman (talk • contribs) 17:56, 18 September 2011 (UTC)

link rot

This reference can't be called up any more. ^ a b meteorshowersonline.com The Leonids and the Birth of Meteor Astronomy 4.249.63.30 (talk) 17:30, 1 March 2011 (UTC)

People/Objects hit by meteors

I think there is a need for info on people getting hit by it or a link directing to articles that talk about it. Thanks. — Preceding unsigned comment added by 160.109.98.44 (talk) 18:50, 2 August 2011 (UTC)

There are some references to people being struck by meteorites in the article Meteorite. You need to consider that a meteor is simply the visible expression of the passage of a meteoroid through the atmosphere, i.e. the illuminated trail of ionised plasma it leaves behind. In the vast majority of cases, the meteoroid either ablates totally or slows down sufficiently so that it is no longer leaving a plasma trail long before it reaches the surface of the earth. Somewhere I remember reading that even for meteorites reaching the earth's surface intact, the visible meteor (i.e. the plasma trail) always ceases at altitudes greater than 8km (5 miles) - this might be worth including in the article with suitable references. Therefore you cannot possibly be struck by a meteor. Peter b (talk) 21:54, 23 March 2012 (UTC)

The direction the Earth travels in its orbit

I am not sure that I improved the article. The explanation that I wrote is true, but the clause preceding the word as in not logically connected to the second clause. Meteors hit the leading hemisphere of the Earth more frequently than they hit the trailing hemisphere, but they hit both hemispheres night and day. Perhaps the reference to the direction the Earth travels in its orbit should just be dropped. Fartherred (talk) 21:08, 12 September 2011 (UTC)

The direction of travel of earth in orbit and the approach azimuth of the meteoroid has implications for meteoroid survival: at 12 noon the speed of the earth along its orbit (15k/sec?) is added to the speed of the meteor-while at 12 midnight the speed is subtracted. Therefore statistically speaking a meteoroid arriving at night undergoes less ablation and is therefore has a better chance of reaching the ground. I am not sure that the argument is true that meteoroids hit the leading edge more often than the trailing edge. Once a meteoroid comes under the gravitational pull of the earth they are drawn in regardless. Some approaching from the rear can be deflected forward and vice versa. Unless we have a specific citation to the contrary I too think this "fact" should be left out.Mstreman (talk) 17:27, 18 September 2011 (UTC)

Near the equator, it is generally the location with local time of 6 a.m. that is "at the front" and 6 p.m. that is "at the back". However, near the time of the equinoxes it is not so straightforward for locations near the poles; the poles point slightly "forwards" and "backwards" with respect to the direction of travel of the Earth around the Sun. - 86.139.167.126 (talk) 17:23, 25 February 2013 (UTC)

Colors of meteors

The color section is misleading and the caveat of "possible colors" should be revisited. The current spectra listing is for a chem lab and not for meteoroid composition. Meteor color is derived from both the atmosphere and the makeup of the meteoroid. For example copper is not found in meteorites above the rare microscopic occurrence. Nickel emits a green spectra but the Green color from meteors is a combination of magnesium( minor), atmospheric oxygen(Major).

For fodder, here is a draft blurb from a paper I am authoring: ... on to specific spectral emissions, the common emissions for metallic elements in meteors and for atmospheric elements can be seen at. <http://leonid.arc.nasa.gov/meteor.html>

Combinations of the two sources of emissions produce the colors one sees in the fireball. “Colors of meteors: The color of many meteors is caused (sic)by light emitted from excited atoms of various elements in the meteoroid (blue, green, and yellow) plus light emitted by excited atoms and molecules of the air (red). The metal atoms emit light much like in our sodium discharge lamps: sodium (Na) atoms give an orange-yellow light, iron (Fe) atoms a yellow light, magnesium (Mg) a blue-green light, ionized calcium (Ca+) atoms may add a violet hue. Actual spectral captures were rare until recently while. The intensity and therefore detectability with the naked eye is almost nill at distance. At longer distances the light from excited atmospheric gases is the most dominant. Light emitted from excited molecules of atmospheric nitrogen (N2) and oxygen atoms (O2) give a green light initially but change to red/orange as the meteoroid goes deeper into the atmosphere. The meteor color depends on whether the metal atom emissions or the air plasma emissions dominate the eye and that is inversely proportional to the difference“...NASA <http://leonid.arc.nasa.gov/meteor.html>... Mstreman (talk) 13:24, 29 January 2013 (UTC)

Unmerge with meteor

I don't understand why the articles on meteor and meteoroid got merged. These are not the same topic. Meteors can result when large objects pass through the atmosphere, not just small ones. So meteors should not be a subtopic under meteoroids. I suggest unmerging. JeffG (talk) 19:58, 26 December 2011 (UTC)

Thank you for for your suggestion JeffG, however, I must strongly disagree with you. In the lead section it is clearly stated that a meteor is the visible expression of the passage of a meteoroid through the atmosphere. Being inherently related phenomena, I believe they quite appropriately described within the same article. Your argument regarding the size of a meteoroid does not really warrant separating the sections of this article either, because, since there is no general agreed definition in either the astroscience community, nor among amateur astronomers as to precisely what size range constitutes a meteoroid (as discussed in Meteoroid#Meteoroid), it is less confusing for non-experts to find all they need to know about the basics of this topic in the one place. If a particular sub-topic warrants a longer explanation than can be reasonably accommodated within the scope of the parent article, it is common practice to summarise that particular sub-topic within the main article along with a link to the separate more detailed stand-alone main article in its own right e.g. Meteoroid#Meteorite. I'm not sure that the subject Meteoroid#Meteor is sufficiently broad to warrant a separate article. Peter b (talk) 21:28, 23 March 2012 (UTC)

I agree with JeffG. The article, as written, is all about meteors and hardly about meteoroids, apart from some basics. I would advocate for a smaller article after looking over some foreign versions. Meteoroids are a much broader topic than what happens as and after they enter the earth's atmosphere. Also, meteoroids have effects all over the solar system, not just on earth. User:HopsonRoad 03:24, 21 January 2013 (UTC)

FWIW, not wishing to be negative, and having just come to this article to check a fact, I think that the meteor-related articles are among the most disorganised that I have yet encountered on Wikipedia for someone who just wants to know about meteors. This is probably inevitable given that there is a spectrum of phenomena from a faint meteor to a brilliant fireball, but anyone trying to get information about meteors as such will have difficulty in finding it among the several articles on the subject. I can't see what's wrong with having a separate topic on meteors, which is an observable phenomenon that people will want to know more about. There is a separate article on meteor showers, which actually gives more useful information, and there are separate articles on individual showers. In general usage, the term meteor refers to the trail left by cometary dust entering the atmosphere, either as a shower or an individual sporadic particle. The average reader would surely expect to find such an article on Wikipedia, not to have to jump around several related topics. I believe that the larger meteoroids, those of maybe 10 mm and larger but I'm guessing, give rise to fireballs and not to meteors. Having said all that, I am not volunteering to do any work on it!Robin Scagell (talk) 12:54, 23 January 2013 (UTC)

Meteors are caused by (small) meteoroids. Larger Asteroids are more likely to cause a Tunguska event. Meteors come from comet debris and small asteroids. Meteoroids are so small they can only be studied when they are near Earth since they are too faint to detect at other times. -- Kheider (talk) 14:47, 23 January 2013 (UTC)

No Meteors in ISS video

After several viewings, I could not identify any evidence of meteors in the ISS video (Aurora_Australis_2.ogv). There appear to be some instances of other satellites visible early in the clip (i.e. well above the atmosphere in the field of view, and travelling far too slowly to be meteoroids), but no meteors that I can readily determine. Neither does the original source (apparently http://eol.jsc.nasa.gov/Videos/CrewEarthObservationsVideos/) make any mention of meteor trails. If anyone knows at what time during the clip there are unmistakable meteors visible, please mention it in the caption. Otherwise, as interesting as the video clip is, I suggest it be removed in favour of something which unequivocally supports the article topic. Peter b (talk) 04:15, 23 March 2012 (UTC) with subsequent revision Peter b (talk) 20:52, 23 March 2012 (UTC)

I noticed the same thing independently. I went over and over it and the moving dots can be nothing other than satellites. They even appear right when they cross the shadow line just like they do when viewing from the ground. They are also about the same height or above the ISS which is at about 220 miles high, meteors light up at around 40 miles high. The claim that the video has meteors in it is unsupported, uncited, dubious. It's a shame because it's a really really really great video! I LOVED IT! And, it introduced me to that particular series of videos and I am grateful. But unfortunately the video is out of place here. Peter b would have been justified in removing it directly. Now that that there have been no objections in four months since it was brought up, it is even more justified to remove. Sadly, I will do that. ("Sadly" because it is otherwise such a great video.) -- 108.7.241.56 (talk) 16:00, 18 July 2012 (UTC)

A few shooting stars can be seen in this ISS video.

If anyone wants to review the video to see for themselves, here is the video with the original caption. You can also watch it just because it is a great video! The "shooting stars" are actually other satellites. I made the thumbnail smaller, but you can click on it to see larger sizes. 108.7.241.56 (talk) 16:22, 18 July 2012 (UTC)

The streak on the upper right-hand edge of the screen at 1.5 seconds in might be a meteor, but it seems too high and possibly too fast. I don't know what it is. In any case, to say that it absolutely is a meteor is still dubious and also isn't justified by a reliable source like it would be if the original source's description said so. -- 108.7.241.56 (talk) 16:34, 18 July 2012 (UTC)

Boulder-sized

Only just registered with Wiki, so not confident enough to edit articles yet! However, I think the basic description of meteoroid is too vague. How big is a boulder? The International Astronomical Union defines a meteoroid as: "a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom." The Hubble site defines a meteoroid as "a piece of interplanetary matter that is smaller than a kilometer and frequently only millimeters in size." Also, the description of meteor shower needs clarifying. Meteors appearing seconds or minutes apart could be pure coincidence, but frequent meteors appearing from a common point in the sky are obviously linked, and are referred to as a meteor shower. Billrush (talk) 22:51, 23 December 2012 (UTC)

Bill, welcome to Wikipedia and thank you for registering. I do not think there is clear upper limit for the size of a meteoroid. It is much like the grey area of asking when a hill becomes a mountain or a creek becomes a river. The Sutter's Mill meteorite source meteoroid/asteroid was around 3 meters in diameter, the Tunguska event impactor was around 40 meters, and the Arizona meteor crater was caused by a dense-iron impactor about 50 meters in diameter. We are always looking for a better way to word things without losing the casual reader. -- Kheider (talk) 00:27, 24 December 2012 (UTC)

I've briefly expanded the description of meteor shower in the opening paragraph, as it didn't make clear the fact that the meteors in a shower all appear to originate from a single point in the sky, due to them sharing a common origin, usually (or always?) the dust stream from a comet. Billrush (talk) 21:27, 26 December 2012 (UTC)

DELETED MstermanMstreman (talk) 14:33, 28 January 2013 (UTC)

Peter Jenniskens misidentified the Novato meteorite when he first looked at it, he did not misidentify the Sutter's Mill meteorite. What this article needs is more "verifiable" reliable sources, not unreferenced statements/claims. Best estimates for the Tunguska event are now around 40 meters (with an asteroid being somewhat more likely than a comet as the source). The best estimate for Meteor Crater is a 50 meter iron-nickel asteroid. This article also needs a section on dark flight. No cometary meteorites have ever been confirmed because they simply weather very quickly (and will look a lot like terrestrial rocks) if not immediately recovered. -- Kheider (talk) 17:09, 28 January 2013 (UTC)

UPDATE: I have read the revision and other than checking citations and the color chart find noting to add for clarity. I'll leave my comments for a time for reference. Excellent rewrite!

Moving up then back down the learning curve, I have removed/relocated most parts of my earlier brainstorm since it is mostly covered in the proposed revision. What was left over was appended below. The previous post/revision was just a laundry list of topics just from memory which would have been underpinned with citations. I will hence forth stick to specific paragraphs in the revision. I am recovering from a brain injury and can see on some things I am not back to par.

I've seen estimates for Tunguska in the 30 megaton/1200 meter range so to avoid confusion-- avoid specifics/values in this article all together and let their individual articles speak. Both Meteor Crater's and Tunguska's impactors were in the size range of "asteroid". They would have been given an asteroid designation had we discovered them today headed on a non collision course. So it begs if they should be in the meteor or meteoroid wiki articles at all, other than links.

Kevin's statement that the "only reason cometary(shower derived) meteorites have not been found is because of their fast weathering" isn't supported by meteoritical knowledge. Objects moving at cometary speeds simply do not survive stresses/ablation, and their actual occurrence is improbable given they would have to be very large sheds/chunks from the stable long period comets associated with a given shower. That said, we may have in fact have cometary-like meteorites as large chunks of space matter suggesting a comet connection are being recovered almost monthly-- but we don't have any from meteor showers and no radiant fireballs of sufficient size/ magnitude year in and year out.(TMK).(Note: Jennskins has a recent publication on sporadic major disintegration giving rise to comet debris discs but doesn't apply to all comet debris streams)

I raise the meteor shower /non-meteorite connection because every major shower brings forward a slew of meteor-wrongs for identification. It also brings uninformed comments from any psuedo-expert (e.g planetarium gift-shop clerk) the local news crew can ambush. I presume many on that audience would read this article and foreclose this misconception. Perhaps we will see a meteor/meteorite myths section.

REVISED: METEOROID vs ASTEROID: The Hubble Site is likely wrong if it says a kilometer is the largest size meteoroid--There are named asteroids much smaller. I side with Rubin and Grossman on definition(1 meter) but can see that there is no unified agreement as to meteoroid size limits. Frankly, we rarely discuss/use the term "meteoroid" at all --and only because of the former narrow definition of "meteor". "Meteoroids" have never been observed in orbit and are ambiguous prior to their becoming meteorites. I've always thought the definitions/distinctions pedantic and impractical for the average user. If "meteor" becomes all inclusive then "meteoroid" almost goes away except in scientific texts.

POSSIBLE NEW DEFINITION FOR "METEOR" I believe I read that as of the Fall,2012, the International Astronomical Union( IAU) revised the definition of meteor to include the whole phenomena--not just the visible flash of light. If so it would now is now "proper" to talk about a meteor and it meaning the light, sound, meteoroid, etc. It also permits discussion about a meteor's separate features (e.g. trail or train).(I saw a news release but I cannot find verification yet on the IAU web site)

METEOR RELATED TERMS: It goes that we should list/link all meteor descriptive phenomena: train,trail, shock wave/sonic booms, bow wave, point meteor, fireball, bolide, radio meteors, dark flight, incandescent flight, magnitude, electrophonic sounds and etc.

FRICTION VS RAM COMPRESSION: I read in the meteoroid article something about "friction causing a meteor to glow". This is a common misconception. It isn't air friction proper which causes ablation or incandescence. It is the heat liberated by ram compression of the air ahead of the meteoroid.( Citation needed)

METEOR SOCIETIES: This article should include a link to the main world bodies who focus on meteors and meteor observing 1) The American Meteor Society and 2) International Meteor Society. Plus, a paragraph on the history and practice of meteor observing with a link to the fireball reporting form/site of the AMS (American Meteor Society) or the AMS wiki article

METEOR COLOR. The whole topic of meteor color and spectra is complicated As written now it says something about "layering of minerals" but that misconception of my own doing. I think generic verbiage about interaction with the meteor and atmospheric gases may suffice. There is evidence that a fireball color change indicates a deeper penetration in the atmosphere owing to a spectral shift in nitrogen above and below certain elevations.(specifics to follow)

COMETARY VS ASTEROIDAL Meteors: The key information to convey is that one class of meteoroid/meteor can be specifically associated with comets and Annual Meteor Showers.

Meteors of cometary origin which give rise to meteor showers, are very small, grain-sized, meteoroids moving very high speeds. No(cometary) meteorite from a "meteor shower"proper has ever been confirmed. There is some vignette evidence that some of the non-shower related carbonaceous chondrite clans have closely matching spectra. Not to further muddle things, but two of the major annual meteor showers (e.g. one body, inbound and outbound passes = 2 showers) do have a spectra matching an asteroid class and are NOT thought to strictly be of a cometary origin.

Asteroidal Meteors/Sporatics which do have a chance of producing meteorites and are the random intercepts of orbiting asteroidal debris. Technically, we have planetary meteors/meteorites but make no distinction.

REMOVE: Discussion re "fireballs can come from any direction" but tend to survive when approaching 6 o'clock. I would not include this in the article.

RE: Notable/documented fireballs: ADD link Wiki article Meteor Procession aka The Great Meteor Procession.

DOPPLER RADAR: There is a new field of meteor/meteorite study developed by Marc Fries of NASA using US Weather Service radar to compute the trajectory of fireballs. It has facilitated recovery of upwards of 10 meteorites.

SKYCAM NETWORKS:The past decade has seen the rise of formal and informal backyard video installations for the purpose of digitally capturing fireballs for triangulation of the trajectory. There is no wiki article yet on these video cams and network coverage. NASA sponsors and operates one out of Redstone Arsenal, Alabama. The Canadian government has a collaborative union of Gov't, Academic, and private skycam operators.

NASA METEOROID ENVIRONMENTS OFFICE: NASA now has a meteoroid office. One of its charters is/was to disseminate data from Dept of Defense Nuclear Treaty compliance assets ( satellite and infrasonic sensors) in non-classified form. The director is Bill Cooke.

TAXONOMY: The origin and history of the use of the word "meteor" needs inclusion. Mstreman (talk) 12:28, 29 January 2013 (UTC)

• NASA defines a "meteoroid" as a small particle from a comet or asteroid.
• The free dictionary: meteoroids
• Science dictionary: meteoroid
• Infographic: What’s the Difference Between a Comet, Asteroid and Meteor? (Universe Today. February 20, 2013)
• "Meteorite and meteoroid: New comprehensive definitions" (2010)
• "...asteroids are smaller than planets but larger than meteoroids". (Universe Today)

184.158.96.147 (talk) 16:20, 21 February 2013 (UTC)

Re-organization needed

This article is mostly about what happens as meteoroids enter the earth's atmosphere (meteors) and their ultimate state as meteorites and micrometeorites. It is barely about meteoroids, their makeup and composition, their origin, etc. To address the latter, would require citations about samples obtained in space as well as inferences drawn on the origins of meteoroids from the study of meteorites and micrometeorites. I propose the following:

• Promoting subsection "Meteoroid" to a section, which would segue to the successive phenomena of atmospheric entry and post impact.
• Creating a new section on "Meteors", whose subordinate sections would describe the frequency, appearance, sound, history, etc. of observed meteors.
• Creating a new section on "Meteorites and micrometeorites" with links to the main articles and descriptions of what they can tell about meteoroids.

I would expect such a structure to reduce the confusion in the minds of average readers among meteoroid, meteor, and meteorite, which the current article only increases! Sincerely, User:HopsonRoad 15:13, 20 January 2013 (UTC)

I believe that I have made contact with all the correspondents to date on this Talk page to alert them of the proposal. User:HopsonRoad 14:02, 21 January 2013 (UTC)

I have also contacted recent substantive contributors. User:HopsonRoad 21:21, 21 January 2013 (UTC)

Responses

• Why do you want a re-organization when a meteoroid is just a small asteroid? -- Kheider (talk) 15:21, 20 January 2013 (UTC)

Because it's not currently principally about meteoroids--it's about meteors and meteorites, the manifestations of meteoroids intersecting with the earth and its atmosphere. Not all meteoric material is from asteroids. User:HopsonRoad 16:40, 20 January 2013 (UTC)

Hmmm. Just noticed that meteor does re-direct here. -- Kheider (talk) 17:05, 20 January 2013 (UTC)

Yes, the articles were combined, a while back. There is active discussion, above, on that topic. Perhaps if the Meteoroid section is strengthened sufficiently to stand on its own, Meteor could be come an article. I have structured my proposal to allow that. User:HopsonRoad 14:15, 21 January 2013 (UTC)

• A reorganization does make sense. The information about e.g. meteors is very spread out, but should probably be in one section. --Tobias1984 (talk) 08:25, 21 January 2013 (UTC)
• It seems to me that anything written about meteors or meteorites intrinsically also concerns meteoroids. The language refers to these things by different words but that does not make the concepts separate from one another. Having more written about meteors than meteoroids is the result of people seeing meteors and mostly only inferring meteoroids. If the title or lead section could make it more clear that the article is about both of these words that might help. - Fartherred (talk) 23:18, 21 January 2013 (UTC)

Thanks for your comments, Fatherred. I believe that I have done that in my proposed reorganization at User:HopsonRoad/sandbox. I have also incorporated your recent contributions to the article here. Please let me know what you think of the proposed rewrite. Sincerely, User:HopsonRoad 23:49, 21 January 2013 (UTC)

I am not very good at organization. I can hardly tell what changes you make, much less evaluate them. I think I will let others comment on the worth of the changes. - Fartherred (talk) 01:01, 22 January 2013 (UTC)

Mockup of proposed reorganized article

Those who would like to visualize the proposed restructuring may view it in my sandbox, until I do something else there. User:HopsonRoad 23:16, 20 January 2013 (UTC)

Reorganized version implemented

Absent any objections in the discussion, above, I have:

• Brought across the reorganized article. I included two changes that were made to the original version during this discussion period.
• Redirected Meteor, Meteors, Bolide and Superbolide to Meteoroid#Meteor.

User:HopsonRoad 13:05, 22 January 2013 (UTC)

Bolide should point to Meteoroid#Fireball. -- Kheider (talk) 14:10, 22 January 2013 (UTC)

I now see how to do that. I'll take care of it. User:HopsonRoad 14:46, 22 January 2013 (UTC)

I see that you did, already. Thanks! User:HopsonRoad 14:51, 22 January 2013 (UTC)

Meteor that hit Russia today

A Meteor hit Russia today and injured 500 people so far. Lots of INCREDIBLE footage was captured: http://www.youtube.com/watch?v=BcUhQThTiMM

The Chelyabinsk object doesn't fit the cited definitions of a meteoroid because it was too large (latest estimate is 17m diameter). So why is it referred to as a meteoroid?--88.73.133.140 (talk) 13:11, 18 February 2013 (UTC)

It is just the historical usage of the term from an era when the smallest known asteroid was large compared to the Tunguska event impactor. -- Kheider (talk) 13:43, 18 February 2013 (UTC)

That Tunguska event article currently describes the relevant body as a meteoroid, even though its size was "60 to 190 metres". In the very same sentence it also implies that it was either a comet or an asteroid! ("Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.")

Whereas this article currently implies that the maximum size of a meteoroid is 1 m. I looked at the source for this claim, this paper by Rubin & Grossman, and I noted the following passage where they mention a 4 metre object as an example: "Before it impacted the Earth, object 2008 TC3 was approximately 4 m across and was officially classified as an asteroid. It is likely that when smaller interplanetary objects are observed telescopically, they will also be called asteroids, even if they are of sub-meter size. Thus, the boundary between meteoroids and asteroids is soft and will only shrink with improved observational capabilities. For the purposes of the present paper, we adopt 1 m as the minimum asteroid size. We thus differ from Beech and Steel (1995) who suggested a 10 m cutoff between meteoroids and asteroids."

I think the lesson to learn is that categorization is difficult. Perhaps one day someone will come up with new words, whose definitions allow categorization based only on aspects that are important to human understanding of the objects in question. And the old words will be retired.

But for now I would propose that the relevant articles should reflect the uncertainty & imprecision in our current definitions. This article should not state definitively an upper limit for the size of meteoroids, just perhaps mention some of the specific proposals. It certainly shouldn't state that micrometeoroids are smaller than meteoroids while citing the Rubin & Grossman paper (which proposes a definition in which micrometeoroids are a sub-category of meteoroids). The Tunguska event article should probably state that the body was an asteroid or comet, and then mention that it has sometimes been called a meteroid, and explain the uncertainty in the distinction. The Chelyabinsk meteor article should probably state that the body was an asteroid, and then mention that it has sometimes been called a meteroid, and explain the uncertainty in the distinction. Open4D (talk) 14:54, 2 April 2017 (UTC)

Tunguska could easily have been only 30 meters in diameter. Objects less than 35 meters in diameter have been called Meteoroid in the past. Now-a-days meteoroids should refer to objects estimated to be less than a meter across and anything estimated to be larger then 2 meters is an asteroid. A similar question is when does a hill become a mountain? Anyone calling Chelyabinsk a meteoroid is at least 10 years behind the times. -- Kheider (talk) 15:27, 2 April 2017 (UTC)

Add entry times?

This article can add "entry times",

 http://brams.aeronomie.be/img/meteor.gif

to readers undertand the sky observations and the tragetory after explosion.

metre/meter

In countries that actually use the metric (SI) system, the unit is spelled "metre", so I don't see why someone changed this to the US spelling, "meter", given that the US doesn't even use the metric system. Is there a wikipedia guideline about this? (PS I didn't write the article, am just wondering.)77Mike77 (talk) 20:25, 21 February 2013 (UTC)

See Wikipedia:Style#Retaining the existing variety: When no English variety has been established and discussion cannot resolve the issue, the variety used in the first non-stub revision is considered the default. -- Kheider (talk) 20:51, 21 February 2013 (UTC)

Thanks for the clarification.77Mike77 (talk) 00:14, 22 February 2013 (UTC)

In the Netherlands, Belgium (Flanders) and Germany for example, the unit is also spelled as "meter". You ar not going to tell me that these counties do not actually use the metric system. Wikiklaas (talk) 02:50, 22 February 2013 (UTC)

In Canada's public school system we use the international (SI) metric system and use the spelling "meter". Although "metre" is accepted as it the French spelling. BatteryIncluded (talk) 15:30, 22 February 2013 (UTC)

Edit request - Sounds

Article claims "how these sounds could be generated remains...mystery" I think it should be "how these sounds are generated remains..." There are only a couple of ways they could be generated, and unless you are talking about the details, we know what they are. Also, the pressure wave (sonic boom) should not be characterized, imho, as being "delayed" - it propagates as it should through a gradient of compressible fluid, there is no "delay". Finally, the last part confuses the known causes of sound generation, with the unknown. I have no idea if the plasma it speaks about causes a delayed signal, relative to physical propagation of a pressure front, or happens in seconds, milliseconds or microseconds after the visual flare. EMR, once generate, propagates at c, of course. Could you specify what exactly the NASA guys are attempting to explain?173.189.75.50 (talk) 00:51, 14 August 2013 (UTC)

These sounds are not imaginary! I heard a meteor on 12 August, a bright fireball, but dismissed it as my over-active imagination. It was only when I followed a link to the NASA website today that I discovered that other people report these sounds! It sounded like s whoosh combined with a fizz. The sound appeared to exactly coincide with the visibility of the meteor Stub Mandrel (talk) 12:27, 14 August 2017 (UTC)

Meteor definition

Apparently, the word "meteor" can refer either to the light produced by heated particles streaming off the object falling through the atmosphere, or it can refer to the object and the particles. I changed the introduction to use the latter definition because it is more consistent with the article's illustration of the phases: meteoroid->meteor->meteorite. — Preceding unsigned comment added by TundraGreen (talk • contribs) 00:44, 24 February 2014 (UTC)

Colors

The text of the article reads:

Possible colors (and elements producing them) include:

• Orange/yellow (sodium)
• Yellow (iron)
• Blue/green (copper)
• Purple (potassium)
• Red (silicate)

An unknown editor wrote in the text of the article., "The above statement needs a reference, and does not take into account the color produced by the ionization of the gas molecules in the atmosphere, or the red-hue of meteors closer to the horizon." I have transferred that issue here for discussion.

My feeling is that the list is not intended to be comprehensive.User:HopsonRoad 04:36, 24 February 2014 (UTC)

For my masters thesis, I created a laser using low-pressure air pulsed with high voltage: producing a brilliant yellow-green Nitrogen frequency. — Charles Edwin Shipp (talk) 13:27, 27 February 2014 (UTC) — See Nitrogen_laser for operating in the ultraviolet range.

The article now cites a NASA article which talks about:

• Orange-yellow (sodium)
• Yellow (iron)
• Blue-green (magnesium)
• violet (calcium)
• Red (atmospheric nitrogen and oxygen)

User:HopsonRoad 03:38, 28 February 2014 (UTC)

Brightest recorded?

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

• http://www.theblaze.com/stories/2014/02/24/watch-a-meteor-explode-on-the-moon-resulting-in-the-brightest-impact-in-recorded-history/

The article has a four-minute video and explanations of this September 11, 2013, event on the moon. — FYI, Charles Edwin Shipp (talk) 21:36, 25 February 2014 (UTC)

Meteor redirect

As per WP:BRD, the Meteor (disambiguation) redirect is currently found in the Meteoroid#Meteor section, but the top Google and Bing search results for Meteor point to the Meteoroid page. I think it would help readers navigate Wikipedia if the redirect was placed at the top of the article, as supported by WP:HNP. BananaLanguage (talk) 20:29, 10 March 2014 (UTC)

Thanks for that insight, BL. I had in mind entering "meteor" within WP, which takes one to the correct section. Perhaps we should do a link at the top, which directs the viewer to the correct section from there, rather than to a general disambiguation page. What do you think? Cheers, User:HopsonRoad 22:29, 10 March 2014 (UTC)

I've put a redirect at the top. See what you think. User:HopsonRoad 22:38, 10 March 2014 (UTC)

Looks great! The redirect doesn't seem to work when using the Wikipedia Mobile website (Firefox 27.0 on Android 4.4.2), though perhaps that should be filed as a bug report somewhere else.BananaLanguage (talk) 09:40, 11 March 2014 (UTC)

The same is true for Wikipanion on the iOS. However, iOS Safari works normally. User:HopsonRoad 16:34, 11 March 2014 (UTC)

Shouldn't there be a disambiguation page so that people looking for other uses of the word "meteor" (for example, the Gloster_Meteor) can find what they are looking for? — Preceding unsigned comment added by 94.7.91.187 (talk) 10:54, 9 August 2014 (UTC)

There already is, when you get to Meteor. It reads: "Meteor" and "Meteors" redirect here. For other uses, see Meteor (disambiguation). User:HopsonRoad 22:17, 9 August 2014 (UTC)

Meteor definition

We should clarify that meteor can (and usually does, in the mainstream media) refer to the rock itself once it's entered the atmosphere, rather than just the visual phenomenon produced by the meteor. My attempt to clarify here was reverted: [6]. Note that in addition to mainstream dictionaries, this definition also appears to be used in academic works, for example "Physics of Meteor Flight in the Atmosphere". Rolf H Nelson (talk) 02:56, 17 September 2014 (UTC)

Thank you for bringing the discussion here, Rolf. The article already attributes the visible phenomenon to the meteoroid's passage in the atmosphere. If the meteoroid fell into the atmosphere at a speed insufficient to create a visual effect, it clearly wouldn't be a meteor. Nor is the visual phenomenon possible without the passage of the rock, So, I suggest that it's the whole package and that this is already adequately clear in the current description. I felt that your proposed verbiage added words, but not clarity. I suggest that, since you feel that a preponderance of definitions are different from this, perhaps it would be useful to bring some of them here from authoritative sources and we can re-craft the description under the Meteor heading, as warranted, and reflect it in the lead section. Sincerely, User:HopsonRoad 03:17, 17 September 2014 (UTC)

I originally gave Merriam Webster dictionary entry for meteor in my edit, but The American Heritage Science Dictionary also agrees that the meteor is both the rock, and the light the rock emit. Writing for the general public, NASA's Web site states "Little chunks of rock and debris in space are called meteoroids. They become meteors -- or shooting stars -- when they fall through a planet's atmosphere; leaving a bright trail as they are heated to incandescence by the friction of the atmosphere." Therefore the current wording, 'A meteor or "shooting star" is the visible streak of light', is incomplete. The difference is that "the meteor created a large crater" is correct usage according to the dictionary definition, but incorrect according to Wikipedia's current definition, as a glow cannot create a crater but a rock can. Rolf H Nelson (talk) 02:54, 18 September 2014 (UTC)

Hi Rolf, I agree that the fragment that you cite is an incomplete definition, because you left off the rest of the sentence, which reads, "A meteor or "shooting star" is the visible streak of light from a meteoroid or micrometeoroid, heated and glowing from entering the Earth's atmosphere, as it sheds glowing material in its wake." I don't see how the complete phrase is different in meaning from NASA's. However, would it be clearer us to say, "A meteor or 'shooting star' is a meteoroid or micrometeoroid, heated and glowing from entering the Earth's atmosphere and shedding glowing material in its wake, thereby creating a visible streak of light?" Sincerely, User:HopsonRoad 21:36, 18 September 2014 (UTC)

I vote with Rolf on this one. The way it reads now, even with the comma delimited phrase, is that the "meteor" refers to "the streak of light", not to the combination of the light and the rock particles. The antecedent for "this phenomenon" is "a streak of light", and it is not clear that the word "meteor" also refers to the rock particles. I vote for using either Rolf's version (1st choice) or the expanded version in HopsonRoad's last talk comment above (2nd choice).TundraGreen (talk) 17:40, 21 September 2014 (UTC)

Thank you for your thoughts, Tundra. I'm unclear about which text you consider to be "Rolf's version,." the reverted text, or the NASA description, above. I felt that the reverted text was overly wordy for a WP entry and likewise for the NASA description, which isn't really a definition and may not fit well into the "Meteor" section under Meteoroid. The meteoroid definition quotes an authority. Perhaps we can find a more succinct quote, or distill the NASA popularized explanation. User:HopsonRoad 18:08, 21 September 2014 (UTC)

There seems to be a split between the scientific community and the popular definition. The scientific community regards a rock undergoing a transition between meteoroid and meteorite as it passes through the atmosphere as giving off light and that is the meteor, cited by the IAU Commission 22, 1961 as, " meteor: in particular, the light phenomenon which results from the entry into the Earth's atmosphere of a solid particle from space; more generally, as a noun or an adjective, any physical object or phenomenon associated with such an event" and the International Meteor Organization as, "In particular, the light phenomenon which results from the entry into the Earth's atmosphere of a solid particle from space," and by Rubin and Grossman in "Meteorite and meteoroid: New comprehensive definitions" with "Following common usage, we define meteor as the light phenomenon produced by the passage of an object through an atmosphere that heats the surrounding gas to incandescence." It's the non-technical dictionary definitions that conflate the two. I suggest that mention of both approaches can be made. Note that Wiktionary's definition uses the derivation, "(archaic) Any atmospheric phenomenon. (Thus the derivation of meteorology.) These were sometimes classified as aerial or airy meteors (winds), aqueous or watery meteors (hydrometeors: clouds, rain, snow, hail, dew, frost), luminous meteors (rainbows and aurora), and igneous or fiery meteors (lightning and shooting stars," but emphasizes the light phenomenon in the modern definition: "A fast-moving streak of light in the night sky caused by the entry of extraterrestrial matter into the earth's atmosphere: A shooting star or falling star." User:HopsonRoad 03:19, 22 September 2014 (UTC)

By the way, the original 1958 publication date of "Physics of Meteor Flight in the Atmosphere" by Ernst Julius Opik predates the IAU standardization of terminology in 1961, so I would not rely on it as a current source of terminology. User:HopsonRoad 13:24, 22 September 2014 (UTC)

Okay, according to Rubin and Grossman, in a footnote, "meteor" refers only to the light, not to the object. However, popular definitions, http://dictionary.reference.com/browse/meteor?s=t, http://www.livescience.com/27183-asteroid-meteorite-meteor-meteoroid.html, http://www.definitions.net/definition/Meteor, state that the term can refer to either the body or the light. Maybe we should include a comment that both definitions exist. That would be clearest. TundraGreen (talk) 14:58, 22 September 2014 (UTC)

Thanks for your input, TundraGreen. I don't feel that dictionary.reference.com or definitions.net meet Wikipedia:Identifying reliable sources—they have no discernible sources of authority. However, livescience.com has an editor and American Heritage Dictionary would appear to be reliable sources. So, I'm game with putting two definitions forward: one based on IAU and the other based on popular usage. User:HopsonRoad 16:03, 22 September 2014 (UTC)

I suggest that the "Proposed redefinition" covers all bases in one sentence. User:HopsonRoad 17:56, 22 September 2014 (UTC)

Proposed redefinition

A meteor or "shooting star" is the passage of a meteoroid or micrometeoroid into the Earth's atmosphere, incandescent from air friction and shedding glowing material in its wake sufficiently to create a visible streak of light. Meteors typically occur in the mesosphere at altitudes between 76 to 100 km (47 to 62 mi). The root word meteor comes from the Greek meteōros, meaning "high in the air."

Comments on proposed redefinition

Please post comments here:

• Absent further discussion, I'll be bold and incorporate the above text. User:HopsonRoad 00:51, 24 September 2014 (UTC)

Here is meteor as Wikipedia defined it on 18 March 2007. I am not sure we even need to include micrometeoroids when referring to meteor events, but I am good either way. And to be very correct we would need to include asteroids (objects larger than 1 meter across.) -- Kheider (talk) 15:28, 24 September 2014 (UTC)

Meteoric EMP

There does seem to be a verifiable electromagnetic pulse phenomenon associated with meteors, though the recently deleted material was way off beam. The term "electrophonic bolide" is also verifiable, though not directly the same effect. I'll try to put something together when I can find the time. — Cheers, Steelpillow (Talk) 10:12, 30 December 2014 (UTC)

Here is the best from among the top-listed results of a quick search:

• Charles Chandler; "Meteoric Airbursts: General Principles", QDL blog [7] (retrieved 30 December 2014)

• Colin S.L. Keay; "Progress in Explaining the Mysterious Sounds Produced by Very Large Meteor Fireballs", Journal of Scientific Exploration, Vol. 7, No. 4 (1993), pp 337-354.[8] (pdf)

• S. Close, P. Colestock, L. Cox, M. Kelley, and N. Lee; "Electromagnetic pulses generated by meteoroid impacts on spacecraft", Journal of Geophysical Research, Vol. 115, A12328 (2010), doi:10.1029/2010JA015921. [9] (pdf)

• Colin Keay's blog on geophysical electrophonics [10]

This suggests to me that although the phenomena are not widely known, the science is verifiable. But I am unsure how to integrate it into the current article structure. Three different effects are described:

1. EMP generation by the impact of a meteoroid with a spacecraft.
2. VLF radiation generated by the passage of a meteoroid (bolide) through the atmosphere, which is then converted to audible sounds - the "electrophonic bolide".
3. EMP generation by the explosive disintegration of a meteoroid in the atmosphere. (least well attested in the sources I have found to date).

What do folks think, is there anything here for the article? — Cheers, Steelpillow (Talk) 12:17, 30 December 2014 (UTC)

I think Meteoroid#Sounds of meteors pretty much covers what we have properly referenced on Very Low Frequency radio waves created by electromagnetic energy from meteors. -- Kheider (talk) 15:38, 30 December 2014 (UTC)

Adiabatic vs friction heating

Recently, a correction was made to support the notion that a meteor is made "incandescent from adiabatic heating of the air being compressed in front of the meteoroid" and the following was cited: Plait, Philip (16 October 2008). Death from the Skies!: The Science Behind the End of the World. Penguin. ISBN 1101078782. Retrieved 6 August 2015. Unfortunately, I can find no support for adiabatic heating in that source. On the contrary, Bronshten, V.A. (Dec 6, 2012). Physics of Meteoric Phenomena. Science (in English translated from Russian). Springer Science & Business Media. p. 358.{{cite book}}: CS1 maint: unrecognized language (link) argues that the Lindemann and Dobson theory (of adiabatic compression heating) is incorrect because the atmosphere is not dense enough to form a compression cap at altitudes where meteors incandesce; instead, the object is interacting with individual molecules. Either one theory should be demonstrated to be authoritative or at least the controversy should be presented. Sincerely, User:HopsonRoad 22:20, 7 August 2015 (UTC)

Go ahead HopsonRoad, make the edit that seems best to you and let's see if someone disagrees. If a controversy arises, then others will be (hopefully) start to look in more detail at the cited sources. --Cheers, Rfassbind -talk 23:06, 7 August 2015 (UTC)

I second the above, but would also like to see input from a subject matter expert (which I am not) because I think this is a rabbithole of a "simple" thing that could potentially be extremely complex. Geogene (talk) 23:56, 7 August 2015 (UTC)

Thanks for your input. The earlier version cited heating from friction, which is born out by the linked passage in the citation that I give above. The adiabatic claim appears to be discounted by other researchers in the field cited in this source. Cheers, User:HopsonRoad 00:07, 8 August 2015 (UTC)

I think "adiabatic" is the wrong word, but I'll check some other possible references and see what they say. Geogene (talk) 00:22, 8 August 2015 (UTC)

I concur—that's why I reverted it initially. User:HopsonRoad 03:02, 8 August 2015 (UTC)

Image sequence Ionization trail

Perseid meteor ionization trail visible for a minute, 3 exposures 8 seconds, and last one 30 seconds, located in ring of stars of Corona Borealis.

As per the mutually reverted edits about an image compiltation, I suggest to use only the first image, which is - in my opinion - a beautiful image. I don't see much value to show the entire sequence. If its ok with you guys, I'll will upload a cutout of the original image (and reference it to the originial on wikicommons). Would that be ok? Cheers, Rfassbind -talk 16:09, 19 August 2015 (UTC)

Ionization trail of a Perseid meteor seen against the constellation Corona Borealis with its ring of stars

It was not obvious to me that the image was of a time series—I thought that it was something taken through some cross-hairs. The subject matter in the top left panel is so small that I had to check to see whether it was dust on my computer screen. So, if this is a good representation of an ionization trail, I concur that only the first image be used. My thanks to Tomruen for contributing the image and his interest in this article. Sincerely, User:HopsonRoad 00:19, 20 August 2015 (UTC)

I just replaced the original image with said cut-out version I'm posting here as well (on the left). Apologies for not waiting any longer, but I have to close this open task of mine and move on. Hope everybody can live with this version/caption. -- Cheers, Rfassbind – talk 00:53, 24 August 2015 (UTC)

I replaced the "cut out" image with a JPG version to retain the camera timestamp. Tom Ruen (talk) 21:55, 24 August 2015 (UTC)

Shock Wave

There is a very common misconception. The sound heard minutes after a meteor flies overhead is not likely the sound of the meteor exploding. Instead, it is the sound of the shock wave (Mach cone) similar to the effect of a supersonic aircraft flying over. I think this needs to be carefully explained, and perhaps supported by a diagram. 69.50.184.51 (talk) 02:06, 2 December 2015 (UTC)

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Split proposed

As per https://en.wikipedia.org/wiki/Wikipedia:Articles_in_many_other_languages_but_not_on_English_Wikipedia 89.241.59.16 (talk) 22:35, 12 April 2016 (UTC)

Why? Geogene (talk) 22:44, 12 April 2016 (UTC)

N Oppose The link above only notes that a split is proposed, not why it should be split. I oppose the proposal that an article on meteors be split from Meteoroid because meteors are are but a very transitory phase—a flash in the sky—of the life cycle of meteoroids that enter the earth's atmosphere and come to rest as a meteorites. Any notability is merely flash and not separate from that life cycle. User:HopsonRoad 01:03, 13 April 2016 (UTC)

Action: I removed the proposed split banner in the article, because the IP editor never justified why it was necessary and only two people discussed it here, neither one seeing a justification for the proposal. User:HopsonRoad 21:47, 26 April 2016 (UTC)

Streak of light

A meteor of the Leonid meteor shower. The photograph shows the meteor, afterglow, and wake as distinct components. Is any part of this exposure due to "perception" and not physical phenomenon?

Hi User:WolfmanSF, thanks for your recent edits here. I feel that we need to better nail down what causes the streak of light of a meteor. What you appear to be supporting is that it's perceptual—having a residual image in one's vision made by the passage of a very bright object, sort of like the early days of television. However, on P 1 of Bronshten, it states, "Directly behind the meteoroid stands the wake of the meteor, whose luminosity is of the same nature as the meteor proper [my emphasis]. The meteoroid loses mass owing to vaporization, fusion, and fragmentation. The process of mass loss by a meteoroid is known as ablation." This reference clearly identifies the luminous wake of the meteor being physical and not perceptual. Otherwise, I would ask you to supply a reference that supports your statement, "rapidly moving light cannot possibly fail to create a visual streak", as applied to meteors. Bronshsten also does not support the statement, "The "streak" can result simply from the object's rapid motion, and does not require shedding of glowing material (which is an unusual phenomenon)". I look forward to your reply. However, I'll be away for about a week. Sincerely, User:HopsonRoad 18:13, 30 June 2016 (UTC)

Bronshten's comment does not indicate or require that the entire perceived visible streak resulting from a meteor's fall is simply due to an extended luminous wake that is all glowing at once. On the other hand, it is well known that in some cases of fireballs, a glowing wake can be briefly seen after the meteor itself has disappeared, but these are caused by much larger objects than the typical grain-of-sand sized meteoroid. Here is another source suggesting that ionized air molecules, rather than material shed from the meteorite, contributes to the trail:

http://www.amsmeteors.org/meteor-showers/meteor-faq/#3

It seems unavoidable to me that a light moving at 72 km/sec is going to cause a perceived streak with or without a glowing wake. I agree it would be desirable to "nail down" the origin of the streak, but finding the appropriate references may not be easy. WolfmanSF (talk) 01:19, 1 July 2016 (UTC)

Thanks for your reply, WolfmanSF. I would recommend limiting the discussion of the streak to what actually glows and how long it persists and not confuse it with the instrument that's "perceiving" it, whether that's the human eye or some form of camera with a given shutter speed. See the image, above, is any part of that due to perception? It appears to be all physical phenomenon, to me. Cheers, User:HopsonRoad 11:37, 1 July 2016 (UTC)

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True. User:HopsonRoad 21:05, 13 September 2016 (UTC)

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Gallery of meteors

The Gallery of meteors appears to contain many images that do not complement one another in contravention of MOS:IMAGERELEVANCE, which recommends, "Resist the temptation to overwhelm an article with images of marginal value simply because many images are available". If someone else doesn't commence pruning what's there, please don't be surprised if I do. If my observation is off-track, please let me know here. Sincerely, HopsonRoad (talk) 21:44, 6 March 2018 (UTC)

Why isn't Joanna Newsom in the references?

She explains all about meteorites, meteors and meteoroids in "Emily" — Preceding unsigned comment added by 158.109.31.4 (talk) 02:02, 28 July 2018 (UTC)

Hmmm, "Emily" is not a WP:Reliable source. A compilation of such items could be mentioned in a Popular culture section. HopsonRoad (talk) 14:15, 28 July 2018 (UTC)

Animation

The animation Meteoroid_meteor_meteorite.gif is easily comprehensible and suitable for the wikipedia page.

agree:

disagree:

• (this talk thread initiator) —Mykhal (talk) 08:24, 22 October 2020 (UTC)

Altitude of visibility

The following is moved from my talk page:

It is poorly understood by the general public that meteors/fireballs first become visible when they are about 100 km above sea level. The public often thinks they are visible at 10,000 km. This should be covered in the lead and not buried in the article. -- Kheider (talk) 15:02, 16 April 2021 (UTC)

HopsonRoad (talk) 16:00, 16 April 2021 (UTC)

Kheider, I concur, it was clumsy of me to have removed it, having seen that it was reflected in the text. I see that you have rectified the problem. My apologies! Cheers, HopsonRoad (talk) 16:03, 16 April 2021 (UTC)

Thank you. -- Kheider (talk) 19:02, 16 April 2021 (UTC)

significant event this weekend 25 March 2023

An asteroid big enough to wipe out a city will pass harmlessly between Earth and the moon’s orbit on the weekend of 25th March 2023. It is unusual because of both it's size and how close it will be when it passes by. Something of this size and it's proximity only happens about once a decade. It was discovered a month ago, and is known as 2023 DZ2. It will pass within 515,000km of the moon and, several hours later, fly past the Earth at about 28,000km/h. https://www.theguardian.com/science/2023/mar/24/city-killer-asteroid-to-pass-harmlessly-between-earth-and-moon Beautiful Rosie (talk) 12:22, 25 March 2023 (UTC)

2023 DZ2 is a fairly common event that last happened in 2019 with 2019 OK. And it is technically offtopic for this article. -- Kheider (talk) 12:55, 25 March 2023 (UTC)

ok sorry, I just thought it was interesting. Thanks for taking the time to let me know. I saw the article and thought that it was interesting, but was unsure. It's obviously not that big a deal! glad I just added it to the talk and not the article itself.Thank you. Beautiful Rosie (talk) 13:18, 25 March 2023 (UTC)

I agree it is interesting. I have been editing the 2023 DZ2 article and imaging 2023 DZ2. -- Kheider (talk) 13:24, 25 March 2023 (UTC)

Thanks so much for adding this link thank that's fantastic Beautiful Rosie (talk) 23:05, 25 March 2023 (UTC)