Talk:Chelyabinsk meteor

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Naming

READ=http://www.latimes.com/news/science/sciencenow/la-sci-sn-russian-tiny-asteroid-20130215,0,5424522.story?track=rss The Medvedev government is referring to it as KEF-2013 - NorthernThunder (talk) 09:35, 15 February 2013 (UTC)

 Done. BatteryIncluded (talk) 17:43, 15 February 2013 (UTC)

Since an impact crater has been confirmed it is now a meteorite and some media are now calling it as such. The article title needs to change to reflect this and we need a wikilink to meteorite. - Shiftchange (talk) 12:35, 15 February 2013 (UTC)

It seems like it also reached Kazakhstan, should it still be named RUSSIAN meteor ....? --In Allah We Trust (talk) 14:14, 15 February 2013 (UTC)

No, it shouldnt. Propose rename to 2013 Central Asian meteor event. Fig (talk) 14:37, 15 February 2013 (UTC)

I disagree. The event is now, thanks to media coverage, firmly associated with Russia in general and Chelyabinsk in particular, which is also the ground zero area of the explosion. This justifies, in my view, naming the event after Russia or Chelyabinsk. "Central Asian" simply because parts of the meteor also reached Kazakhstan would be misleading, since the public attention does not associate the event with Kazakhstan (and Chelyabinsk is arguably not in "Central Asia", but pretty much at the Western end of Asia, the Ural being traditionally seen as the border between the two continents). SchnitteUK (talk) 17:07, 15 February 2013 (UTC)

Meteoroid, meteor and meteorite are different stages. What was seen and heard was a meteor, not a meteorite. What might be found on the ground would be a meteorite, not a meteor. If you take a photo of a fetus, and then it grows into an adult human, the photo is still of a fetus, not of an adult human. Kingturtle = (talk) 14:18, 15 February 2013 (UTC)

I think it'd be cool if this article were renamed "The Chelyabinsk Event of 2013," similar to the "Tunguska Event of 1908." Just my two cents... Tomjoad187 (talk) 15:50, 15 February 2013 (UTC)

I would agree with Tomjode187 "Chelyabinsk Impact event" is specific and follows logical convention, like the article "Carancas impact event" I second a name change for this article. Richard Sidler 16:38, 15 February 2013 (UTC)

Name change good, but not just now. The current title is adequate for locating the article (which is the main purpose of a title). A more permanent name can be chosen in, let's say 3 or 4 days after media and the scientists have a chance to settle on a name. We go where the sources and the sources are still being developed.... Sailsbystars (talk) 17:13, 15 February 2013 (UTC)

I agree with Sailsbystars that a name change should hold off for a few days until media coverage has died down. With respect to the final naming, here are the titles of articles about similar events:

• Sikhote-Alin meteorite
• Tunguska event
• Peekskill meteorite
• Carancas impact event

based on these I believe this article should either be titled "Chelyabinsk meteorite", "Chelyabinsk meteor" or "Chelyabinsk impact event". Initially I searched wiki for "Chelyabinsk meteor" as that is what it is popularly refereed to in the news and I think a redirect should be created with that name to this final article. However, it does appear that experts in astronomy do in fact refer to these as Impact events although personally an "impact event" is overly vague to me without context that the impact is a object from outer space and the earth as opposed to the impact of a civil rally or whatever. Schenka (talk) 18:18, 15 February 2013 (UTC)

Re: "Chelyabinsk impact event": Actually, the meteor did not impact, but underwent an air burst. Cheers, BatteryIncluded (talk) 18:51, 15 February 2013 (UTC)

Some fragments hit the ground. --Chris.urs-o (talk) 19:49, 15 February 2013 (UTC)

Someday the Meteoritical Bulletin will be updated, Chelyabinskaya oblast' had already a hit in 1949.

"Kunashak". --Chris.urs-o (talk) 19:54, 15 February 2013 (UTC)

Just like the Tunguska event, this meteor exploded in the atmosphere, and the event resulted in injured people (so the relevance is the event taking place near a populated area not the meteor itself), therefore the Chelyabinsk event seems more appropriate. As per Wikipedia naming policy, the most popular/common/notable name shall prevail over a scientific one, specially if they come up with something fancy like the meteor Mxyzptlk-2013. But I agree with the proposal of waiting a few days.--Mariordo (talk) 00:59, 16 February 2013 (UTC)

The Tunguska event is named an event only because the cause was unknown. In this case it is known to have been a meteor, and that is the appropriate name. μηδείς (talk) 02:03, 16 February 2013 (UTC)

Probably does not have much bearing, but #Russianmeteor has been trending on Twitter. Only commenting as to what the current popular term was. I found the article by looking for "Russian Meteor".02:12, 16 February 2013 (UTC) Dlohcierekim 02:13, 16 February 2013 (UTC)

I had assumed (and hoped) this was just a "working title" until we could be certain on a more proper title. To my ear, it sounds a little odd to call the meteor "Russian", even though I understand the meaning perfectly. I think 2013 Chelyabinsk meteor sounds good. It's concise, informative and I have seen sources are using it. I have no idea what the most common usage is, but keep in mind that the current title could be gaining traction precisely because we here at Wikipedia are continuing to call it that. --RacerX¹¹ Talk to me^{Stalk me} 00:58, 17 February 2013 (UTC)

+1 for "2013 Chelyabinsk meteor". Fig (talk) 11:34, 17 February 2013 (UTC)

Meteoroid - A small particle from an asteroid or comet orbiting the Sun. Meteor - A meteoroid that is observed as it burns up in the Earth’s atmosphere – a shooting star. Meteorite - A meteoroid that survives its passage through the Earth’s atmosphere and impacts the Earth’s surface.— Preceding unsigned comment added by Kennvido (talk • contribs) 09:38, February 15, 2013‎

I think we are :). Some sources are calling it a meteorite shower, but I think most of the damage was caused by explosions in the air and not by the meteorites themselves, so I think our naming is fine. We should also wait for confirmation that actual meteorite fragments are found until we can think about renaming it. --Tobias1984 (talk) 13:15, 15 February 2013 (UTC)

Quote: "I think most of the damage was caused by explosions in the air", probably shock waves. --Chris.urs-o (talk) 13:57, 15 February 2013 (UTC)

I think the name could be either meteor/meteorite event. But I don't think the question of air burst or shock wave is settled yet. I do think it is a difference if a object flies by like an airplane or explodes like a bomb. It should probably make a difference in the distribution of the damage on a hopefully soon to come map :) BTW: nice to also see you here chris! --Tobias1984 (talk) 14:03, 15 February 2013 (UTC)

Meteoroid, meteor and meteorite are different stages. What was seen and heard was a meteor, not a meteorite. What might be found on the ground would be a meteorite, not a meteor. If you take a photo of a fetus, and then it grows into an adult human, the photo is still of a fetus, not of an adult human. Kingturtle = (talk) 14:18, 15 February 2013 (UTC)

Thx Tobias1984. Quote: "Although there is no strict definition of the term, this object seems best designated a bolide because it was very bright, exploded, and was audible." Don't like it. Stony meteorites explode, it'd be normal. I hope somebody finds a fragment. --Chris.urs-o (talk) 14:48, 15 February 2013 (UTC)

It was definitely not a comet as someone mentioned. Comets are from the Oort cloud and are made of mainly different types of ice. A meteor comes from the asteroid belt typically. If the meteor hits the ground it is called a meteorite. There can be many different types of meteorites - stony, iron, chondrites, etc. Happy to explain differences. Volcanoman7 (talk) 05:55, 16 February 2013 (UTC)

It was a meteor. The fragments that reached the surface are called meteorites. The term meteoroid does not apply here, at it is defined as a small space object no larger than 1m in diameter. Cheers, BatteryIncluded (talk) 17:59, 17 February 2013 (UTC)

This name, "2013 Russian meteor event", has got to be the worst ever at Wikipedia. First off, "event" serves no purpose and tells us nothing. We might as well have Occurrence of the 2013 Russian meteor event happening. Second, the year is only necessary when there are multiple notable events. But other strikes like the Tunguska event (called an event because its nature is unclear) and the Sikhote-Alin meteorite are specified by their specific location, not Russia or The Soviet Union and the year in which they occurred. The article should be moved to Chelyabinsk meteor as reflected by The Independent, The Guardian, Huffington Post, Slate, CNN, La Prensa, Times of India, BBC, etc. μηδείς (talk) 21:09, 15 February 2013 (UTC)

have you seen the discussion above at Talk:2013_Russian_meteor_event#Are_we_using_the_right_term_for_this_object.3F? It isn't the first Chelyabinsk event, so I'm not sure where consensus will go. I think we are waiting for the media to settle on one name or another. Dlohcierekim 21:16, 15 February 2013 (UTC)

The article was created 14 hours ago...before any names were given to the meteor or the event. Article names can change over time as a better name is determined. In the short term, don't worry about it, and instead worry about expanding the contents. • Sbmeirow • Talk • 21:17, 15 February 2013 (UTC)

i should have referenced Talk:2013_Russian_meteor_event#Naming Dlohcierekim 21:19, 15 February 2013 (UTC)

• 2013 Russian meteor strike is my suggestion. Abductive (reasoning) 10:43, 16 February 2013 (UTC)

Most Wikipedias around the world are calling it Chelyabinsk event. Should we? --Camilo Sánchez Talk to me 17:54, 17 February 2013 (UTC)

Direction of the object

Could we sort out which direction the object was moving for the section "Unrelated Asteroid approach?" I pulled a statement from NASA saying that it was north to south while another source stated east to west. The article saying east to west is in Russian, so I'm unable to decipher it.Cheerioswithmilk (talk) 16:32, 15 February 2013 (UTC)

This would be going into original research, but I believe NASA is wrong. The path is more east to west. I have collected a playlist of footage on YouTube. It is also worth looking at the smoke trail videos, as they will show the direction of the sun. And yes, the sun does not rise from the east in Siberia in the winter. -- Petri Krohn (talk) 16:47, 15 February 2013 (UTC)

The exact direction can be inferred from this video from a webcam facing south on Revolution Square in central Chelyabinsk. The shadows of the street lamps are seen traveling almost exactly west to east on Lenin Prospect, which would indicate an east-west path for the meteor. -- Petri Krohn (talk) 17:01, 15 February 2013 (UTC)

Since this is a bit disputed, I've removed the north south direction for now.Cheerioswithmilk (talk) 17:11, 15 February 2013 (UTC)

Because both events are over now, I removed "estimated" and "will pass". The Guardian quotes NASA (north to south). Eventually a better source might be available. -SusanLesch (talk) 00:32, 16 February 2013 (UTC)

I changed to north to south, because Chelyabinsk is north of Chebarkul, because of (Quinn, Ben and agencies (February 15, 2013). "Asteroid misses Earth by 17,000 miles after meteor strikes Russia". The Guardian (Guardian News and Media). http://www.guardian.co.uk/science/2013/feb/15/asteroid-misses-earth-meteor-strike. Retrieved February 15, 2013.) and because of this picture ([1]). Scientific American, Meteor researcher Margaret Campbell-Brown [2]:

Energy of the explosion was about 300 kilotons of TNT equivalent

About 15 meters in size

Moving at about 18 kilometers per second, which is about 65,000 kilometers per hour

A mass of probably about 7,000 metric tons

Fireball begins at c. 50 km altitude

Main energy release at 15 to 20 kilometers altitude

--Chris.urs-o (talk) 13:22, 16 February 2013 (UTC)

NASA update (February 15, 2013 7pm PST) [3]:

Disintegrated in the skies over Chelyabinsk, Russia, at 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15)

Estimated size of the object, prior to entering Earth's atmosphere, 55 feet (17 meters)

Estimated mass 10,000 tons

Estimate for energy released during the event 500 kilotons

The event, from atmospheric entry to the meteor's airborne disintegration took 32.5 seconds

(This gives a density of c. 3.9, that is greater than c. 2.6 of a stony meteorite, so stony-iron meteorite (mesosiderite or pallasite), probably)

--Chris.urs-o (talk) 13:34, 16 February 2013 (UTC)

Monte Morin (15 February 2013). "Russian 'meteor' was actually a tiny asteroid, NASA says". Los Angeles Times. Event occurs at 6:30 p.m. Retrieved 17 February 2013.

“Tiny asteroid”, 45 feet across (13.7 m), about 10,000 tons and traveled about 40,000 mph (64,400 km/h).

--Chris.urs-o (talk) 12:50, 17 February 2013 (UTC)

Petri Krohn's conclusion above that the meteor followed a more east to west direction trajectory, instead of the north to south direction mentioned by other sources, is correct. As he points out the shadows of the street light poles move west to east on the roadway below in this south looking view looking, which implies a definite east to west motion component of the light source. Moreover, the shadows of the light pole tips travel almost exactly parallel to the east west running lanes on the road below (along a line from about170 degrees to about 80 degrees). Thus the line traced out by the shadow tips on the road surface and the tip of one of the light pole tops in the center of the picture define a plane in which the light source had to have been moving. Given the proportions in the video, such as car sizes, light poles are likely about 10 m tall. The shortest pole shadow lengths appear to be about the height of the pole. This entails that the aforementioned plane would have an about 45 degree inclination toward the south, with the pole tip shadow line on the pavement forming the intersection between that plane and the plane defined by the pavement. The initial pole shadows pointed toward an about 300 degree heading (light source in the east southeast area and traveled over about the next 5 second time interval via the 360 reps. 0 degree heading to an about 40 degree heading. The brightest flash was recorded when the shadows pointed toward an about 340 degree heading. If the meteor came in on a trajectory tangential to the earths surface, i.e. on a grazing trajectory, it would have to have been traveling pretty much exactly from east to west. However, if the meteor came in on a path inclined to the local Chelyabinsk horizon plane, then it must have come in from an E to SE direction, traveling toward W to NW. The steeper the more from a southerly direction.

The meteor "flashed" brightly when it was SSE of Chelyabinsk at an about 160 degree heading (to go with the above mentioned about 340 degree heading of the light pole shadow at the time of the "flash"). Because the meteor presumably "burst" about 20 to 30 km above ground, and given the above mentioned putative motion planes inclination, that "flash" had to have occurred above an area located about 20 to 30 km SSE of Chelyabinsk. This puts the "flash" location roughly SSE and halfway between Chelyabinsk and Yemanzhelinsk and pretty much exactly due east from Chebarkul and its adjacent lake, where some of the fragments supposedly impacted on earth. Also, over the roughly 5 Seconds long period of the "light show" the shadow of the pole tips traveled about 3 pole heights along the pavement from west to east, or about 30 m given the above assumptions. This makes for an about 6 m/s west to east motion for the pole tips shadow. Given the 10 m light pole height, the 45 degree inclination of the putative plane of motion of the meteor, and the roughly 20 to 30 km SSE location of the "flash" this results in an about 15 km/s east west component for the meteors velocity. This leaves very little for a south to north velocity component, considering the 15 to 18 km/s total velocity estimated by others for this meteor. Looks like a grazing trajectory with an approach from E to ESE toward W to WNW is a pretty good guess after all. A "south to north" trajectory is not likely a good guess, and a "north to south" trajectory is impossible given the evidence.Jbwischki (talk) 23:23, 16 February 2013 (UTC),

The best analysis of the path of the meteor is presented in these two pages:

• Reconstructing the Chelyabinsk meteor’s path, with Google Earth, YouTube and high-school math
• Chelyabinsk meteorite, 2013 February 15th on Google Maps

The dierection of the trajectory is from east by south, not north to south as previously claimed. The explosion happened at a height of 27 km above the town of Korkino, about 40km south of central Chelyabinsk. -- Petri Krohn (talk) 00:29, 18 February 2013 (UTC)

2.7 magnitude quake recorded in Ural Mountains Region, Russia

I found an article in The Christian Sciences Monitor which refers to a 2.7 magnitude quake recorded by the United States Geological Survey. The quake was centered around the Ural Mountains Region in Russia and occurred on Friday, February 15, 2013 at 03:22:00 UTC (approximately two minutes after the meteor entered the atmosphere). It is almost certain that this quake was a direct result of the shock wave created as the meteor exploded into a fireball. Interesting to note is that the earthquake was not considered a 'normal' quake by geological standards. Many Russian eyewitnesses reported experiencing simultaneous thundering in the sky as the ground shook beneath their feet. I also found the USGS page with an official record of the quake yet it is in the older page format and a newer page needs to be found. The USGS does not cite the magnitude of the quake, but it is at the agency's 2.5 magnitude threshold so they are still deciding upon the correct magnitude. Perhaps a better USGS source needs to be found to confirm the report.

"Russia meteor blast produced 2.7 magnitude earthquake equivalent" "Magnitude ? (uncertain or not yet determined) - URAL MOUNTAINS REGION, RUSSIA") 119.12.246.165 (talk) 07:29, 16 February 2013 (UTC)

a 2.7 magnitude is an extremely small earthquake and wold hardly be felt. The fact that it hit water would also make me believe that the earthquake may not be related to the impact. THe key way to test this is to see if the epicenter was near the city where the meteorite hit. Volcanoman7 (talk) 07:04, 16 February 2013 (UTC)

It is reported that the quake did not have an epicenter. Paul Caruso, a geophysicist at the USGS National Earthquake Information Center in Denver, Colorado is quoted as saying ""When you have an explosion in the air, it shakes the ground, and we see it on the seismographs... It's not an earthquake, and it looks very different from the usual earthquake seismogram". The Christian Sciences Monitor points out that it was a "magnitude earthquake-equivalent", not a natural earthquake. As Christian Sciences Monitor is reporting, the quake was unusual in that it did not emit the same signal as a natural earthquake and the USGS reports that it occurred approximately the same time the shock wave hit the ground. People reported feeling the earth trembling and quaking underneath their feet at exactly the same time as when the shock wave hit, which was approximately two and a half minutes after the actual explosion. So all those factors line up apart from the time of the air burst, which is said to have occurred exactly at 03:20:26 UTC, not at "approximately... 03:13 UTC" as according to the article. 119.12.246.165 (talk) 07:31, 16 February 2013 (UTC)

The USGS originally reported the earthquake happening at 03:22:00 UTC. How they changed their report to state 03:20:26 – based on what? Reading Wikipedia? I am still trying to find out the delay from the explosion to the shock wave reaching the ground. The earthquake data would help, if the USGS would stick to their own measured data, and not publish what they happen to read on the internet. -- Petri Krohn (talk) 03:48, 17 February 2013 (UTC)

Do you have a source to show that the USGS obtained their data from the internet or are you basing this on the time parallel between the reported explosion and earthquake? This factor needs to be resolved as it does not answer the 90-150 second delay it took for the shock wave to make contact with the ground. And can you provide a source to the original USGS report stating an earlier time frame for the quake? It appears these are discrepancies that need to be sorted out.1.178.161.116 (talk) 08:54, 17 February 2013 (UTC)

I am still trying to find the USGS seimographic data for event USC000F7RZ. I can find these two web pages. Both of them now state a time of 03:20:26 UTC, but Google and several mirrors on the web say the pages originally carried a time of 03:22:00 UTC. Given the time the shock wave needed to reach the Earth, it is likely that 03:22:00 UTC could be the correct time for the seismic event. It is thus feasible, that the USGS concluded this time based on their seismic data. Apart from the web traces I have this low resolution screenshot of seismic waves from some USGS related software, with the timestamp of 03:22:00 UTC.

I think it is a bad idea for USGS to tweak their data based on what NASA or the press tells them. It undermines the value of their own observations.

As for the 03:20:26 UTC time for the explosion, I think this may be some value just floating around in the internet echo chamber. Local CCTV records say the flash happened at 03:20:31.5 UTC. -- Petri Krohn (talk) 15:49, 17 February 2013 (UTC)

03:20:26 UTC is the time of the air burst as quoted by NASA during an official press conference, according to various scientific and astronomical sources. More research needs to be done to clarify this statement and the actual instrumental measurements (or official references to them) need to be obtained for confirmation. 1.178.33.170 (talk) 23:28, 17 February 2013 (UTC)

American weapon

The article had a claim by Vladimir Zhirinovsky that it is not meteor event, but American weapon testing. Since is a fringe view, I removed it from the mainstream reaction section and added in a section titled American weapon conspiracy theory. But my edit was removed by Bongwarrior (talk · contribs) with an edit summary, removed per WP:UNDUE - "Generally, the views of tiny minorities should not be included at all". After Bongwarrior removed Zhirinovsky claim, Medeis (talk · contribs) re-added it with an edit summary notable reaction. Now you guys decide whether Zhirinovsky view should stay or not. --PlanetEditor (talk) 07:35, 16 February 2013 (UTC)

PS My view is that this claim can stay only under a separate subsection titled "Conspiracy theory" (as I did), not among the mainstream reactions. --PlanetEditor (talk) 07:36, 16 February 2013 (UTC)

The person is notable, but his viewpoint is not. It runs afoul of WP:UNDUE by a wide margin. I'm sure that eventually there will be a 2013 Russian meteor conspiracy theories article. His opinion belongs there, not here. --Bongwarrior (talk) 07:44, 16 February 2013 (UTC)

My view is that for now WP:UNDUE precludes a mention of it. If it becomes a significant aspect of coverage of the event, things may change. But for now, let's exclude it. Evanh2008 ^{(talk|contribs)} 09:46, 16 February 2013 (UTC)

The whole idea is just idiotic, has been disproven by scientists around the world, and has no place in the article. HammerFilmFan (talk) 13:51, 16 February 2013 (UTC)

Wiki should be about facts, and quotes about facts are to me a form of heresay. In short, unless Zhirinovsky can be quoted as having said something factual about the event, his "theories" should be left out of this and any other articles on Wiki except, perhaps, in an article about Zhironovsky himself. Otherwise, Wiki turns into a forum for kooky demagogues of all sorts. Popularity does not a scientist make, nor should a popular idea be given the same weight as a rigorously tested and peer-reviewed one. — Preceding unsigned comment added by 70.88.158.233 (talk) 22:15, 16 February 2013 (UTC)

Meteorite fragments have already been recovered. There is no controversy worth including. Really. Cheers, BatteryIncluded (talk) 14:05, 16 February 2013 (UTC)

• Well of course the view is idiotic, but we're not presenting it as an actual theory of what happened, we are presenting it as the notable reaction of a notable figure attributed to him (WP:ATTRIBUTE) and presented in the reactions section, which is exactly what it is. Zhirinovsky has been an important figurein Russian politics since the fall of the Soviet Union, a party founder, presidential candidate, and currently second highest ranking member of their congress, and his comment has been highly covered by the press. The comment belongs in a comprehensive article--we just treat it properly as an attributed and widely criticized claim attributed to him and no presented by us in the scientific section of the article. μηδείς (talk) 14:21, 16 February 2013 (UTC)

• Zhirinovsky's claim is obviously greatly mistaken and WP:FRINGE. But I'd also point out that WP:PSCI states that "pseudoscience may in some cases be significant to an article" so long as it is not given undue weight. In this instance, (a) Zhirinovsky is a notable Russian politician, and (b) his remarks have been widely reported in the media. For example, I typed "Zhirinovsky" into Google News and at the time of this writing, Google returned a large number of stories reporting his opinion on the meteor in such respected publications as the Globe and Mail and the International Business Times just to name a couple examples out of many. I would regard that evidence of notability as indicative that WP:PSCI's "may in some cases be significant" could apply here. I noticed yesterday evening that the article at the time contained a one sentence statement of Zhirinovsky's claim followed by another sentence explaining why his claim was in error (link to old version). I do not regard that as WP:UNDUE in light of the much greater attention the article devotes to the mainstream scientific narrative of this incident. --Mike Agricola (talk) 15:56, 16 February 2013 (UTC)

• Currently, Russia blames the West for all bad. This should be somewhere else, but not here. --Chris.urs-o (talk) 16:00, 16 February 2013 (UTC)

• Zhrinovsky is an important figure in Russian politics whose views are taken seriously by millions of people (so hardly "fringe"), his view is being reported by multiple reliable sources[4] and to include one line about it is hardly WP:UNDUE. To delete it is entirely POV (I note the main deleter is a user called BatteriesIncluded whose relevant edit summaries are about Elvis and farting ("Or maybey Elvis farted"), rather than whether Zhirinovsky is a national figure and whether the story is being widely reported in reliable sources. By the same token, he might as well mention the King and farting when Obama makes a religious comment, although I think the edit wouldn't last a minute and the summary would be seen as disrespectful). Of course Zhiro is batty, but that is quite irrelevant, given the first three points I have made. It should be included and I have re-instated it where I put it in the first place: Reactions. Ericoides (talk) 09:04, 17 February 2013 (UTC)

Comment A priest is now calling it wrath of God [5][6]. So I will support creation of an article titled 2013 Russian meteor alternative theories in the same fashion as RMS Titanic alternative theories, Korean Air Lines Flight 007 alternative theories. All the nonsense will belong there. --PlanetEditor (talk) 16:28, 16 February 2013 (UTC)

From my research I can see three types of fringe theories are emerging: 1. it is an American weapon test, 2. it is wrath of God, 3. alien and UFO activity. --PlanetEditor (talk) 16:37, 16 February 2013 (UTC)

Zhirinovsky's is not a fringe report, he always makes such silly arguments. It is not a theory at all, but a simple cliche. How is wrath of God a fringe theory? Only because you are an atheist does not make it a fringe theory. The last three things are invented by yourself or other people, so rather belongs to a fiction book. Regards.--Tomcat (7) 18:09, 16 February 2013 (UTC)

Only because you are an atheist does not make it a fringe theory.

Right. A solid religious alternative is that the Flying Spaghetti Monster lost a meat ball. BatteryIncluded (talk) 05:59, 17 February 2013 (UTC)

Well said :) --PlanetEditor (talk) 09:25, 17 February 2013 (UTC)

I think you are missing the point. We all agree that Zh is bonkers. You don't need a PhD to see that. What is being asserted is that multiple reliable sources have reported a remark made by an important political figure in Russia; all we are doing is reporting these reports; we are a tertiary source, after all. Ericoides (talk) 10:17, 17 February 2013 (UTC)

• I think we should give all these nonsense theories a few weeks to play out. Right now immediately after the event all sorts of people are claiming everything possible. If the conspiracy theories play out and they persist to receive notable coverage, they they might be worthy to include. Schenka (talk) 18:40, 16 February 2013 (UTC)

• Seconded. --PlanetEditor (talk) 18:50, 16 February 2013 (UTC)

• Zhirinovsky's remark is a political cliche, a priest's expression is a religious belief and the alien thing is bogus. None of them are scientifical or pseudoscientifical theories. Regards.--Tomcat (7) 19:02, 16 February 2013 (UTC)

The only notable aspect of this weapon claim is that it is idiotic and irrelevant for an encyclopedia. CHeers, BatteryIncluded (talk) 18:47, 17 February 2013 (UTC)

• So, do we have consensus to omit this "theory"? Medeis apparently doesn't believe so, since he has just re-added it for (I think) a second time. --Bongwarrior (talk) 04:16, 18 February 2013 (UTC)

TNT equivalent

Wikipedia is not a forum

Could somebody tell me. Why here on Wikipedia, which is intended for more or less intelligent people, we repeat the BS "the press", which is intended for complete idiots, is repeating in order just to say something, because "being quiet means losing the audience"? NASA said that the energy release was about 500kt. WHAT does it have to do with Hiroshima or Nagasaki? It wasn't momentary release that you get from an atomic bomb. It's the whole amount of energy this thing spent while slowing down in the atmosphere. Actually, if NASA really said that, they all should be fired, because what they were talking about is kinetic energy, while kilotons are used to measure the potential energy. Was I the only one paying attention at the Physics class? In just one year EACH of us releases more energy than the Hiroshima bomb. Cmon, people, wake up this wonderful Saturday morning and get your common sense out of the glass. BadaBoom (talk) 15:03, 16 February 2013 (UTC) Well at 18 kilometers per second things went pretty fast, and after the air burst a lot of the kinetic energy was lost ;) --Chris.urs-o (talk) 15:09, 16 February 2013 (UTC) And kinetic energy is measured in..? Want to buy a vowel? :-) The second question is: if an object moves at 18 kilometers per second, CAN it fall on the surface of the Earth OR will it be moving faster than the "third space speed", allowing it to overcome the Earth gravity? Conclusion. Stop listening to the television. They are all ignorant morons. Did I spell that right? BadaBoom (talk) 16:54, 16 February 2013 (UTC) This is not a discussion forum, nor do we allow original research. But if you don't know the answer to the second question, why should I consider your answer to the first? Instead we rely on actual experts like NASA. Rmhermen (talk) 17:04, 16 February 2013 (UTC) I'm sorry, WE? Who's we? Have you ever heard of rhetorical questions? Or the sense of humor? Is this too many questions? BadaBoom (talk) 17:33, 16 February 2013 (UTC) I just want to point out that Wikipedia is an interactive, collaborative effort therefore the term "we" is highly appropriate in this case. There can be dozens of editors and contributors at any one time in any given article. I hope that clears that up :-) 1.178.161.116 (talk) 01:34, 17 February 2013 (UTC) We means Wikipedia and we have a large number of agreed rules including our No original research policy. Rmhermen (talk) 18:34, 17 February 2013 (UTC)

Active versus passive smaller asteroid search

Nature magazine said this: "Klinkrad says it would have been hard to give warning of the blast. In addition to being relatively small in size, the rocky meteoroid was probably dark in colour, making it even harder to spot against the backdrop of space. "We just have to live with it," he says."

Are there any sources that cite *active* search methods like emitting radio signals into the space and catching reflections of the incoming objects, instead of passive one like watching in telescopes? 93.80.36.132 (talk) 19:36, 16 February 2013 (UTC)

Radar astronomy requires very specific targeting to be useful. Optical telescopes have a wide-field of view. Radar telescope would be worthless for searching for unknown objects and would have a very limited range. Infrared telescopes in space would be the best solution. -- Kheider (talk) 19:57, 16 February 2013 (UTC)

The U.S. used an infrared observing satellite to look for dark objects, see Wide-field Infrared Survey Explorer. Rmhermen (talk) 21:54, 16 February 2013 (UTC)

Subject for Wikinews

It should be easily possible to create out of such an article like this an entry to Wikinews, which is often lagging far behind topical themes. --Sae1962 (talk) 20:52, 16 February 2013 (UTC)

• In that case, I would encourage you to WP:BEBOLD and contribute to Wikinews accordingly. --Mike Agricola (talk) 21:19, 16 February 2013 (UTC)

Short tons ?

Do we have a source to say that the NASA articles is using short tons as a unit. The way it is written, I see only "Tons". Is it customary for NASA to use short tons ? 83.163.5.82 (talk) 07:22, 17 February 2013 (UTC)

This is just one of many reasons why this article (and all of Wikipedia) shouldn't use non-SI units. But there are always a few SI-illiterate editors that keep adding in conversions and make articles utterly unreadable. --Tobias1984 (talk) 09:12, 17 February 2013 (UTC)

I concur. It would be nice to see a more prominent use of SI/Metric units to more accurately define quantities of anything, though there will always be a confusion caused by countries that maintain use of older or outdated measurement systems. Americans use the imperial 'ton' as opposed to the metric 'tonne', but often the term 'ton' is used as a noun to mean a large extent, amount, or number. More often than not NASA will use the imperial short 'ton' (2000 pounds) rather than the metric 'tonne' (2240 pounds). 1.178.161.116 (talk) 09:22, 17 February 2013 (UTC)

NASA made a rough estimate of "10,000 tons". With this degree of precision (or lack of), it doesn't matter which type of ton it is. The article should just quote NASA directly and say "10,000 tons". Bubba73 ^{You talkin' to me?} 15:21, 17 February 2013 (UTC)

Who said it was an asteroid? - ESA and NASA

On 15 February 2013, a small asteroid entered Earth's atmosphere over Russia at approximately 09:20 Yekaterinburg time (03:20 UTC), becoming a fireball.

In actual fact, NASA says nothing about it having been an asteroid. They just call it an 'object'. Could have been a comet. Or God knows what else. I believe the correct term should be Small Solar System body. 77.245.119.254 (talk) 10:47, 17 February 2013 (UTC)

This reference may help... Live Science 1.178.161.116 (talk) 11:08, 17 February 2013 (UTC)

Unfortunately, no, it doesn't. NASA is the most authoritative source we can find, and they call it an 'object': [7]. 77.245.119.254 (talk) 11:22, 17 February 2013 (UTC)

I just checked the NASA article you refer to and notice that the term 'meteor' is used 13 times whereas the term 'object' is used only 6 times. I think that provides sufficient evidence from NASA to suggest they overwhelmingly prefer to call the object a 'meteor' rather than just an 'object'. 1.178.161.116 (talk) 11:44, 17 February 2013 (UTC)

Well, of course it was a meteor. The problem is that nowhere does NASA say it was an asteroid. 77.245.119.254 (talk) 11:51, 17 February 2013 (UTC)

That is true. The reference I provided explains that there is no agreed term within the scientific community as to what a meteoroid actually is. Technically a meteoroid is a 'small asteroid' yet is smaller than an asteroid, so the application of the term 'small asteroid' is correct, but at the same time it can be misleading. The correct usage of the term would then be 'meteoroid' because a meteor did not come into existence until the meteoroid entered the atmosphere. 1.178.161.116 (talk) 12:08, 17 February 2013 (UTC)

That is pure speculation. The authoritative sources do not use term 'asteroid'. Hence, we shouldn't be using it either. 77.245.119.254 (talk) 12:14, 17 February 2013 (UTC)

Russian 'meteor' was actually a tiny asteroid, NASA says : "At a news conference Friday, NASA scientists said the object that exploded over Russia was a “tiny asteroid” that measured roughly 45 feet across, weighed about 10,000 tons and traveled about 40,000 mph." 83.163.5.82 (talk) 12:29, 17 February 2013 (UTC)

I have already changed 'small asteroid' to 'object'. Seems to be more neutral, for now. 77.245.119.254 (talk) 12:32, 17 February 2013 (UTC)

European Space Agency also calls it asteroid. ESA calls it asteroid, NASA calls it asteroid, we have two independent international space agencies which both call it asteroid. 83.163.5.82 (talk) 12:40, 17 February 2013 (UTC)

http://neo.jpl.nasa.gov/faq/ — Preceding unsigned comment added by 1.178.161.116 (talk) 12:53, 17 February 2013 (UTC)

Well, feel free to change it back to asteroid, if you think it's appropriate. Personally, I have no idea how they would distinguish an asteroid from a comet post factum. But that's only me.77.245.119.254 (talk) 12:56, 17 February 2013 (UTC)

It might be better to form a compromise and call it a 'celestial object', 'near earth object' or something along those lines. Any 'small asteroid' (aka 'meteoroid') becomes a meteor when it enters the atmosphere so 'asteroid', 'tiny asteroid', 'small asteroid' and 'meteoroid' are all terms used to essentially describe the same 'thing'. 1.178.161.116 (talk) 13:11, 17 February 2013 (UTC)

94% of NEOs are asteroids. The Russian impactor was estimated to have aphelion (furthest distance from the Sun) @ 2.5AU (in the asteroid belt). -- Kheider (talk) 13:26, 17 February 2013 (UTC)

Yes, it was an asteroid. We know that because it's orbit was reconstructed, it had a 2 year orbit that brought it out to the asteroid belt (Orbit of the Russian Meteor [8]). Also, a meteoroid is <1 metre to 2 mm and an asteroid is >1 metre. The upper size limit of an asteroid is ill-defined (Meteorite and meteoroid: New comprehensive definitions [9]) --Diamonddavej (talk) 15:15, 17 February 2013 (UTC)

To be honest, this 'reconstruction' looks very dubious to me.77.245.119.254 (talk) 16:09, 17 February 2013 (UTC)

Thank you for the links: Orbit of the Russian Meteor / How Do We Know the Russian Meteor and 2012 DA14 Aren't Related? -- Kheider (talk) 15:33, 17 February 2013 (UTC)

A comet would not have produced such air burst as they are made mostly of water and dust. Incontrast, asteroids contain large amounts of metals, including iron, wich absorbs a lot of heat and is more difficult to vaporize upon entry. Naming this asteroid (meteorite) as an "object" is not useful and lends itself to conspiracy theories. We we know the "object" was a meteorite, so call it what it is. CHeers, BatteryIncluded (talk) 17:48, 17 February 2013 (UTC)

That's inaccurate. A cometary body would hit the atmosphere with a tremendous force and the energy released would be quite spectacular (this was an asteroid, that's known for several reasons, just wanted to correct the above misconception.) HammerFilmFan (talk) 20:52, 17 February 2013 (UTC)

Conspiracy theories - well deserved

Sorry, but so many things are odd about this story that I can actually understand the conspiracy theorists this time.

I mean, seriously... it's a COINCIDENCE that the biggest meteor in 100 years reaches the Earth hours before the OTHER biggest meteor in 100 years?

And then, I've just read that authorities have "given up" looking for fragments of the meteor, and that the 8 meter hole in that lake's ice sheet was "not caused" by the meteor. So by WHAT do exactly round 8 meter holes in lake ice sheets get caused?

All very strange...

And am I the only one who finds it even stranger that NASA estimated a 500 kiloton BLAST from a 10-kiloton (10,000-ton) mass? This does not sound like (a) vaporization due to heat, or (b) a chemical explosion of a 10-kiloton mass of TNT. That seems to leave a nuclear mechanism... but many years of speculation about the Tunguska event have not come up with a plausible mechanism for a nuclear detonation in an incoming rock.

The meteor that entered the atmosphere over the Ural Mountains had a trajectory that was perpendicular to the path of asteroid 2012 DA14. This means they did not approach the earth on the same trajectory as each other. The hole is 6 meters, not 8 meters and the lake is not the only probable location of meteor fragments. The meteor and the asteroid arrived approximately 15 hours apart. And yes, coincidences do happen. These are not just isolated incidents. Meteors enter the Earth's atmosphere on a weekly basis and represent nothing unusual. Asteroids also pass the Earth on a regular basis and occasionally will coincidentally align along similar trajectories or timed Earth approaches. It so happens that the Russian meteor entered the atmosphere at such an angle and velocity that it managed to cause as much of a spectacle and damage as it did.1.178.161.116 (talk) 11:08, 17 February 2013 (UTC)

"Objects the size of the Russian meteor enter the Earth's atmosphere on a weekly basis" No, luckily not, objects of 10000 tons don't enter the atmosphere on a weekly basis. 83.163.5.82 (talk) 12:25, 17 February 2013 (UTC)

You are correct. I withdraw that comment. It was supposed to read "Objects the size of the Russian meteor do not enter the Earth's atmosphere on a weekly basis. Smaller meteors represent nothing unusual." My bad. I have simplified it anyway. In fact, now that I think about it... the Wikipedia page Impact Event provides a handy reference chart as to the frequency of stony asteroid impacts that generate an airburst. If we spent more time tracking meteoroids then we'd have a more accurate number of actual approaches and near misses. 1.178.161.116 (talk) 13:04, 17 February 2013 (UTC)

Sorry to have spammed the Talk page with this. But nowadays, where every politician lies all day and secret service agents are practically proven to assassinate "impractical" scientists in clichee motorbike attacks, just like in James Bond movies, it's really difficult at times not to believe in conspiracies. I heard about the different trajectories too, but then again, there was lots of contradictory information even about those. The probability for TWO "100-year meteors" passing by Earth so closely both in space and time is probably extremely low, so I was really baffled and though that the Russian meteor MUST be a fragment of the bigger one. Maybe it is and its trajectory was altered by gravity? No idea... anyway...

• Objects frequently come within 5 LD (Lunar Distances) and we will not detect most of the objects less than ~20 meters in diameter until they are ~2 days from impact/closest approach. Should the object be too close to the Sun in the sky, or if the surveys are looking in a different region of the sky, the ~20 meter objects can easily be missed altogether. 2005 YU55 (360 meters in diameter) passed @ 0.85 LD on 8 November 2011 and nothing happened. People just want to see a pattern in everything. -- Kheider (talk) 13:50, 17 February 2013 (UTC)
• Firstly, meteors appear in Earth's atmosphere, not in space and secondly, we have clear satellite images of the meteor signature over the Ural Mountains and clear long exposure images of the trajectory of DA14. There can be no contradiction as to the trajectories of either object as they are calculated to have been traveling in opposite directions. More accurately they were traveling in perpendicular directions. The meteor traveled east to west in a south to south-westerly direction and the asteroid passed the Earth from south to north in a north to north westerly direction. 1.178.161.116 (talk) 14:25, 17 February 2013 (UTC)
• Clearwater Lakes in Canada are a rare example of a double asteroid impact. The craters were formed when twin asteroids, gravitationally bound, impacted the Earth. DA14 was not associated with the Russian asteroid as it, as they weren't orbiting each other. --Diamonddavej (talk) 15:28, 17 February 2013 (UTC)
• The escape velocity from 2012 DA14 (based on a rocky asteroid with a radius of 25 meters) is only 0.025 meters (0.98 in) per second. As a rule of thumb for rocky asteroids, the radius (in km) roughly equals escape velocity (in meters per second). Since binary NEOs have a pathetically small hill sphere, none of the satellites orbit more than a few km from the primary body. Anything pulling on a satellite of DA14 would pull on DA14 equally. -- Kheider (talk) 16:13, 17 February 2013 (UTC)

As the question why two 100-year meteors happen on the same day is only being asked because a 100-year meteor had happened, the chance of two is only that of ONE 100-year meteor. And if Russia happen later, up to 16 hours after, it would've been just as remarkable, 36,525/(32/24) equals a 1 in 27,393.75 chance, which is, needless to say, remarkable. Sagittarian Milky Way (talk) 17:52, 17 February 2013 (UTC)

The evidence collected from space and on site takes care of the conspiracy theories. I have not seen any worth mentioning in this article. Regarding the persistent introduction of the "American weapon" accusation, it is frankly, a moronic statement, non-notable (WP:Notability) and without importance. Cheers, BatteryIncluded (talk) 17:53, 17 February 2013 (UTC)

L1 Lagrangian point shepard = related ... this discussion got archived by someone trying to silence it - is this now what wiki is? - you dont want original research but you want to just accept all the next day pseudoscience that is being added to the wiki article - is wiki an encyclopedia or just a garage band fad?--68.231.15.56 (talk) 20:05, 17 February 2013 (UTC)

oh and again for the record, the supposed opposing directions of both objects are irrelevant - that pseudoscience is not what wiki is--68.231.15.56 (talk) 20:08, 17 February 2013 (UTC)

Is north-south / north-south correct?

Regarding section Coincidental asteroid approach:

"The Chelyabinsk meteor was moving from north to south, whereas the trajectory of the asteroid was from south to north."

Is that really true?

The inclination of the orbit of the asteriod, 2012_DA14, is only 11.60° (also illustrated in ), so I would expect it to move from west to east (if the asteroid is overtaking the Earth), and not from south to north. The Russian meteor moved from east to west according to the figure in section Object and entry, "The meteor's path, with Chelyabinsk marked."

--Mortense (talk) 16:53, 17 February 2013 (UTC)

The east/west motion almost exactly cancels out Earth's, leaving only the slight northward incline to be felt. Also, in the sky, when north is up east is left because as you move that way you go over lands to the east. Sagittarian Milky Way (talk) 18:11, 17 February 2013 (UTC)

Brightness and heat

Does anyone have any info indicating the apparent brightness of the meteor, and whether people felt a heat flash from the air-burst? The peak brightness was clearly much greater than the sun, which would suggest apparent magnitude about -27 to -30. Fig (talk) 17:56, 17 February 2013 (UTC)

Many eyewitnesses did report feeling an intense heat coming from the sky during the explosion and accompanying flashes. One eyewitness stated on camera: "A fireball flew by. It got really hot and it dazzled us. We even tried to hide behind the rubbish bins." The woman speaks in Russian but there is a female translator speaking over her. Her on-camera statement can be viewed here: "Russian Meteor strike eyewitness speaks". 1.178.33.170 (talk) 00:18, 18 February 2013 (UTC)

Duplication

Intro "The Chelyabinsk meteor is the largest object known to have encountered the Earth since the 1908 Tunguska event, and the only such event known to have resulted in a large number of injuries"

Damage and injuries "The Chelyabinsk meteor is thought to be the biggest meteor to hit Earth since the 1908 Tunguska event and the only known such event to result in a large number of injuries"

Basically the same sentence twice in the page in different sections - if this this intentional please ignore but I could not see a reason for it. — Preceding unsigned comment added by 92.25.155.165 (talk) 20:24, 17 February 2013 (UTC)

Post airburst fragment

Looks like the first small fragments are being found:

• https://twitter.com/riascience/status/303230959803838464/photo/1
• https://twitter.com/riascience/status/303238753026191360/photo/1

-- Kheider (talk) 21:55, 17 February 2013 (UTC)

Additional details here - http://en.ria.ru/russia/20130217/179531203/Meteorite-Fragments-Found-in-Icy-Urals-Lake---Scientists.html Including quotes from Viktor Grohovsky of the Urals Federal University 'We have just completed the study, we confirm that the particulate matters, found by our expedition in the area of Lake Chebarkul indeed have meteorite nature,” Viktor Grohovsky of the Urals Federal University said. “This meteorite is an ordinary chondrite, it is a stony meteorite which contains some 10 percent of iron. It is most likely to be named Chebarkul meteorite,” Grohovsky said.'

Chondrite - http://en.wikipedia.org/wiki/Chondrite — Preceding unsigned comment added by 92.25.155.165 (talk) 22:31, 17 February 2013 (UTC)

Explosion or sonic boom?

This was briefly mentioned in Archive 1 but not properly discussed.

Most news sources - and this article - talk about an "explosion"... however, all of the videos clearly show the streak disappearing, and not exploding. The trail, even after it gets really bright, simply continues solely in a forward direction and fizzles out. No frills. Not to mention that the NASA page doesn't even mention the word "explosion". I think we ought to rethink the way we have unambiguously and unquestioningly branded the shockwave as an "explosion". BigSteve (talk) 23:06, 17 February 2013 (UTC)

Of course it was an explosion, the light generated by the meteor was plasma at several 1000 kelvin, it expanded and clearly shows a cooling red fireball in photos taken just as it cooled. It was not a sonic boom, it was an airburst, kinetic energy transformed to thermal energy that expanded as a fireball. -Diamonddavej (talk) 23:14, 17 February 2013 (UTC)

There was presumably some sonic boom component as is inevitable from a >7,000 ton item traveling far over Mach 10, but it was dwarfed by the explosion and the shock wave from it. North8000 (talk) 23:19, 17 February 2013 (UTC)

Here's a photo of the cooling fireball, there's also hints of an over pressure shock wave. [10] Also, remember the pre-impact mass was ~10,000 tons, >99% of that was vaporised, transformed into an expanding fireball of gas and plasma. --Diamonddavej (talk) 23:39, 17 February 2013 (UTC)

From everything I read around this I believe the sounds heard were a mix of sonic boom/shock wave and explosion. With luck in time there may be some expert analysis of the audio. Interesting how long the sounds last after the bang on this one: http://www.youtube.com/watch?feature=player_embedded&v=MKx97csfPy0# — Preceding unsigned comment added by 92.25.153.46 (talk) 23:43, 17 February 2013 (UTC)

There was actually a string of sonic booms following the main explosion, as can clearly be heard on videos made of the event. Like a stone skipping across water the meteor was pounding the atmosphere at high velocity and creating sonic booms as it traveled along, breaking up into smaller and smaller pieces. A good method of evaluating this would be to match up the audio signature with the visual signature to get a better understanding of the pattern of explosions. It appears there was a main explosion, followed by two groups of rapid air bursts and a final loud burst, intermingled with dozens of smaller pops and crackles. 1.178.33.170 (talk) 00:46, 18 February 2013 (UTC)

I will be very interested to see what the audio analysis makes of the pops and crackles. After the Tunguska explosion in 1908, people in the vicinity heard what they thought was "cannon fire" for a period after the blast. That is exactly what you hear on the audio of the Chelyabinsk explosion. In fact, on one of the videos, you can hear people yelling in Russian that it's "an artillery bombardment". So what exactly causes these shellfire-like sounds? Is it the noise of smaller fragments exploding? Prioryman (talk) 00:57, 18 February 2013 (UTC)

All the videos I have seen the sounds start with the big bang - nothing before but a lot after including some notable ones. Which might mean something to an expert. Also from the trail looks like it split in two very early then there was a fireball period with possibly further splits too all of which likely accounts for some of the noises. All happening at about 40 times the speed of sound so sonicboom/shockwave in there too. Saw another video from a different city - the sound is more raw, maybe closer - there is a different sound in addition to the bangs, crackles and pops - a roaring fire sound after the first bang at least to my ears http://www.youtube.com/watch?v=64gXz9W2oyQ Will be fascinating to see what a scientist would make of this audio - probably the first time ever this has been recorded after all. — Preceding unsigned comment added by Zeb253 (talk • contribs) 01:31, 18 February 2013 (UTC)

Asked about the "cannon fire" stuff here, in case anyone's interested. Evanh2008 ^{(talk|contribs)} 01:40, 18 February 2013 (UTC)

The explosion is not really visible on the videos simply because it is too bright to capture, the light just "burns through" the video. Some estimate of the brightness can be made from this video by measuring how long it takes for the CCD sensor to recover from the overexposure. -- Petri Krohn (talk) 00:40, 18 February 2013 (UTC)

What kind of temperature are we talking about in the explosion? Has anyone estimated that yet? Prioryman (talk) 01:12, 18 February 2013 (UTC)

Composition of meteorite

It would be much appreciated if someone familiar with the situation could add the estimated composition of the meteorite: e.g., the density, metals, etc. If such information is unavailable, then we could add the estimated guesses by scientists based on where the object came from - as many objects in the same regions have similar compositions. If that proves impossible too, then we should state as much. Magog the Ogre (t • c) 23:46, 17 February 2013 (UTC)

This source says it was a stony meteorite of ordinary chondrite with some 10 percent of iron. -- Petri Krohn (talk) 01:03, 18 February 2013 (UTC)

That's great news. It looks very dark, they say it's an ordinary chondrite but it looks quite dark, like a carbonaceous chondrite. Meteorites are usually named after the nearest post office or city, here's Chebarkul post office (Coordinates: 54°58'32"N 60°22'8"E ) [11] --Diamonddavej (talk) 01:22, 18 February 2013 (UTC)

10000 tons is wrong

I know NASA wrote that but has anyone even tried to think?? That would not be something like 15 meters rock, rather 150 meters rock that would cause a global devastation

Just think of something enormous like http://en.wikipedia.org/wiki/Caterpillar_797 and that takes only 400 tons! — Preceding unsigned comment added by 80.83.238.17 (talk) 01:14, 18 February 2013 (UTC)

That truck is certainly big but I would expect that most of its volume is actually empty space. For a better comparison, the rock in this news story weighs 340 tons but is far smaller than the truck. We're talking about a very dense compact object here. Prioryman (talk) 01:28, 18 February 2013 (UTC)

It has been bugging me too. There is no way -even with 10% iron content- that a 17m meteor had a mass of 10,000 tons. The typist must have mixed kg with tons. BatteryIncluded (talk) 01:30, 18 February 2013 (UTC)

Look at it the other way round, though. Assume a spherical object 17m in diameter with a mass of 10,000 tons. What would its density be? Is that density consistent with known densities for meteorites and asteroids? Prioryman (talk) 01:41, 18 February 2013 (UTC)

A 10,000 ton Ordinary Chondrite, at a typical density of 3.4 tons per cubic meter, would form a sphere 17.8 metres wide (2941 cubic metres). --Diamonddavej (talk) 01:46, 18 February 2013 (UTC)

Nearly all European and Russian news agencies are continuing to claim the object weighed '10 tons' in spite of NASA's claims to the contrary. It appears that the majority of news reports continue to quote '10 tons' and any reference to '10,000 tons' is often quoted as a 'NASA rough estimate'. Russian scientists also continue to claim the object weighed 10 tons. It appears there is still no official consensus as to the actual weight of the object, regardless of any bias towards NASA. 1.178.33.170 (talk) 01:48, 18 February 2013 (UTC)

Right, look at the comments on that NASA news release. The public is giving them sh!t for that 10,000 ton typo. BatteryIncluded (talk) 04:24, 18 February 2013 (UTC)

A 10 ton rock would only be about the size of a couch. I'd guess that was an early estimate from the Russians that hasn't been updated, or if it was, then the update hasn't been reported. Prioryman (talk) 01:52, 18 February 2013 (UTC)

The Russian figure of 10 tons is a joke. A 10 ton object would have to travel at 647 kilometres per second (2.3 million km an hour) to carry 500 kilotons of potential energy! It's a pity news sources insist on quoting this inaccurate figure. --Diamonddavej (talk) 02:07, 18 February 2013 (UTC)

For 10 tons and a density of 5 grams/cubic cm, I think I calculated a sphere with a diameter of 1.7 meters. So if it is 10,000 tons, that would be 17 meters. Bubba73 ^{You talkin' to me?} 02:58, 18 February 2013 (UTC)

A kiloton is 4.184E12 joules. The kinetic energy of a 10,000-ton object traveling at 18,000 meters/sec is 1.62E15 joules, or 387 kilotons. In the ballpark. Bubba73 ^{You talkin' to me?} 03:37, 18 February 2013 (UTC)

There is no way -even with 10% iron content- that a 17m meteor had a mass of 10,000 tons. The typist must have mixed kg with tons, since there is no scientific controversy on its mass. A difference of 3 orders of magnitude cannot be ignored and would be debated at the highest level, which is not happening, but in Wikipedia. Some sourcess citing 10 tons:

• "'Panic' as 10-tonne meteor in Russia's Chelyabinsk region injures more than 500". Associated Press. The Montreal Gazette. 15 February 2013. Retrieved 2013-02-18.
• "PHOTOS: Russia Meteor Explosion Shatters Windows, Injures Hundreds". Time. 15 February 2013. Retrieved 2013-02-18.
• "Meteor injures at least 1,200 in Russia". The Washington Post. 15 February 2013. Retrieved 2013-02-18. {{cite news}}: |first= missing |last= (help)
• The Guardian: [12]
• Washington Post: [13]
• Huffington Post: [14]
• Reuters: [15].
• Fort Worth Star Telegram [16]

Is it a typo or a case of he said/she said? No. It is about science (the one concerned with the universal laws of physics). No original research here, only a factual estimate using simple math: A 17 m diameter meteor would have a ≈ 2570 m³ volume. Since 1 kg of solid iron has a volume = 0.127 m³ and assuming that the meteorite was 100% iron, then 2570 m³ / 127 = 20 tons. Note that this meteor was likely composed of about 10% iron, bringing the mass estimate significantly below 20 tons, and certainly NOWHERE near 10,000 tons. I can’t be more precise and objective than this. Cheers, BatteryIncluded (talk) 03:05, 18 February 2013 (UTC)

You're having a confusion of liters and cubic meters. a 17 m sphere contains 2,572 cubic meters. Each cubic meter (at density 1) is a ton - that's the definition. So if that asteroid had been pure water, it would have been 2,500 tons. 10,000 tons is entirely reasonable for iron (albeit a bit high for carbonaceous chondrite). Tarl.Neustaedter (talk) 03:24, 18 February 2013 (UTC)

My calculations are correct. A 17 m diameter sphere = 2570 m³ volume EXACTLY. Not 2572 m³

It is kind of unusual for a multiplication by pi to result in an exact integer. :-) Bubba73 ^{You talkin' to me?} 04:10, 18 February 2013 (UTC)

Touche! :-) BatteryIncluded (talk) 04:22, 18 February 2013 (UTC)

The units I use are m³, not liters. 10,000 tons is entirely reasonable for iron?? Did you bother to look up the (invariable) density of iron? BatteryIncluded (talk)

Yup. Density of iron is around 8 gm/cc³. That's 8 kg/liter, or about 8 tons/m³. You're confusing cubic meters with liters (which are cubic decimeters). Tarl.Neustaedter (talk) 03:45, 18 February 2013 (UTC)

Meteorites have densities > 3 grams/cm³. That is 3,000 kg/m³. Although I think your figure of 2570 m³ is a little high, that works out to 7,700 metric tons. Bubba73 ^{You talkin' to me?} 03:28, 18 February 2013 (UTC)

Meteorites vaporize about 95% of their content upon entry in the atmosphere, so what you pick up are droplets of molten iron and other metals. The density of a meteor before vaporization is significantly lower. If you think that 2570 m³ is not the volume of a 17 m diameter sphere, then I can't use your feedback for this article. Cheers, BatteryIncluded (talk) 03:43, 18 February 2013 (UTC)

V = 4/3 pi r^3 ... 4/3 * 3.14159 * 8.5³ gives 2572.43 m³. But we're in violent agreement that 10,000 tons is order-of-magnitude reasonable for 17m. Tarl.Neustaedter (talk) 03:33, 18 February 2013 (UTC)

Whoops, I forgot the 4/3! Also, 3 grams/cc is a little low, but also asteroids are oblong rather than spheres. Bubba73 ^{You talkin' to me?} 03:38, 18 February 2013 (UTC)

The Hoba meteorite is 2.7 by 2.7 by 0.9 meters, it weighs 60 tons. --Diamonddavej (talk) 03:47, 18 February 2013 (UTC)

Meteor density ≠ meteorite density. BatteryIncluded (talk) 04:12, 18 February 2013 (UTC)

Let me try it this simple way: a 17 m sphere = 2570 m³, and the density of iron = 7159 kg/m³ therefore, (2570 m³ * 7159 kg/m³) / 1000 kg per ton = 18 tons (assuming again the meteor was 100% iron. Now, go back to the NASA reference, where the public is trashing them for the same typo. BatteryIncluded (talk) 04:12, 18 February 2013 (UTC)

When I multiply 2570 by 7159, I get 18,398,630. That would be kilograms. Dividing by 1000 kg/ton gives 18,398 tons. Bubba73 ^{You talkin' to me?} 04:21, 18 February 2013 (UTC)

If the volume is 2572m³, then the density need only be 4 tons/m³ to get to 10,000. Since the density of iron is a little over 8.6 tons/m³, the figure is quite reasonable. ► Belchfire-TALK 04:27, 18 February 2013 (UTC)