Talk:Chelyabinsk meteor/Archive 3

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Archive 1 Archive 2 Archive 3

Asteroid Origin

A rough origin for the asteroid was announced today via arXiv:
(ordered from pure source down to news articles about it)

  1. http://arxiv.org/abs/1302.5377
  2. http://www.technologyreview.com/view/511691/astronomers-calculate-orbit-of-chelyabinsk-meteorite/
  3. http://www.bbc.co.uk/news/science-environment-21579422
  4. http://news.discovery.com/space/asteroids-meteors-meteorites/russian-meteor-analysis-orbit-apollo-asteroid-130226.htm


I'll let you guys hash out working this into the article. (novice/time constrained) 00:05, 26 February 2013 (UTC)

Most of that has been in the article since Feb 22nd. -- Kheider (talk) 00:32, 27 February 2013 (UTC)
Would it make sense to add the arxiv.org data to the table someone put together, a couple of sections above this one in the Orbital parameters subsection on the Talk page? My orbital mechanics fu is insufficiently strong to know if that is a good idea or not. N2e (talk) 13:21, 27 February 2013 (UTC)
http://arxiv.org/abs/1302.5377 is Zuluaga (2013) -- Kheider (talk) 13:33, 27 February 2013 (UTC)

Lead Sentence

None of our sources says meteoroid. If that edit is repeated without sources and consensus I will report it as edit warring. μηδείς (talk) 16:19, 18 February 2013 (UTC)

Before it encountered our atmosphere is was an asteroid not a meteoroid, it was 17 metres wide. Rubin & Grossman (2010) [1] wrote "However, object 2008 TC3, which dropped fragments of the anomalous ureilite Almahata Sitta in northern Sudan on October 7, 2008, was considered to be an asteroid (Jenniskens et al. 2009) despite the fact that its diameter was 4.1 ± 0.3 m." They propose a meteoroid is "... a 10-μm to 1-m-size natural solid object moving in interplanetary space." --Diamonddavej (talk) 16:50, 18 February 2013 (UTC)
I fully understand the rationale, the object was not a meteor in space. I happen to think keeping meteor but changing the verb from entered to appeared is a better solution--the asteroid/meteoroid stuff is just a little too complex for the lead sentence itself. μηδείς (talk) 16:55, 18 February 2013 (UTC)
Meteors are shooting stars below Mag -4, above Mag -4 it's officially termed a Fireball (a brighter than any planet). There are also unofficial terms, Bolide for fireballs between Mag -14 to -17 and Superbolides for fireballs above Mag -17. The Russia event was brighter than the Sun, > Mag -26, so it must be called a Fireball (or a Superbolide). --Diamonddavej (talk) 17:28, 18 February 2013 (UTC)
I'd plump for Megabolide myself... Prioryman (talk) 20:56, 18 February 2013 (UTC)
Arguments here are irrelevant. We go by reliable sources, not arguments and editorial opinions. I tried a compromise mentioning bolide, asteroid and meteor. That was reverted by an editor who apparently didn't even read the second sentence of the article.[2] I have warned him as already having violated 4RR if not 5RR. I suggest other editors here look at what I have done and support it, or we could just go back to meteor as the sources say. μηδείς (talk) 06:12, 19 February 2013 (UTC)
Regarding my supposed edit warring, you appear to be unaware of the following (all from WP:Edit warring): "A series of consecutive saved revert edits by one user with no intervening edits by another user counts as one revert." Also: "Reverting obvious vandalism" is "not counted as reverts for the purposes of 3RR" (one of my reverts). Also, "Considerable leeway is also given to editors reverting to maintain the quality of a featured article while it appears on the main page." Your accusation that I engaged in edit warring is nonsense.
Also, I did read (and edit) the second sentence. The current version is problematic; it suggests that the object did not become a fireball until it exploded, which is misleading. It became a fireball as soon as it attained the requisite level of luminosity. "Fireball" is the most accurate term for the object as it was under observation, and it would be appropriate to include it in the opening sentence. WolfmanSF (talk) 10:39, 19 February 2013 (UTC)
Here is NASA's official explanation as to the differences between an asteroid, comet, meteoroid, meteor and meteorite... "In space, a large rocky body in orbit about the Sun is referred to as an asteroid or minor planet whereas much smaller particles in orbit about the Sun are referred to as meteoroids. Once a meteoroid enters the Earth's atmosphere and vaporizes, it becomes a meteor (i.e., shooting star). If a small asteroid or large meteoroid survives its fiery passage through the Earth's atmosphere and lands upon the Earth's surface, it is then called a meteorite. Cometary debris is the source of most small meteoroid particles. Many comets generate meteoroid streams when their icy cometary nuclei pass near the Sun and release the dust particles that were once embedded in the cometary ices. These meteoroid particles then follow in the wake of the parent comet. Collisions between asteroids in space create smaller asteroidal fragments and these fragments are the sources of most meteorites that have struck the Earth's surface." The original source for this quote can be found here. 1.178.161.116 (talk) 06:42, 19 February 2013 (UTC)

────────────────────────────────────────────────────────────────────────────────────────────────────A Fireball is bright meteor. An air burst is the destruction of said meteor/asteroid. After the air burst, remains of the asteroid will enter dark flight. -- Kheider (talk) 11:02, 19 February 2013 (UTC)

I support using asteroid instead of meteoroid here. It is simply too large to be considered a meteoroid (traditionally up to 10 meters). Svmich (talk) 13:53, 19 February 2013 (UTC)
I too support the use of asteroid instead of meteor or meteoroid in the leading sentence; meteoroid is incorrect, per scientific nomenclature. -BatteryIncluded (talk) 20:11, 19 February 2013 (UTC)
What do the expert SOURCES call it? It matters not what our opinions are. WP:VERIFIABILITY, NOT TRUTH. On the other hand, if the scientists determine what to officially call it, they got it right. :-) HammerFilmFan (talk) 22:14, 19 February 2013 (UTC)
A meteoroid is defined as a small asteroid up to 1 meter in diameter. (Source: Rubin, Alan E.; Grossman, Jeffrey N. (January 2010). "Meteorite and meteoroid: New comprehensive definitions". Meteoritics & Planetary Science 45 (1): 114–122. Bibcode:2010M&PS...45..114R. doi:10.1111/j.1945-5100.2009.01009.x.  )
NASA's explanation fails to say what an asteroid breaking up within the atmosphere is called, only that the end product is a meteorite. Out in space, an object may be a meteoroid, asteroid, comet, or minor planet depending both on size and composition. There seems to be no single official upper limit for the size of a meteoroid; various places quote 1 cm, 10 cm or 1 metre. In the atmosphere the streak of light emitted from the former meteoroid or asteroid is called a meteor, fireball or bolide depending on brightness. The bits found on the ground are meteorites. -- 79.70.229.101 (talk) 17:37, 20 February 2013 (UTC)

Lead: Meteor, asteroid vs. meteoroid

In addition of the low-grade edit warring, there are about 4 distinct threads in this large talk page where we are discussing the use of the words asteroid, meteor vs. meteoroid in the leading sentence:

Please, let's reach a rational consensus under a single thread. Cheers, BatteryIncluded (talk) 20:37, 19 February 2013 (UTC)

184.158.96.147 (talk) 16:20, 21 February 2013 (UTC)
  • Asteroid — the object that entered Earth's atmosphere from space is clearly an asteroid due to both its size—much larger than a meteoroid (by any of the accepted definitions)—AND due to the origin in the main asteroid belt. However, the second item need not be true to lead Wikipedia to refer to it by the more correct title, now that we know its size. (and meteor is incorrct as that is merely the observable optical phenomenon once the space rock (asteroid or meteoroid) enters the atmosphere. N2e (talk) 22:02, 21 February 2013 (UTC)
Fine, but don't give us your argument. Give us a reliable source. μηδείς (talk) 22:19, 21 February 2013 (UTC)
The editor who made the comment prior to mine provided about a half dozen references on the matter. Just read them, and feel free to find others. But all the training I've had in this area, and the sources recently identified by numerous commenters on this Talk page, point to meteoroids beings small chunks, generally less than about 1 m in breadth, off of comets or asteroids. With the current consensus on the Chebylinsk event being that the item was 17 m prior to the air burst, it is quite simply, not a meteoroid. Cheers. N2e (talk) 01:48, 22 February 2013 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── It seems we have a consensus: asteroid!

The lede currently refers to the optical phenomenon as a meteor (correct) but then (incorrectly) states "it quickly became a brilliant fireball as it passed over the southern Ural region, exploding in an air burst over Chelyabinsk Oblast...". I think it would be fair to consider the fireball a part of the (optical) meteor phenonmenon; but it seems to me to be incorrect to infer, as that prose does, that the meteor exploded. It did not. The asteroid exploded. Or the asteroid fragment exploded. But meteors, being merely an optical phenomenon, don't explode; rather, the basic celestial object, that was manifesting itself in the optical meteor by entering Earth's atmosphere is what exploded. Thoughts? N2e (talk) 01:32, 26 February 2013 (UTC)

Proposed change based on the consensus above (to be further edited by anyone)

On 15 February 2013, an asteroid entered the Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).(refs.) Travelling at about 18 km/sec (40,000 mph),(refs.) it quickly became a brilliant meteor as it passed over the southern Ural region, exploding in an air burst over Chelyabinsk Oblast at about 15 to 25 km (9.3 to 15.5 mi) above the ground.(refs.)

Please correct and edit further. BatteryIncluded (talk) 16:03, 26 February 2013 (UTC)
The asteroid (not meteoroid, and certainly not meteor or meteorite) entered the atmosphere and became a fireball (or bolide, i.e. a bright meteor - IAU designate this a "superbolide") and it then exploded creating the meteorites (not meteors, not meteroids) later found on the ground. -- 212.139.104.161 (talk) 11:44, 27 February 2013 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── Here's a slight modification of the suggested text, taking ideas from both of the above suggestions:

On 15 February 2013, an asteroid entered the Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).(refs.) Travelling at about 18 km/sec (40,000 mph),(refs.) it quickly became a brilliant superbolide meteor as it passed over the southern Ural region, exploding in an air burst over Chelyabinsk Oblast at about 15 to 25 km (9.3 to 15.5 mi) above the ground,(refs) creating a number of small fragmentary meteorites subsequently found on the ground.

Please correct and further refine, or be bold and insert the text into the lede based on the consensus. N2e (talk) 13:14, 27 February 2013 (UTC)

Further edit:
On 15 February 2013, an asteroid entered the Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).(ref) Travelling at about 18 km/sec (40,000 mph),(ref) it quickly became a brilliant superbolide meteor as it passed over the southern Ural region. It exploded in an air burst over Chelyabinsk Oblast at about 15 to 25 km (9.3 to 15.5 mi) above the ground,(ref) creating a number of small fragmentary meteorites and a powerful shock wave.(ref)
-BatteryIncluded (talk) 15:40, 27 February 2013 (UTC)
I think that is great,as well as supported by the sources and the science. N2e (talk) 00:36, 28 February 2013 (UTC)
"superbolide meteor"... "superbolide" is a "very bright meteor"; "meteor" is redundant. -- 212.139.104.161 (talk) 09:57, 28 February 2013 (UTC)
You are correct. The redundancy is because user μηδείς (aka: Medeis) is hell-bent on deleting the use of asteroid in the opening sentence. Whatever the refererences (experts) say, he is in denial that it was an asteroid, so he keeps inserting "meteor". I am tying to please him so I moved "meteor" after superbolid. Please feel free to address both Medeis and that redundancy. Cheers, BatteryIncluded (talk)
Thanks BattInc, I like the intro lede much better now.
On the point of having "meteor" there, I would say as a matter of esoteric technical English, it is redundant to say "superbolide meteor". However, since the vast majority of our readers are reading this article as non-technical and non-space-geek people, I think it is probably quite useful to use superbolide as a(n unfamiliar) adjective for the term meteor to help the lay readers get what the article is all about. Cheers. N2e (talk) 23:53, 28 February 2013 (UTC)

Article title

This discussion has been closed in favor of a formal move request below. If you have not already voted in this formal request please do so

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Is it time to change the article title to Chelyabinsk meteor? --PlanetEditor (talk) 05:15, 19 February 2013 (UTC) See below. --PlanetEditor (talk) 01:48, 20 February 2013 (UTC)

UPDATE: A better and more appropriate title is Chelyabinsk meteor event. --PlanetEditor (talk) 13:05, 19 February 2013 (UTC)
  • Strong support for Chelyabinsk meteor event.. --Guy Macon (talk) 05:27, 19 February 2013 (UTC)
  • Strong support. The meteor bolide is depositive. kencf0618 (talk) 06:57, 19 February 2013 (UTC)
  • Support. Evanh2008 (talk|contribs) 07:01, 19 February 2013 (UTC)
  • The designation "Chebarkul meteorite" refers to the recovered fragments of the meteorite, not the event of the meteor impact and the damage that resulted to the city of Chelyabinsk. --Mike Agricola (talk) 15:57, 19 February 2013 (UTC)
  • Weak Support The name will do for the time being. It will likely be called the Chelyabinsk event or similar in due course amongst the scientific community, as this name will encompass the entire event from meteoroid, meteor, blast wave and meteorite recovery etc. --Diamonddavej (talk) 08:35, 19 February 2013 (UTC)
  • Support: A quick Google News search on the phrase "2013 Russian meteor" returned four results with that exact phrase. In contrast, Google News reports 2610 results containing the exact phrase "Chelyabinsk meteor." Per WP:COMMONNAME, I support the proposed name Chelyabinsk meteor event. --Mike Agricola (talk) 15:57, 19 February 2013 (UTC)
I'm sorry, but you just can't use news searches for current events like that. Unlike Wikipedia, current news reports have an implicit year - anything you search for prefixed by its year will get few to no hits. Prefixing or suffixing a year is only done when you're referencing past events (e.g. "The 2008 Examplian Election") or when you're naming something for archival use - like on Wikipedia. Kolbasz (talk) 03:50, 20 February 2013 (UTC)
  • Support for the title Chelyabinsk meteor event. The main subjet of this article is the event, its timeline, the destruction and responses, not the physical asteroid or the Chebarkul meteorite. BatteryIncluded (talk) 16:01, 19 February 2013 (UTC)
  • Comment I prefer "event" in there somewhere, because the article is mostly about the whole event, not just the meteor itself. Bubba73 You talkin' to me? 17:35, 19 February 2013 (UTC)
  • Support Chelyabinsk... This thing was never a meteor; it was an asteroid in space, a bolide (or super, megabolide) when seen in the atmosphere. One part in ten billion of it was found as a one gram meteorite. The correct title would be Chelyabinsk asteroid impact or Chelyabinsk asteroid impact event. Do not expect there to be words for this in the everyday vocabulary. This kind of thing has only happened once in recorded history. At that time less than a handful of people actually saw it. It took almost 90 years for people to understand what it was. -- Petri Krohn (talk) 17:55, 19 February 2013 (UTC)
Of course it was a meteor - that's basic astronomy. When it was in the atmosphere burning up, it's a meteor. The other stuff are sub-categories. HammerFilmFan (talk) 22:20, 19 February 2013 (UTC)
  • No, it's hardly the only name tied to the event. As pointed out below, Chelyabinsk is not even the main location of the event. It occurred throughout a wide area, not restricted to the city even if the bolide impact zone was located in the city. - M0rphzone (talk) 00:27, 20 February 2013 (UTC)
  • I pointed out "that town is forever linked to this event," never saying its name should be used for title. I simply suggested that the article title should be treated accordinly. Whatever name you guys choose, the matter here shouldn't be just the choosing of a name. This article is part of many others and definitely, is not a matter of preference. Besides, I have seen many articles change names overnight. Krenakarore TK 19:41, 20 February 2013 (UTC)
  • Comment I'd suggest the article be named 2013 Chelyabinsk Meteor Event or 2013 Chelyabinsk Fireball Event or something similar, with a redirect from 2013 Russian meteor event redirecting here, unless there is another event over Russia this year. It wasn't a meteor strike, only a blast wave that was focused/combined with shock wave and sonic boom that caused the damage.Wzrd1 (talk) 20:59, 19 February 2013 (UTC)
  • Oppose 2013 Russian meteor event is a pretty good interim title, and Chelyabinsk meteor is not better as an interim title. Rationale: 1) this is not a local event that is entirely, or even mostly, limited to Chelyabinsk; 2) the scientists are already debating on what to call the thing, but "meteor" is not the most usual title for this sort of large chunk that is an air bursting bollide or superbollide. For example, the guy who is the author of the asteroid "bible", Dr. John S. Lewis, a professor of planetary science, had this to say about the Russian "meteor":

This was not a meteor. A meteor is an optical phenomenon, a flash of light seen in the sky when a piece of cosmic debris (usually dust- or sand grain-sized) enters Earth’s upper atmosphere, converts its huge kinetic energy into heat, and “burns up” (vaporizes), usually at an altitude of at least 100 km. The Chelyabinsk object was a fragment of asteroidal or cometary origin, probably several meters in diameter, properly called a “meteoroid” or, more loosely, a “small asteroid”. A brilliant fireball seen in the atmosphere is called a bolide. Some bolides, caused by entry of large pieces of hard rock, drop meteorites on the ground: a meteorite is a rock of cosmic origin that reaches the ground in macroscopic pieces (not dust or vapor). (link here)

So I oppose the proposed change for those two reasons. N2e (talk) 22:55, 19 February 2013 (UTC)
  • When a meteoroid enters atmosphere, it is called meteor. And meteor events are generally named according to the place where they impact. --PlanetEditor (talk) 01:46, 20 February 2013 (UTC)
  • Oppose: Event wasn't localized just to Chelyabinsk (a better, more localized version instead of "Russian meteor/event" would be "Urals meteor/event"), and there's absolutely no consensus in the media or other places to call it the "Chelyabinsk meteor/event". Looking at Google hits, "Russian meteor" beats the other ones hands down - "Chelyabinsk meteor" gets 97,400 hits, "Chelyabinsk event" 7,240, but "Russian meteor" together with qualifiers such as "Chelyabinsk" and "2013" get tens of millions of hits (e.g. "russian meteor" "chelyabinsk" "2013" gets 27,700,000 hits. Kolbasz (talk) 03:38, 20 February 2013 (UTC)
  • I'm opposed to the word "event" in the title. It's too woosy. A thousand people injured. That's an emergency, catastrophe, calamity. An EVENT is a Celine Dion concert, or Grampa's bed collapsing in the middle of the night and the ensuing ruckus so complex only Thurber can explain it. The term "event" doesn't carry the connotation of a terrible disaster, cataclysm, holocaust, tragedy, 'fell stroke', bane, or woe. It is a more friendly kind of thing, like a misadventure, upset, debacle, or fiasco. Friendly Person (talk) 15:00, 20 February 2013 (UTC)
Comment I think event is fine, there were no deaths (I know of) some windows broke, a single roof collapsed, it is not an "emergency, catastrophe, calamity" nor do the words " terrible disaster, cataclysm, holocaust, tragedy, 'fell stroke', bane, or woe" describe the event. CombatWombat42 (talk) 15:10, 20 February 2013 (UTC)
  • Support "Chelyabinsk meteor event" "Chelyabinsk" (assuming / conditional on that that is the name that caught on ) is more specific than "Russian", "meteor" is a common name for this, and event is a good noun to encompass it all (effects etc.) North8000 (talk) 15:15, 20 February 2013 (UTC)
  • Strongly opposed to event, it's against MOS and simplicity. Chelyabinsk meteor is perfectly fine
We've got 82 news sources at google calling this the "Chelyabinsk meteor" and one source, "Chessbase", (hardly a notable reliable source for such things) calling it the Chelyabinsk meteor event. μηδείς (talk) 21:23, 20 February 2013 (UTC)
  • Oppose "event" in the title. This use of the word "event" is pointless. The Tunguska event was only called that because nobody was sure what it was. Calling this meteor a "meteor event" is like calling an "assassination" an "assassination event". Abductive (reasoning) 22:01, 21 February 2013 (UTC)
    Agree 100% on Tunguska. Besides, meteor in fact means meteoroid event. -- Petri Krohn (talk) 03:36, 22 February 2013 (UTC)
    That's right, there was speculation around 1960 that the T. Event was caused by a kilgram of antimatter. Nobody knew what it was, no meteorite material — Preceding unsigned comment added by Friendly person (talkcontribs) 03:24, 23 February 2013 (UTC)
  • Strong support for "Chelyabinsk meteor" or even "Chelyabinsk meteorite". Kondormari (talk) 08:10, 25 February 2013 (UTC)
  • Support "Chelyabinsk meteor event"Joncolvin (talk) 08:45, 27 February 2013 (UTC)
  • Strongly oppose "event" in the title. Redundant, unnecessary, verbose. -- Dan Griscom (talk) 03:16, 1 March 2013 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.


Reference 18

This "the only meteor known to have resulted in a large number of injuries" is not stated in reference 18. Where did it come from? — Preceding unsigned comment added by 123.211.29.185 (talk) 03:07, 1 March 2013 (UTC)

Give a direct diff or a quote of the source if you want an answer. μηδείς (talk) 03:43, 1 March 2013 (UTC)

http://www.nature.com/news/russian-meteor-largest-in-a-century-1.12438 — Preceding unsigned comment added by 123.211.29.185 (talk) 03:50, 1 March 2013 (UTC)

Test. 184.158.96.147 (talk) 04:08, 1 March 2013 (UTC)
Looks like the reference was misplaced, appearing a few words later than intended. Moved it back a few words and added a different reference (and fixed a typo). -- 212.139.104.161 (talk) 05:04, 1 March 2013 (UTC)

meteor

I am not quite sure how many times I need to mention that the lead sources refer to this as a meteor as it enters the atmosphere. Those sources have been mentioned endlessly and have not been deleted. Please refrain from pointy deletion of the link to the meteor article. μηδείς (talk) 03:41, 1 March 2013 (UTC)

Damage clarification still needed

RUSSIAN CONTRIBUTORS, can you assist? The second paragraph of the Damages and Injuries section provides (reliably sourced): "...."3,724 apartments, 671 educational institutions, 69 cultural facilities, 34 hospitals and clinics, 11 social facilities and five sport venues in the Chelyabinsk region..." that needed repairs as a result of the shock wave damage. Approximately 100,000 or so homeowners were affected according to Mikhail Yurevich...".

The list of damaged buildings was copied verbatim from the English news report. Some elaboration or clarification is needed: are the 3,724 apartments referring to apartment buildings, or to the separate apartment units within apartment buildings? If the latter, then the number of damaged apartment buildings would be significantly smaller. The other clarification required is for the vague 100K 'homeowners'; what type of buildings were these homes, condo units or stand-alone single-family homes, or a mix of both? I suspect the Russian or Chelyabinsk Region emergency authorities maintain a centralized listing of this data, and it would be good to access it for the latest figures as well. Best: HarryZilber (talk) 18:33, 1 March 2013 (UTC)

Sonic Boom

There is widespread misreporting that the shock wave / damage was caused by a "sonic boom" (as opposed to fact that the damaging shock wave was due to the 500 KT air burst explosion). Sonic boom reported extensively across many media outlets. Attempted to add a note correcting erroneous reportage to this effect in "Media coverage" which was immediately reverted by John without comment or explanation. Since this is still a widespread and ongoing misconception (google search of "russian meteor "sonic boom"" returns 745,000 entries) this should be noted on the page. However not clear if this should go in "Atmospheric entry", "Damage" or "Media coverage". Comments please.Joncolvin (talk) 20:06, 24 February 2013 (UTC)

The term "sonic boom" is not used anywhere in the article. μηδείς (talk) 21:21, 24 February 2013 (UTC)
Not anywhere in this article, but term used widely and erroneously across many media outlets. Eg New York Times, http://www.nytimes.com/2013/02/16/world/europe/meteorite-fragments-are-said-to-rain-down-on-siberia.html?pagewanted=all&_r=0, Slate magazine, Daily Mail UK http://www.dailymail.co.uk/news/article-2281454/Dramatic-video-captures-moment-sonic-boom-Russian-meteor-terrifies-schoolchildren-smashing-windows-sports-hall.html?ito=feeds-newsxml, Space.com etc etc etc. Reporting error sufficiently widespread and repetitive it should be noted.Joncolvin (talk) 07:06, 25 February 2013 (UTC)
I don't think that the purpose of this encyclopedia is to list the events that were not. Stating that the shock wave was caused by the air burst of a meteor, takes care of everything else, including sonic booms, angry birds angry gods, or an American weapon test. Cheers, BatteryIncluded (talk) 13:07, 25 February 2013 (UTC)
If it was widely reported that the shock wave was caused by angry birds that would certainly be notable. The notability is the WIDESPREAD misreporting (hence entry in media coverage that John reverted), not the non-existent sonic boom. For example: http://news.discovery.com/space/asteroids-meteors-meteorites/falling-meteor-packed-a-sonic-punch-130215.htm amongst many other. I'm not sure why you think this isn't notable. Joncolvin (talk) 08:28, 27 February 2013 (UTC)
I don;t think it is notable because 1) It is not "widespread" in the media, and 2) it is not a scientific (or a popular) controversy. For example, some nespapers' headlines were "Russia hit by meteorites" or "Meteorites injure 1000 people". We don't quote the attention-grabbing title, but the verifiable facts in the text. Cheers, BatteryIncluded (talk) 20:16, 27 February 2013 (UTC)
It is not our place to decide whether there was "widespread misreporting" We just report what is in the sources.
"If Wikipedia had been available around the fourth century B.C., it would have reported the view that the Earth is flat as a fact and without qualification. And it would have reported the views of Eratosthenes (who correctly determined the earth's circumference in 240BC) either as controversial, or a fringe view. Similarly if available in Galileo's time, it would have reported the view that the sun goes round the earth as a fact, and Galileo's view would have been rejected as 'original research'. Of course, if there is a popularly held or notable view that the earth is flat, Wikipedia reports this view. But it does not report it as true. It reports only on what its adherents believe, the history of the view, and its notable or prominent adherents. Wikipedia is inherently a non-innovative reference work: it stifles creativity and free-thought. Which is a Good Thing." --WP:FLAT
--Guy Macon (talk) 21:14, 3 March 2013 (UTC)
We also need to keep in mind Wikipedia:SCIRS: "news articles should be used with caution when describing scientific results". If some sources are clueless/obsolete, we do not need to keep repeating them. -- Kheider (talk) 21:28, 3 March 2013 (UTC)
Unlike the debate on the shape of the Earth in the 4th century, the physics of a falling meteor are well known today: Sonic booms do not cause explosive (air burst) shock waves. BatteryIncluded (talk) 22:39, 3 March 2013 (UTC)
...which of course means that we can easily find a citation to a reliable secondary source that says that. Where WP:FLAT comes into play is when a editor wants to insert WP:OR or WP:SYNTH into an article. --Guy Macon (talk) 00:27, 4 March 2013 (UTC)

Requested move 2013 Russian meteor eventChelyabinsk meteor

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: Moved to Chelyabinsk meteor Mike Cline (talk) 14:05, 4 March 2013 (UTC)



2013 Russian meteor eventChelyabinsk meteor – Please see the discussion Talk:2013_Russian_meteor_event#Article_title above where there is strong support for this move, minus the extraneous "event". please note that 2013 Russian meteor event gets 48,600 hits at Google and zero hits at Google News, while "Chelyabinsk meteor" gets 209,000 hits at Google and 65 hits at Google News. μηδείς (talk) 19:19, 24 February 2013 (UTC)

Once again, you can't use news searches like that. See my reply to Mike Agricola at Talk:2013_Russian_meteor_event#Article_title. Kolbasz (talk) 18:58, 26 February 2013 (UTC)
  • Support There has already been strong support for this, minus the extra word "event" in the previous unclosed informal discussion above. The item is off ITN now, Google news prefers "Chelyabinsk meteor" 65 to 0 against "2013 Russian meteor event", and the change should not be disruptive at this point. μηδείς (talk) 19:22, 24 February 2013 (UTC)
  • Support -- Kheider (talk) 19:45, 24 February 2013 (UTC)
  • Support: At least it gets rid of the awful "event". Skinsmoke (talk) 20:47, 24 February 2013 (UTC)
Agreed, "Chelyabinsk meteor event" gets a whole 1 hit at Google News and some 10,000 at google, compared to 200,00 for "Chelyabinsk meteor". μηδείς (talk) 21:17, 24 February 2013 (UTC)
  • "Event" was fine when the news, some of which contradicted one another, started pouring in, but at this point "Chelyabinsk meteor" is a fairly established moniker. Support.—Ëzhiki (Igels Hérissonovich Ïzhakoff-Amursky) • (yo?); February 25, 2013; 14:51 (UTC)
  • Support. This use of the word "event" is pointless. The Tunguska event was only called that because nobody was sure what it was. Calling a meteor a "meteor event" is like calling an assassination an "assassination event" or an election an "election event". Abductive (reasoning) 21:52, 25 February 2013 (UTC)
  • Support Sure, that works. That's where the sourced point, so let's follow them.... Sailsbystars (talk) 22:03, 25 February 2013 (UTC)
  • Support Why hasnt this happened yet? Fig (talk) 13:01, 26 February 2013 (UTC)
  • Oppose. Event wasn't localized to Chelyabinsk, and news sources and online discussion vastly favor "Russian meteor" over "Chelyabinsk meteor". Kolbasz (talk) 18:59, 26 February 2013 (UTC)
  • Oppose. (NOTE: I don't have time to look for it just now, but there was a previous proposal to change the name of this article, and I believe it was on this Talk page. It got several "support" comments and several "oppose" comments. Don't know where those comments, or that discussion went because this new section seems to have only one oppose comment prior to the one I am adding now.)
I am opposing this name change as the event was much larger than merely Chelyabinsk, and in fact had a regional effect beyond Russia. For now, as an interim name, I think the 2013 Russian meteor event is still fine. I suspect we will have better science on the facts of the celestial object entry into Earth's atmosphere, as well as a better feel for what it comes to be known as in the popular press, in a few weeks or months. But I'm convinced that Chelyabinsk meteor is a move in the wrong direction. Cheers. N2e (talk) 23:34, 26 February 2013 (UTC)
The prior section is easily found by scrolling up from this one or clicking on the link I gave at the top of this discussion pointing directly at it. It was a confused discussion since a large number of the "opposes" opposed only the adding of "event" to the end of the title when they actually otherwise supported the full move. μηδείς (talk) 20:04, 27 February 2013 (UTC)
There is no need for an interim name any longer, as the article is off the Main Page and page views are down to 1/18th their height. It has already been demonstrated that this stupid word "event" is not at all common. Abductive (reasoning) 12:12, 28 February 2013 (UTC)
In astronomy, the word "event" is routinely used for something that is going to happen or has already happened. Indeed, there's at least one "(astronomy) calendar of celestial events". -- 212.139.104.161 (talk) 12:18, 28 February 2013 (UTC)
And minutes after I made that comment, someone has removed every use of the word "event" from the article, and in some cases replaced it with a word that makes no sense in the context now used. You might think of an "event" as a "concert" or a "match" that you buy tickets for. In astonomy, an "event" is simply something that "happens". -- 212.139.104.161 (talk) 12:40, 28 February 2013 (UTC)
Like an "eclipse event", or a "solar flare event", or an "occultation event"? Abductive (reasoning) 12:57, 28 February 2013 (UTC)
  • Strongly support removing "event" from the title. Redundant, unnecessary, verbose. (Yes, I'm repeating myself, but if you have two ongoing naming polls then I need to vote in both.) -- Dan Griscom (talk) 03:29, 1 March 2013 (UTC)
Clarification on my position: I didn't oppose this move, I opposed the word event in the title, which meant I supported this move. 'Twas confusing: hopefully 'tis no longer. -- Dan Griscom (talk) 18:50, 3 March 2013 (UTC)
  • Support: Chelyabinsk meteor seems more appropriate. This article is about a a meteor and the effects of this meteor were centered on Chelyabinsk area. -- Basilicofresco (msg) 10:49, 3 March 2013 (UTC)
  • Support And re-review in 6 months when we find out what sources are calling it after the dust settles.  :-) North8000 (talk) 18:47, 3 March 2013 (UTC)
  • Oppose. Few English users will be able to remember that name or how to spell it. Bubba73 You talkin' to me? 18:50, 3 March 2013 (UTC)
You do realize that if this move passes anyone who searches for or follows a link to "2013 Russian meteor event" will end up at "Chelyabinsk meteor" (or a disambiguation page if there is another meteor event in Russia this year), right? --Guy Macon (talk) 21:07, 3 March 2013 (UTC)
  • Strong support - "Event" is unnecessary, given that the cause of the fireball and the damage has been positively identified. The opposition arguments based on spelling are vacuous—that's what redirects are for. Evanh2008 (talk|contribs) 18:55, 3 March 2013 (UTC)
  • Support Move, caution editors about using trusting Google results. Naming it "Chelyabinsk meteor" is an obvious improvement. I would caution those who are relying on how many hits they get on Google as evidence, though. Google gives you different results depending on where you live, what you have searched on before, your browser language preferences, etc. You cannot draw a general conclusion from search results that were custom-built just for you. --Guy Macon (talk) 21:07, 3 March 2013 (UTC)
  • Support for now - re-review in 1 year to see how academic sources such as scientific journals are calling it. - M0rphzone (talk) 22:03, 3 March 2013 (UTC)
  • Strong support Succinct and more formal. kencf0618 (talk) 22:20, 3 March 2013 (UTC)
  • I would support: 2013 Russian meteor because no native English speakers will remember the word Chelyabinsk or its spelling. BatteryIncluded (talk) 22:57, 3 March 2013 (UTC)
That's not at question here, editors should only be voting oppose or support for the matter at question. As for your assertion, BI, I am a native English speaker, and I have never wished the Tunguska Event were called the Russian Event. Unique things have unique names, and the redirects will not disappear. μηδείς (talk) 23:04, 3 March 2013 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Estimates published 28 Feb 13 based on nuclear test sensors

(From http://www.cnn.com/2013/02/27/world/europe/russia-meteor)

The duration of the wave—about 32 seconds—let scientists estimate the energy of the blast at between 450 and 500 kilotons, the size of about 30 early nuclear bombs...

The latest estimate is that the Chelyabinsk meteor was about 56 feet (17 meters) across, weighed more than 700,000 tons and was moving about 18 kilometers per second (40,000 mph) when it blew apart...

"the largest since Tunguska"

72.244.206.233 (talk) 10:34, 28 February 2013 (UTC)

(4/3) * pi * (8.5m)^3 = 2752 m^3 (2752 cubic metres).
700000 tonnes / 2572 m^3 = 272 tonnes/m^3 (272 tonnes per cubic metre).
No way! We already know NASA initially said 7700 tons then revised the estimate upwards to 10 000 tons.
2012DA14 is 50 metres across and 150 000 tonnes. An object 17 metres across is going to be a lot LESS than that.
The CNN figure is junk. -- 212.139.104.161 (talk) 11:10, 28 February 2013 (UTC)
As of now—the version "updated 10:37 AM EST, Thu February 28, 2013"—the CNN article says (without any correction acknowledgement):

The latest estimate is that the Chelyabinsk meteor was about 56 feet (17 meters) across, weighed more than 7,000 tons and was moving about 18 kilometers per second (40,000 mph) when it blew apart, she said.

Either the "700,000" was not an accurate cut/paste or CNN quietly "updated" it.
Perhaps the comparison to the Tunguska event, credited to Margaret Campbell-Brown, an astronomer at the University of Western Ontario, remains notable. 67.100.127.116 (talk) 21:40, 28 February 2013 (UTC)
7000 tons is the figure NASA first announced. NASA quickly uprated this to 10 000 tons within hours. It's bad form for CNN to change the article without adding a note. Even with this change, CNN is still two weeks behind. -- 212.139.104.161 (talk) 22:15, 28 February 2013 (UTC)
Further update: 11 000 tonnes - http://neo.jpl.nasa.gov/news/fireball_130301.html -- 212.139.104.161 (talk) 10:08, 3 March 2013 (UTC)

Chelyabinsk meteor superbolide

Meteor is the visible phenomenon when a space rock burns up in the atmosphere.

Bolide or Fireball is a bright meteor. Superbolide is a very bright meteor.

Referring to this, what is a "meteor superbolide"? Surely it's one word or the other, not both?

We don't say 'I rode my motorcycle bike into town and got a car taxi back home'. -- 212.139.104.161 (talk) 16:55, 4 March 2013 (UTC)

Additionally, several uses of the word "meteor" do not make sense in the context used here. -- 212.139.104.161 (talk) 17:48, 4 March 2013 (UTC)
I fixed some. By the way, if you create an account, you can edit this article. Abductive (reasoning) 19:14, 4 March 2013 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── There was a week-long discussion and consensus developed on this topic. See the Talk page section: "Lead sentence" above. On about 2013-02-28T05:... user BatteryIncluded made the changes that were the result of that consensus, as it had been hammered out. The text then read:

"On 15 February 2013, an asteroid(refs) appeared in Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).(refs) Travelling at about 18 km/sec (40,000 mph),(ref) it quickly became a brilliant superbolide meteor as it passed over the southern Ural region.(refs) It exploded in an air burst over Chelyabinsk Oblast at about 15 to 25 km (9.3 to 15.5 mi) above the ground,(ref) creating a number of small fragmentary meteorites and a powerful shock wave."

In my opinion, "superbolide meteor" is about the best and most clear we are going to get consensus on, since so many media sources have used the bare term "meteor" and also because so many non-technical readers of Wikipedia don't know the rather more esoteric scientific terms "bolide" and "superbolide."

Nevertheless, despite that consensus, within a day, someone had removed the consensus "superbolide meteor" text and inserted the term "meteor" back earlier in the sentence, without gaining support for the change on the Talk page. The intro sentences of the lede now reads:

On 15 February 2013, an asteroid[3][4][5] entered Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).[6][7][8][9] With an estimated speed of 18 km/s (40,000 mph),[6] the meteor became a brilliant superbolide over the southern Ural region.[10] It exploded in an air burst over Chelyabinsk Oblast at about 15 to 25 km (9.3 to 16 mi) above the ground,[6][11] creating small fragmentary meteorites and a powerful shock wave.

I have not chosen to get into a revert war about it on the article main page, but will be happy to come back to the Talk page to discuss it further if invited. But I think using "superbolide" to describe and qualify the "meteor", as in "superbolide meteor" is the best idea in the short term. Cheers. N2e (talk) 20:22, 4 March 2013 (UTC)

I have no problem with the current text.
This text: "On 15 February 2013, an asteroid(refs) appeared in Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC).(refs) Travelling at about 18 km/sec (40,000 mph),(ref) it quickly became a brilliant superbolide meteor as it passed over the southern Ural region." is fine, except that it should either be "meteor appeared" or "asteroid entered" (which is current as of this edit). So if it's important I think we should just change the verb to entered, add "the" since we are not speaking Russian, and replace the period with a semicolon: "On 15 February 2013, an asteroid(refs) entered the Earth's atmosphere over Russia at about 09:20 YEKT (03:20 UTC);(refs) travelling at about 18 km/sec (40,000 mph),(ref) it quickly became a brilliant superbolide meteor as it passed over the southern Ural region."
One thing that is not acceptable is not having the word meteor in the lead sentence. Neither the asteroid precursor (which had not even been noticed) nor the meteorites would have any notability if it were not for the fact that this is the most brilliant meteor in recorded history. μηδείς (talk) 20:38, 4 March 2013 (UTC)
I'm sure there's a way this can be worked out to everybody's satisfaction. I made the changes that User:212.139.104.161 asked for because I was the one who changed a lot of the instances of the word "event" to "meteor". I am not wedded to any particular text. Abductive (reasoning) 21:28, 4 March 2013 (UTC)
There are multiple places where either meteor or event would be equally understandable, but a few where meteor made much less sense than event. Those recent changes are now fine. I understand the need to dumb things down a bit, but the word superbolide is linked to a detailed article for those that don't know what it is. A few days ago, someone (can't remember who) cautioned we should "be careful to use the right terminology lest we call a tsunami a 'big wave'". -- 212.139.104.161 (talk) 23:20, 4 March 2013 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── The original point in this talk topic was not about the lead section, but about the text just below the orbital parameters table. I see that's now fixed too. Having had my head bitten off for deleting an extraneous use of "meteor" elsewhere before, I wasn't going to touch it this time. -- 212.139.104.161 (talk) 23:20, 4 March 2013 (UTC)

Looks like the consensus supports "superbolide meteor". Previous Talk page consensus had agreed on that. Then, after it got changed, I proposed it in this Talk page section. That text was included in the wording μηδείς provided, and it would ensure "meteor" is in the first sentence. User:Abductive stated "not wedded to any particular text." 212.139.104.161 was okay with it, but wants the technically accurate "superbolide" included.
I will go ahead and change it in the article; now supported by two separate consensus discussions. Cheers. N2e (talk) 04:34, 6 March 2013 (UTC)
I'll repeat yet again that I was not talking about the lead but about the specific text "Chelyabinsk meteor superbolide" found here below the orbital parameters table. So now the lead has been altered multiple times yet again after people misread, or failed to read, what I wrote here. I give up. -- 212.139.104.161 (talk) 06:54, 6 March 2013 (UTC)
Hey 212, since on Wikipedia, anyone can edit, please just be bold and fix whatever you think needs fixed in the caption of some table. As long as it is consistent with the consensus on terminology we gained for the lede, I don't see any problem. Cheers. N2e (talk) 13:16, 6 March 2013 (UTC)
I had my head bitten off last week for deleting the word "meteor" when it appeared next to the word "superbolide". I wasn't going to touch this one. It was in the text below/after the table. It's since been fixed by others. -- 212.139.104.161 (talk) 13:30, 6 March 2013 (UTC)

Second paragraph

The second paragraph currently has poor grammar, poor punctuation and, in one case, a series of words that do not form a proper sentence. Some of the new information probably belongs in the article, not in the lead. -- 212.139.104.161 (talk) 12:33, 5 March 2013 (UTC)

Several people have since edited the text, without comment here. The point as to whether some of the "new" and more detailed information belongs in the article, rather than in the lead, has not been addressed. -- 212.139.104.161 (talk) 13:30, 6 March 2013 (UTC)

The total radiated energy of the fireball

The total radiated energy (90 kt) of the fireball refers to the optical emission of visible light only. From JPL's page - "The JPL fireballs website uses the following empirical formula derived by Peter Brown and colleagues to convert the optical radiant energy Eo into an estimate of the total impact energy E". JPL measure the brightness of the superbolide via satellite and use an empirical formula (E = 8.2508 x Eo0.885) to calculate the total impact energy, 440 kt (acoustic / explosion energy). The formula is based on the 2002 east Mediterranean event, that generated 26 kt explosion energy; See Fig. 1 in Brown et al. (2002).

Ref.: Brown et al., 2002. The flux of small near-Earth objects colliding with the Earth. Nature 420(6913), 294–296.

--Diamonddavej (talk) 22:05, 20 March 2013 (UTC)

For some reason calculating the given numbers with the equation and converting for kt doesn't give the same results. In any case, the original paper notes its optical energy equation relies on a number of assumptions (mean density, geometry, 6000 K Black body, etc.). By all means it's a close estimate at best. Mightyname (talk) 12:05, 26 March 2013 (UTC)

Artificial origin refuted off-hand?

The article does not explain the reasons why a non-natural origin for the event was immediately excluded. (I mean, for example some aldebaran greenlings, whose photon rocket journey ended badly). After all, nobody saw the thing, only the fireball that surrounded it, so how do we know if the inside of the fireball was a lump of stone or iron ore or a maybe saucer? 87.97.51.59 (talk) 20:29, 7 April 2013 (UTC)

If it hit the atmosphere like a meteor, produced infrasounds like a meteor, burnt up like a meteor and exploded like a meteor (leaving lots of little stoney meteorites on the ground), most meteorists will establish and record that it was actually a meteor because they had plenty of documented proof. If you want to say that Alderbarans were inside, or something like that, you first have to find a reference to a reliable source like a journal article. HarryZilber (talk) 03:09, 9 April 2013 (UTC)
Scientific proof would of been confirmed by analysis of the found samples and comparisons to other known meteorites. The recently added external link to the PBS NOVA documentary covers aspects of this and is worth a viewing. - Shiftchange (talk) 03:19, 9 April 2013 (UTC)
Until any Alderbarans contact us to find out what happened to their craft, we can only assume a natural origin from the data presented.--Auric talk 03:59, 9 April 2013 (UTC)
No quirky reply from the IP? The Alderans must have taken over Hungary. Where's Tom Cruise when you really need him? HarryZilber (talk) 14:28, 9 April 2013 (UTC)

What was the delay time in seconds between the observed flash and the arrival of the main blast wave?

Any references out there for the delay time? Or has anyone seen video footage taken from directly(or almost directly) below the hypocenter of the explosion were the delay between the flash and bang(like lightning and thunder) can quickly be determined?

This information would substantially add to the quality of the article.

By the way, although it doesn't meet wiki verifiability, but if anyone's interested the yield estimates are too high. Just check out the video five men at ground zero. Which was testing the AIR-2 Genie AA missile, exploded with a Yield of 1.7 kilotons and height ~6 km. That blast would have shattered windows below it too. So the meteor yield was probably no more than 100 kt, with my back of the envelop figures arriving at a figure of no more than 50 kt, and not 500kt as NASA has stated, that is 50 kt at the maximum height reported - 25km, and closer to 10 kt for a 15 km height of air burst.

Understandably I'm going against NASA with this one, but if memory serves the Russian's put the yield closer to 200 kt, right? http://www.youtube.com/watch?v=BlE1BdOAfVc

Boundarylayer (talk) 00:04, 4 March 2013 (UTC)

The main airburst was around 90kt, most of the kinetic energy was lost during atmospheric flight. -- Kheider (talk) 00:36, 4 March 2013 (UTC)
Delay time is rarely, and barely, under 90 seconds. Many of the videos show 2 to 3 minutes. A few show delay in excess of 6 minutes. It's all down to distance of course. -- 212.139.104.161 (talk) 01:08, 4 March 2013 (UTC)
This is one of the https://www.youtube.com/watch?v=odKjwrjIM-k videos close to directly below. -- 212.139.104.161 (talk) 01:13, 4 March 2013 (UTC)
Thank you for the speedy replies, wow great my method of calculating the yield was based on empirical data from nuclear weapons testing at comparable altitudes, and not the new method by NASA of basing it on fireball intensity(did they measure the fireball intensity from watching youtube videos or bhangmeters or something?) either way, but I'm glad I don't look like some fringe scientist now with my estimate being much closer to the updated official NASA number, I was totally aghast to hear it was being reported as 500 kt, I knew that was way off considering the reported height of burst 15-27 km. (1) But how and ever if NASA now put the explosion at an altitude of 23.3 km with a main explosive power of 90kt then should we not include these figures?
As for example, as the olive oil in your cupboard has more energy than TNT in units of Joules per kilogram see energy density, naturally total energy content tells you nothing about the power of an explosion, as TNT is more powerful than olive oil- i.e it can release its chemical energy faster, in a detonation event, so in units of the rate at which energy is released Watts per kilogram, TNT is more powerful.
What I'm trying to communicate with all this is that as Energy and Power are two related but separate physical units, an important distinction that sadly appears lost on countless editors and scientists alike, for example on the Black_Saturday_bushfires#Overall_statistics page it dubiously describes the output of energy from a forest fire as equivalent to 1500 hiroshima's... ;-|, How one can describe a slow burning forest fire as in any way shape or form comparable to a nuclear weapon detonation is beyond me. Similarly, equating total energy of a meteor superbolide event in units of power (kt) is also dubious(as the NASA guys kind of agree, if you get the feel of what they're saying after stating the total energy of the bolide event as 440 kt.) They're not happy about the dubious convention of doing so.
So in the interest of being informative, should we not discuss something along these lines in the lede? That the power of the main explosion was equivalent to 90 kt or almost 6 little boys which exploded over Hiroshima and the superbolide explosion occurred at 23.3 km in altitude? And maybe stating that the object had a kinetic energy of 440 kt in total but of this only a fraction of the total kinetic energy was converted into explosive power.
(2) That's some great work 212.139.104.161 thank you, can we put that ~90 second figure in the article? as all the article presently discusses is the delay time between the flash and the bang to get to Chelyabinsk, which is a city not directly underneath the explosion.
With the 90 second figure combined with the Speed_of_sound#Altitude_variation_and_implications_for_atmospheric_acoustics and the temperature of the ambient air on the day we can calculate the height of the explosion. This is likely how NASA arrived at their 23.3 km figure for the height of the main explosion.
Boundarylayer (talk) 11:47, 4 March 2013 (UTC)
Interesting meteor energy tables at Impact event. BatteryIncluded (talk) 14:14, 4 March 2013 (UTC)

Two small comments on the above: 1) the rough rule of thumb for sound is approximately one mile per second at standard temperature (again, rough rule). As kids we used to count seconds from a lightning flash until the arrival of the thunder to figure how many miles away the bolt was. A few of the YouTube videos showed or mentioned a figure of approx. 2:40, or 220 seconds between the flash and the sonic blasts, several of which arrived after the main pressure wave (on some videos you can hear up to eight). Given that sound is travelling much slower in the upper atmosphere, I'm thinking that the distance to the observers (without doing any of the math) was in the range of 160-180 miles from the blast, which is much greater than some of the figures I'm seeing above, which appears odd at first. However it makes more sense when you note that the blast did not occur above Chelyabinsk, but some distance offset from it.

2) A second thought is that researchers doing the calculations on the height of the meteor during the event may take advantage of the building shadows seen on multiple YouTube videos. Using some 3D and photogrammetric software, combined with the measured heights of the buildings/lampposts/objects in the videos, and the lengths and directions of their shadows on the ground, the software should be able to build a relatively good altitude/position profile of the meteor during its burst. Since there were multiple videos of the same same event showing many shadows, that should lessen the margin of error. The hard part for such an exercise would be to find and measure the exact heights of the buildings and lampposts which cast their shadows on the videos, and to exactly measure the lengths of those shadows on the ground. But for an accurate profile, everything there is doable, unlike Tunguska where the first scientists didn't arrive for almost 20 years. HarryZilber (talk) 20:19, 4 March 2013 (UTC)

"one mile per second" - no, it's more like 5 or 6 seconds per mile; 330 metres per second is an accepted figure.
2:40 is 160 seconds, not 220, which makes the distance about 50 to 60 km.
There's an article in the references that used the height of lampposts and length of their shadows to start calculating of the trajectory. -- 212.139.104.161 (talk) 10:27, 5 March 2013 (UTC)
Thanks for that; caffeine deprivation is a terrible affliction ;-) I obviously forgot the "divide by 5" part for the distance in miles. HarryZilber (talk) 16:59, 5 March 2013 (UTC)

Comment: This is an over-simplification of the travel time. Objects that are travelling faster than the speed of linear sound waves in the surrounding media (as noted above, that is roughly 0.2 statute miles / second at sea level pressure and yet slower at altitude where the air is more rarified), or explosions that meet certain requirements (e.g. detonation of high explosives) create shock waves, not linear sound waves. Note that shock waves travel faster than linear sound waves (no surprise there). The Chelyabinsk meteor generated shocks from both of these mechanisms, so estimating the travel time from a guess-timate of the altitude is not such a simple calculation. Wikipedia's page on Shock Waves discusses this to some degree, so I refer the sceptical there. Pretty cool stuff, this is certainly one of the more fascinating events in Physics in my lifetime. Segelflieger (talk) 06:57, 11 April 2013 (UTC)

Wrong time before impact

There is something wrong with the time from EUMESAT.

Improper Citation in Media Section

I tried to click the reference to The Atlantic article about how the news first broke in the US. The link isn't working, but also this should not be the citation for the statement from the Russian government. I can't find the statement from the Russian government that came out an hour after the event, but the article cited there is about the hockey blog Russian Machine Never Breaks which first broke the news in the US. Not sure how to make the section better, but I'm going to make a few edits and try. Feel free to discuss or change back. Just trying to fix it up a bit. Kaleidoscope-Eyes (talk) 17:09, 29 April 2013 (UTC)

Why is it important that a Hockey blog was the first to publish the news within the U.S.? Certainly it hit mainstream media within hours, so even if that blog published before anything else, does it really matter at this point? Tarl.Neustaedter (talk) 17:20, 29 April 2013 (UTC)
To me it's not really about whether it "matters" or not. And I agree, I don't think it really matters at this point. However, the source used in that section isn't correct and I couldn't find a source for the Russian PM's press release so I updated the sentence to fit the source because I couldn't do it the other way around. Sorry if I'm being unclear. Kaleidoscope-Eyes (talk) 17:33, 29 April 2013 (UTC)

"Coincidental asteroid approach"

The references under this heading are not valid, because all was published 15 February 2013, when we knew very little about the trajectory. For example, NASA believed that the meteor had a trajectory from north to south, when it in fact was almost straight from the east. — Preceding unsigned comment added by 176.70.245.240 (talk) 15:12, 18 May 2013 (UTC)

(Correcting the month in the text above.) I must add that you can't even use the picture from NASA (published 16 February), because it is propably the most inaccurate orbit model you can find. The best orbit model is probably one that use the calculation by Zulaga et al. http://arxiv.org/abs/1303.1796
It was known very early on that the trajectory of the impactor was significantly different than DA14. The NASA orbit diagram is more than sufficient to illustrate this. -- Kheider (talk) 16:30, 18 May 2013 (UTC)
Of course not; NASA didn't even know that the trajectory was from the east. And still, there is the need for better references in the section, and not only references from 15th February. — Preceding unsigned comment added by 176.70.245.240 (talk) 16:53, 18 May 2013 (UTC)

Asteroid --> superbolide meteor --> explosion --> light & radiant heat reach ground --> sound wave reaches ground

I have copyedited the first sentence of the lede to correctly reflect this order of the event. This is consistent with the outcome of several extensive Talk page discussions in early March working on the topic to gain consensus on the lede.

The order of the event was Space object/Asteroid --> entered Earth's atmoshere --> became superbolide meteor (aka fireball) --> explosion --> light & radiant heat reach ground --> sound wave reaches ground

I've put back in the sentence as it existed after that extensive consensus building effort, only without repeating all the sources in the lede section, as they are adequately sourced in the body of the article.

Additional copyediting can likely improve it further. But since it was the result of consensus, perhaps we could discuss a bit here on the Talk page first. Cheers. N2e (talk) 15:31, 5 May 2013 (UTC)

Hi N2e, good work, however the phrasing "...a small asteroid entered Earth's atmosphere" may be a bit misleading, since, as I understand, an asteroid is now defined as an object over 1 meter in size, whereas the CM is estimated at approximately 20-23 m by the latest estimates. Would not something like "...an approximately 20 m wide asteroid entered Earth's atmosphere..." be less ambiguous? 'Small' could mean 2 m or 200 m, depending on context. Best: HarryZilber (talk) 16:20, 5 May 2013 (UTC)
Yeah, point taken. I just took the text that existed in the lede on c. 8 Apr 2013, prior to the copyedit of the lede on or about 9 Apr 2013. Take a look at that history, it had about three or six sources, and we could see if there is a clear consensus on "small." I have no particular dog in the fight, just trying to get the lede representing reality.
That being said, since asteroids start (smallest) at size about 1 m, and go up in size to 10's or 100's of kilometres, I think I could at least entertain the possibility that the astrophysics/planetary science community could quite easily consider the <20m asteroid over Chelybinsk a "small" one. I'll try to look at those sources in the next few days to see if there is some sort of a broadly accepted scale on these things. Cheers. N2e (talk) 19:04, 5 May 2013 (UTC)
I think that replacing the "small" characterization with the actual size would be good. Information is better than characterizations, doubly so when the characterization is arguable such as this one is. North8000 (talk) 19:21, 5 May 2013 (UTC)

Tyson comments reinstated as entirely pertinent and accurately cited / Says nothing

Abductive, your distaste for the U.S. astrophysicist Neil deGrasse Tyson is readily apparent where you wrote in your edit summary "Tyson gets enough publicity, so his saying nothing new here is REMOVED" when you deleted his statements on the reason the Chelyabinsk meteor impacted the Earth's atmosphere without warning. That material is entirely appropriate to the article and your deletion of valid material makes the article less informative, not better. Your feelings about Tyson are apparently affecting your judgement so, sorry, your inappropriate deletion is being reverted again. HarryZilber (talk) 12:48, 5 May 2013 (UTC)

Again Abjuctive, deleting the name and organization of a scientist you may not agree with is not helping the article. In the section on media coverage on the event, including the scientist's name is appropriate and adds credibility to his statements, which were not, by the way, stated anywhere else on the page contrary to your edit summary. HarryZilber (talk) 20:01, 7 May 2013 (UTC)

Neil deGrasse Tyson does not need further publicity. His NON-STATEMENT on how nothing was tracked and two unrelated events are related (or unrelated--it's unclear) does not belong in this article. Wikipedia article report scientific consensus, not the opinions of individual camera-lovers. It is important to note that peer-reviewed secondary sources are not interested in Tyson's opinion (seeWP:PSTS). As such, there are only the following options:

  1. Tyson's view represents the scientific consensus, in which case Wikipedia should not report the idea as his alone.
  2. Tyson's view is not consensus, in which case it should not to be reported in this article.
  3. Tyson is completely wrong (or wrong-headed), in which case his opinion does not belong in the article.
Frankly, I think the article is stronger for a noted NYC Planetarium Director's quote. I'd like to see more of what he said on this topic to be put into the article, instead of delete all mention of it. I don't think scientific consensus has been fully established, and even if it has, his could be a minority view. Therefore, I would like to say none of your options fit the case, and I don't share your concerns about "publicity." There is no doubt the article would be improved by more material, in my view. Jusdafax 20:53, 7 May 2013 (UTC)
Planetarium Director = NOT AN EXPERT. Abductive (reasoning) 00:46, 8 May 2013 (UTC)
Well the article might or might not be stronger with a range of views from different professors, and planetarium directors, NASA employees, etc. Heck it might (or might not) be stronger with a range of opinions from US, and Russian, and French, and Japanese experts on the matter. But if so, that would then go in a section describing a range of opinions from some cross-section of folks who might have something to say about the matter. We don't have that in the article now, so tying one particular persons name to an opinion this is both widely shared and the broad consensus of a large number of near-Earth object experts is not helpful to the article. Just because Tyson is a media-guy who is telegenic and therefore frequently used by broadcast media is no reason to elevate his opinion, or state that this is his opinion, above many other equally deserving experts who have weighed in on the subject.
I say, leave the content claim in the article, but leave off the personality of who said it. Who said it is not terribly relevant to the Chelyabinsk Meteor. Cheers. N2e (talk) 02:31, 8 May 2013 (UTC)
Just what was said: "New York City planetarium director Neil deGrasse Tyson stated the Chelyabinsk meteor was unpredicted because no attempt had been made to find and catalogue every 15-metre near-Earth object.[77] In television media interviews shortly afterwards Tyson also noted the disturbing closeness of the two completely unrelated events." Neither facts appear elsewhere in the article, i.e.: no agency has attempted to survey 15 meter objects and that the close proximity of the two asteroids (rated at a one in a hundred million chance event) was disturbing. In Wikipedia, an article's important facts should always be attributed and statements of great importance are frequently attributed within its text to those who made them. The scientist adds gravitas to the importance of this article and is he is eminently qualified to be attributed with the article's text. Besides being a "planetarium director" Tyson is an astrophysicist and science writer, so sorry Abductive, he is an expert, despite your opinion. He is also not the only person named in the article. HarryZilber (talk) 04:13, 8 May 2013 (UTC)

"Including 311 children"

This isn't CNN. There's no reason to specifically go "oh, and a bunch of children were injured" unless you're catering to people's emotions. It's unnecessary to give them special mention unless you list the injuries for men and women too. RocketLauncher2 (talk) 14:39, 13 June 2013 (UTC)

I agree, there is no need for the special mention of children. (To make a point:) What other special groups should we give attention to? CombatWombat42 (talk) 16:36, 13 June 2013 (UTC)
I disagree. This is an encyclopedia, which preserves knowledge. Why not break out how many children were injured? If there are reliable sources that would break out how many of the injured were men vs. women this would be good to include, but I don't see why not include number of children just because the number of men and women injured is not known. Victor Victoria (talk) 17:47, 13 June 2013 (UTC)
It's more that the reason it's there is because people consider children especially important. If there were other statistics then it'd be fine, if children injuries are the only one known then it should at least say "men and women injuries unknown" or something along those lines, else it seems like the number of injured children is included just to appeal to the human weakness for children. RocketLauncher2 (talk) 23:06, 15 June 2013 (UTC)

Victor Victoria is correct. Since the figure was mentioned in a number of articles and is properly cited then its pertinent to the article and valid to include here. Actually, the material is more than useful as it also points to society's concern with its more vulnerable citizens. WP:NPOV certainly does not contain prohibitions against reporting child casualties as was indicated on the edit summary which removed it, and the information is valid material which was improperly deleted. As for the argument of non-child injuries being unreported that's disingenuous, as that figure is available to anyone with a bit of math (1,491-311=1,180). The deleted info is now being reinstated. HarryZilber (talk) 14:07, 13 July 2013 (UTC)

It's undue weight. There's nothing special about this event that would have targeted any specific subgroup (women, children, etc.) that needs to call it out. Calling out the # of children, even if it is IDd by a number of sources, is a kin of the cry "won't someone think of the children?!" It's an unnecessasry, purposely skewing stat. --MASEM (t) 14:43, 13 July 2013 (UTC)
Hi Masem, I disagree with that. The information, comprised of three words, hardly qualifies as undue weight when the total number of casualties is mentioned three times within the article (we can add in the 1,180 figure as well). Many other articles quote the number of child casualties, probably on the premise that society as a whole has a special concern for them –something I can see nothing wrong with. HarryZilber (talk) 15:03, 13 July 2013 (UTC)
First off, they're not causalities - simply those injured from the damage from the shock wave. There are cases - typically when we're talking wars with civilian casualties or something that was specifically targeting school-aged children (like the Sandy Hook shooting) when it is reasonable to understand the account of number of women/children/other groups injured or killed. But this event is "indiscriminate" in that anyone in that area was potentially at risk from the damage of the shock wave, and thus there's no reason to expect children to have been more at risk, nor a problem of ethics of children being targetted. Including that number is basically trying to plea to basic human senses with no reason. For example, Hurricane Katrina doesn't make a difference between children and other groups, since a natural disaster is not prone to impact one group over another. --MASEM (t) 15:10, 13 July 2013 (UTC)
Sorry, but other articles, such as the one on the Titanic quote child casualties in detail. Again, imho, there is nothing sentimental, unseemly or contrary to Wikipedia's NPOV policy in noting the number of child injuries when that information is available. A part of the same section also discusses the 20 children injured at a school, so informing readers of the total number of children treated adds context. HarryZilber (talk) 18:11, 13 July 2013 (UTC)

Use of {convert} template?

My attention was drawn to the display of the speed of the meteor when a recent editor added the speed in km/h. It seems appropriate to use the {Convert} template, but I don't know how to use it with more than two units, one "input" (in this case, km/s) and more than one "output" (mph & km/h). TomS TDotO (talk) 11:33, 1 August 2013 (UTC)

Does the {{convert}} page help? The last few examples (using |ha sqmi| in the "single value" table show how to display multiple results. -- 212.139.104.181 (talk) 20:16, 1 August 2013 (UTC)

Delay between visual appearance of meteor and shockwave

One of the aspects of this event I found the most interesting was the long delay between the visual meteor and the arrival of the consequent shockwave (88 seconds in one report). In hindsight this makes sense given the altitude and the speed of sound, but it surprised the heck out of the onlookers and perhaps increased the number of injuries due to people gawking out of soon-to-be-shattered windows.

The article currently says little or nothing about this aspect: it would be great to add it. -- Dan Griscom (talk) 17:26, 1 July 2013 (UTC)

88 seconds seems to be about the quickest anyone has reported. Some other places, those a bit further away, mentioned that the sound arrived some 4 - 5 - 6 - 7 minutes, or more, after the visual event (though it was not nearly as loud by then).
In many of the recordings taken close to the main damage areas, the sound rumbles on for at least 2 or 3 minutes. The initial sound was heard from the closest point of the track. However, since the track was some 200km long, the sound from further back along the track took much longer to arrive.
Every recording has people shouting, music playing or car alarms sounding. Many recordings cut off before the sound has completely died out. A clear recording of the whole event would likely yield some useful data. -- 212.139.104.181 (talk) 20:27, 1 August 2013 (UTC)

Weight of the Eiffel tower

In several places the mass of the meteor is compared against that of the Eiffel tower, which is referenced at 11000 tons. However, I suspect (being a French reference) this means 11000 metric tonnes - this seems to be confirmed by other sites on the internet. The official Eiffel tower site (in French) gives the weight as 10100 metric tonnes (= 11 133 short tons): . This would make the Eiffel tower greater than the estimated meteor mass. HYanWong (talk) 19:51, 20 June 2013 (UTC)

I think this is a dumb comparison anyway, no one has any real concept of what the eiffel tower weighs. They know it's big and made of iron, but so was the meteor. CombatWombat42 (talk) 20:23, 20 June 2013 (UTC)
They knowing how big it is and what it's made of is precisely why it's a good comparison I think. I think it should be used, but maybe a little less often. RocketLauncher2 (talk) 20:48, 20 June 2013 (UTC)
Regardless of how sensible it is, if the comparison is used, it should be used correctly. The masses are vaguely the same for what it's worth. Certainly the estimated meteor mass is not strictly greater than the Eiffel tower, so the page should be changed. Usually the weight of the tower is stated to show how light it is in comparison to its size. So it's not a good example to use to give people an impression of size etc. HYanWong (talk) 12:55, 21 June 2013 (UTC)
Two times: Correct - What about 60 (or so) electric locomotives? Or 3 (?) very heavy goods trains?--Helium4 (talk) 05:01, 26 August 2013 (UTC).
Agreed. The point made above is right on target - Usually the weight of the tower is stated to show how light it is in comparison to its size. So it's not a good example to use to give people an impression of size etc. The comparison with the Eiffel tower should be removed.

Velocity contributions

The velocity or trajectory of the meteor ist the vector sum of 1. the meteors movement against the sun (plus direction to fixed stars) + 2. movement of earth on its path along the ecliptic + 3. local movement of the earths surface by turning (eastwards) + 4. (rather neglegible:) winds.

Roughly 3. contributed about 1 % to the velocity. Component 2 needs an astronomers skill. — Preceding unsigned comment added by Helium4 (talkcontribs) 05:13, 26 August 2013 (UTC)

There's two velocities that can be quoted:
  • The actual velocity through the Solar System, i.e. relative to the Sun.
  • The velocity relative to the Earth's surface.
As you mention, the latter is fairly complicated to compute. -- 79.67.249.118 (talk) 21:41, 11 September 2013 (UTC)

Suggest remove the word "fortunately"

From the following line: "the atmosphere fortunately absorbed most of the explosion's energy". Maybe not fortunately to scientists interested in such events, although fortunately to damage and human life. — Preceding unsigned comment added by Eyeskies (talkcontribs) 20:25, 27 July 2013 (UTC)

Seriously? The latter is far more important than the former.Blaylockjam10 (talk) 08:29, 2 November 2013 (UTC)