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Duck! Meteor! Oh, Maybe Don't Bother - This Time... 49
RockDoctor (Slashdot reader #15,477) is a professional geologist, and asks: Did anyone feel a sudden wind through their hair at about 17:19+00:00 on Monday, particularly in the mid Pacific? No?
Good. Nobody else did. Nobody noticed the asteroid whizzing past just above the Earth's atmosphere (for certain values of "above" including "not very far" and "373km above ground"). That's the closest natural body (i.e., not a spacecraft) documented in near-Earth space which hasn't actually hit the thick-enough parts of the atmosphere to glow, fragment, make sonic booms and dent automobiles.
So, we dodged another bullet, and no windows were broken. This one probably wouldn't have done significant damage even if it had touched down in fire and fury — it was about half the size of the 2013 Chelyabinsk meteor, and so around one eighth of the energy (and potential damage). Everyone can go back to bed and sleep easy. Right?
But one tiny thing to disturb your sleep : we didn't see this one coming until after it had gone past us. Nor did we see it in it's close approaches on 2014-10-26.60152 or 2017-11-06.57008. And with another 39 projected Earth approaches before the next turn-of-century, it's pretty obvious that one day this is going to hit us.
For those who know what an MPEC is [a Minor Planet Electronic Circular], Bill Grey has written up one of his "pseudo-MPECs" with links to other work on this object here, while the actual discovery record is here. The object has been given a formal name of 2020 VT4 unless the discoverers at the ATLAS Mauna Loa Observatory choose to give it a name ("COVID", or "hair-parter", or "hats-off", perhaps. Or just "Rupert".)
Wikipedia has caught up too.
There will be another close-pass, and an impact, one day. This doesn't change the odds of that happening (probability 1), but it might make it feel a little more immediate.
Good. Nobody else did. Nobody noticed the asteroid whizzing past just above the Earth's atmosphere (for certain values of "above" including "not very far" and "373km above ground"). That's the closest natural body (i.e., not a spacecraft) documented in near-Earth space which hasn't actually hit the thick-enough parts of the atmosphere to glow, fragment, make sonic booms and dent automobiles.
So, we dodged another bullet, and no windows were broken. This one probably wouldn't have done significant damage even if it had touched down in fire and fury — it was about half the size of the 2013 Chelyabinsk meteor, and so around one eighth of the energy (and potential damage). Everyone can go back to bed and sleep easy. Right?
But one tiny thing to disturb your sleep : we didn't see this one coming until after it had gone past us. Nor did we see it in it's close approaches on 2014-10-26.60152 or 2017-11-06.57008. And with another 39 projected Earth approaches before the next turn-of-century, it's pretty obvious that one day this is going to hit us.
For those who know what an MPEC is [a Minor Planet Electronic Circular], Bill Grey has written up one of his "pseudo-MPECs" with links to other work on this object here, while the actual discovery record is here. The object has been given a formal name of 2020 VT4 unless the discoverers at the ATLAS Mauna Loa Observatory choose to give it a name ("COVID", or "hair-parter", or "hats-off", perhaps. Or just "Rupert".)
Wikipedia has caught up too.
There will be another close-pass, and an impact, one day. This doesn't change the odds of that happening (probability 1), but it might make it feel a little more immediate.
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unlikely it would hit anything else. Space is big, you won't believe just how vastly, hugely... Doesn't matter, these below 25 meter diameter rocks are of no concern. No reason to try to even track them.
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Unless you happen to be in the city underneath one when it decides to do it's thing [youtu.be]
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There is no mechanism to generate such a rock, we've only ever detected nuclei and positrons moving at speeds like that and above from space.
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We'd certainly notice if anything like that ever hit the atmosphere of any planet or even the Sun's photosphere or any asteroid.
Supernova shoot hot gas that can be up to 10% C, the dust and rocks form later when clouds cool and coalesce.
http://www.spaceref.com/news/v... [spaceref.com].
Dodged for Now (Score:5, Insightful)
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>Hard to imagine it being worse.
trump still being around?
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Frashokereti is happening after all? Well what do you know.
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I don't read the mailing list every day, looking for news of impending Aves-killers. But I try not to get more than 3 days out of date. Still 29 days to go!
5 to 10 meters diameter - not a concern (Score:1)
This thing was incapable of reaching the ground even if there was collision, not valid to say this is a warning or reason for concern
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Re:5 to 10 meters diameter - not a concern (Score:5, Insightful)
That's a bit silly though. We didn't see it because it was small. Because it is small, it isn't all that important that we see it.
Nobody cares if they don't see the ladybug about to collide with them as long as they DO see the city bus heading in their direction.
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At that size, it's not going to crash anywhere, it will burn up. It could cause a few broken windows, but not as many as the one over Russia a few years ago.
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Is the size where we will see it coming a city-killer, or just a pretty light in the sky though?
We should be keeping a weather eye out for big rocks, in my view.
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That "weather eye" is what saw this one. As it left the scene.
Re:5 to 10 meters diameter - not a concern (Score:4, Insightful)
"This thing was incapable of reaching the ground even if there was collision"
Tunguska didn't hit the ground either, but the explosion in the atmosphere did take out a lot of trees...
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not relevant, Tunguska meteor was between 100 and 200 meters, but this article's little chicken-shit rock is too tiny to cause harm no matter what or where it will hit. It can do nothing.
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Depends on what it's made of, how dense it is, how solid it is. A 5 meter nickle-iron meteor would almost certainly ruin your day.
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The Chelyabinsk meteor was an extremely bright, exploding fireball, known as superbolide, measuring about 17 to 20 m (56 to 66 ft) across, with an estimated initial mass of 11,000 tonnes, as the relatively small asteroid entered Earth's atmosphere. Notable Meteors [wikipedia.org]
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https://en.wikipedia.org/wiki/... [wikipedia.org]
The meteorite has been classified as an LL5 ordinary chondrite. First estimates of its composition indicate about 10% of meteoric iron, as well as olivine and sulfides.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Although they are fairly rare compared to the stony meteorites, comprising only about 5.7% of witnessed falls, iron meteorites have historically been heavily over-represented in meteorite collections.[3] This is due to several factors: ...
They are much mor
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If it had come in at a slightly different angle, or survived a few more seconds coming through the atmosphere, that meteor might have wiped Chelybinsk off the map.
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No Guarantee to hit us... (Score:2)
It has close passes with Venus. Going out to 2200 has no impacts with either body.
But I doubt it will hit both Venus and Earth!
it's pretty obvious... (Score:2)
" it's pretty obvious that one day this is going to hit us."
Is it? Maybe I'm just dumb, but I don't see how this is obvious. Can someone explain?
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Yeah, I'm not following the hand-waving argument either.
So just to be argumentative... (Score:4, Informative)
"But one tiny thing to disturb your sleep : we didn't see this one coming until after it had gone past us."
Why should we care that an object this small was not seen until it was past us? The submitter already noted an impact from this object would not have any significant effect.
The implicit assumption appears to be that "since we missed this small one, we are missing bigger important ones"... but if that's what he's trying to say, he should offer at least a modicum of support.
"There will be another close-pass, and an impact, one day. This doesn't change the odds of that happening (probability 1), but it might make it feel a little more immediate."
Again, the submitter offers no supporting evidence for this at all. If it's true, then provide some proof.
FWIW the risk assessment on the linked European Space Agency page states:
"Object is not in risk list
Object is not in priority list"
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Why should we care that an object this small was not seen until it was past us? The submitter already noted an impact from this object would not have any significant effect.
Probably because small thing that's really, really close is as visible, or even more visible as a big thing that's further away. If you can't see a toy truck that's 5 cm from your eyeball, do you feel confident stepping out into the street, even after you've looked both ways? It really does raise all kinds of questions about what we can actually spot and whether we can spot it in time for it to make any difference. The concerns could be quite easily explained away of course, with an explanation of precisely
Detection distance varies with object size (Score:4, Interesting)
Missing small stuff isn't itself concerning. The question is whether this changes our estimates of our ability to detect dangerous asteroids at larger distances.
There is some overall risk vs size to consider- presumably a Cretaceous sized impact would kill billions (maybe make humans extinct) but is a few x 100M year scale event. More common smaller bodies could still kill millions. There is some range of sizes and advanced warning that would make a deflection mission possible.
You insensitive clod! (Score:1)
I don't have any hair.
Who cares about total destruction? (Score:1)
Comment removed (Score:5, Informative)
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That one bothered me as well, but it's par for the course for this sort of thing. Think back to _Armageddon_ with its asteroid "the size of Texas". So, in this case, It seemed like they mean half the diameter, so about an eighth of the actual size. I think a lot of us read that, shook our heads a little, but then just moved on. We're just too used to it.
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Not only that..
[Chelyabinsk ] had "... a total kinetic energy before atmospheric impact estimated from infrasound and seismic measurements to be equivalent to the blast yield of 400â"500 kilotons of TNT (about 1.4â"1.8 PJ) range â" 26 to 33 times as much energy as that released from the atomic bomb detonated at Hiroshima.[9]"
1/8 of 26 is still over 3x Hiroshima.
I fail to see a 3x Hiroshima blast occurring randomly somewhere on earth being "nothing to worry about".
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Title is unclear (Score:1)
So did it turn out to be a duck, or a meteor? From the size, I'm thinking meteor. /Also, Rabbit Season!
And with the Arecibo radio telescope going to be d (Score:1)
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Indeed. Areceibo was one of only two systems in the world regularly doing active radar astronomy [wikipedia.org], which is needed for precise long-term orbit determination for near Earth asteroids, as well as imaging. With than gone, only Goldstone [wikipedia.org] is left. I don't see 2020 VT4 on the list of upcoming obervations [nasa.gov], but maybe it will be added (or maybe it's too small).
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I too would welcome a decent fresh astrobleme as a treat.