That is an amazing event. I am not sure I buy the meteorite story. Has anyone checked on 2012-DA14 [1] the asteroid that was supposed to cross between the earth and geosync orbit this evening? One conjecture would be it knocked something out of orbit.
The air defense stuff is somewhat hard to believe, we don't intercept de-orbiting space junk, much less less hypersonic meteors. Further every missile interceptor that is publicly disclosed (which includes the US attempts at an exo-atmospheric interceptor) have boost stages that generate a lot of vapor, there is no rising vapor trail in any of the videos of a ground based interceptor.
Finally there is the magnitude of the flash. Given the lack of sparkles on the video I don't believe what ever exploded was nuclear but on the videos with timers watching the flash and timing the 'boom' correlates with the 20 - 25 km (80,000') in altitude. One hopes it wasn't a surveillance aircraft that was destroyed. I'm sure if it was we'll hear about that in the morning.
An asteroid the size of 2012-DA14 would hit with a force of nearly 3 megatons. This meteor, and it is enormously consistent with a meteor and nothing else, would likely only be around the size of a car or so, over a hundred times smaller in each dimension (and over 10,000x dimmer and harder to detect via telescope) than 2012-DA14.
Not to be a pill if you read closely I said "something it knocked out of orbit" not it. Because yes, if it had decided to hit the planet we'd be glued to CNN or something right now.
One of the interesting things to me is the 'herd' phenomena that comes about because of gravity creating clumps of things which, when they collide with something else become a sort of herd moving in a similar direction. Comet tails, and wandering asteroids, rarely do things fly through space it seems without some sort of companion material flying along with them.
Not the case here according to sources who say it had a different orbit than 2014-DA14 but it was something I was wondering about. Has anyone found a USAF Space Command radar track yet?
I don't think we have anything in orbit that would burn that bright, certainly not for that long.
In orbit satellites are relatively slow (10 km/s-ish) and light (10 tons is a lot. The ISS is way heavier, but too flimsy to make it down in one piece)
Speed, in particular, counts, as kinetic energy goes with the square of speed. At 70km/s (IIRC, the top speed a meteorite is expected to have relative to earth), a kg of meteorite has as much kinetic energy as 50-ish kg of in orbit mass.
I think it's a really bad idea to start using Twitter followers as a credential. That being said Phil Plait is a legit astronomer and has a Ph.D in Astronomy and worked on the Hubble Telescope and has done a TED talk on defending Earth from asteroids. With real credentials like those you're doing a disservice to first mention the number of Twitter followers to validate his expertise.
I'm pretty sure mentioning the amount of twitter followers he has as credentials was a joke, but I agree with your point. I don't think anyone would contend the fact that Ashton Kutcher had the final say in all matters.
The general idea being that the Earth moves ~100,000km/hr around the sun, and with the asteroid fly-by many hours away, that would mean a pretty wide orbital gap.
In the various videos, there are a few noteworthy artefacts.
1) After the bright white flash, we see debris flying in the opposite direction to the meteor's path, in a parabolic trajectory - i.e. falling.
2) Your AMM system doesn't need to be hypersonic to intercept a hypersonic target. The key here is "intercept". You launch a missile to be where the target is going to be, in a direction >90deg away from the target's path.
3) The Russian AMM system that would be used in these circumstances would be the 53T6 Gazelle, which is equipped with a 10kt warhead.
I'm inclined to give the air defence line credence.
I've never witnessed a nuclear explosion first-hand, but that seems like a mighty small flash for a nuclear explosion.
Edit: Also, why don't we hear any EMP effects on the radio signal in http://www.youtube.com/watch?v=tJOJ6B2XOyA ? If anything, the audio gets clearer right at the point you seem to be claiming is a nuclear detonation.
* It only shows when the meteor is close to the center of the lens.
* You can see reflections of two lens elements, one is smaller and brighter than the other. The smaller one is the element closer to the imaging sensor, and moves in parallax to the other one.
Actually, in that video, you're right, that's lens flare. Still, the superheated trail suggests that something very intense happened at that moment. It could have been the meteor breaking up, but that kind of "burning air" phenomenon is also associated with nuclear detonations.
The air defense stuff is somewhat hard to believe, we don't intercept de-orbiting space junk, much less less hypersonic meteors. Further every missile interceptor that is publicly disclosed (which includes the US attempts at an exo-atmospheric interceptor) have boost stages that generate a lot of vapor, there is no rising vapor trail in any of the videos of a ground based interceptor.
Finally there is the magnitude of the flash. Given the lack of sparkles on the video I don't believe what ever exploded was nuclear but on the videos with timers watching the flash and timing the 'boom' correlates with the 20 - 25 km (80,000') in altitude. One hopes it wasn't a surveillance aircraft that was destroyed. I'm sure if it was we'll hear about that in the morning.
Definitely a mystery.
[1] http://www.guardian.co.uk/science/across-the-universe/2013/f...