Last night I went to bed pleased with the evening's LiveChat with meteor specialist Bill Cooke from Marshall Space Flight Center in Alabama. I asked him to come on and chat about the close flyby of asteroid 2012 DA14 later today. It was a great time having Mr. Cooke come back to to share with our community again. Little did either of us know we would wake up to this:
A multi-ton meteoroid (or small asteroid) entered the atmosphere at 37, 000 MPH producing what astronomers would refer to as a day-time bolide. You can do an internet search and find many examples of these bolides, but this was a big one. In the dash-cam video above you can see the body beginning to incandesce as it reaches an increasingly denser atmosphere, finally reaching a point where it can no longer compress the gasses in front of it creating an explosion. You would expect an explosion that large would produce a pretty large bang, but that fireball is a little farther away than it is perceived. Our mind pictures it like a jetliner, a few miles high and ten or so miles away. But this is much higher and farther, meaning the sound takes longer to travel.
As you can see, the smoke trail has had a couple minutes to expand before the shock wave (essentially a sonic boom combined with the explosion) hits, trailed by smaller pops probably caused by the breakup of the asteroid. It is reported that a crater has been discovered, but no reports of the meteor or fragments striking anyone. Many hundreds have been injured by the effect of the shockwave, mostly from falling glass and plaster.
Such a fireball could happen anyplace, anytime. I have seen one daytime bolide and many at night, though none this large. Keep your eyes open and one day you may be witness to such an event!
Next week, we welcome back Dr. Frank Summers to share the latest and greatest images from the Hubble Space Telescope. Don't miss it, or the INSPIRE Cafe that precedes it, next Thursday at 8pm CT!
Discuss this blog here: http://tinyurl.com/bloginspire12
No comments:
Post a Comment