Update, March 31: The confusion over whether the March 29th Virginia fireball was a meteor or a Russian rocket re-entry has been resolved — in favor of a meteor.
On Monday Geoff Chester of the U.S. Naval Observatory said he was quite sure that the brilliant, booming fireball was the re-entry of the spent Russian Soyuz rocket that recently carried crew members to the International Space Station. See the story about Chester's claim on Space.com. It was picked up by much of the media.
However, Baltimore Sun reporter Frank Roylance weighed in, quoting satellite tracker Ted Molczan:
"The U.S. Strategic Command's final report on this [rocket] decay predicted decay over 24° N, 125° E, [near Taiwan] on Mar 30, within 1 minute of 03:57 UTC (11:57 PM EDT).
"It did pass within sight of Virginia and Maryland Sunday night, but at about 9:26 PM EDT, about 2.5 hours before decay. It was 137 km high, but that is far too high to have begun burning. Burning begins a little below 100 km. The object was in Earth's shadow, so it was invisible, because it was not burning yet."
Moreover, the fireball reportedly lasted only about 5 to 8 seconds. Re-entering satellites move more slowly, last much longer, and generally cross the whole sky.
Then the final word came Tuesday morning from the Joint Space Operations Center at Vandenberg Air Force Base:
"The JSpOC tracks over 19,000 manmade objects in space. The 'bright light' that was reported on the East Coast on Sunday, 29 March at 9:45 p.m. EST was not a result of any trackable manmade object on reentry."
So the hunt for fallen meteorites (likely near the southeastern Virginia coast) is back on. Or maybe should be. Here's our original post about the big boomer:
Bright fireballs — really brilliant meteors, the kind that flood police stations with phone calls — aren't all that rare. Anyone who spends a lot of time under clear night skies will probably see a real screamer once or twice in a lifetime. Fireball descriptions are routine on the meteorobs mailing list of active meteor observers, and the American Meteor Society already has a big list of fireball reports so far in 2009.
But the one last night (Sunday evening, March 29, 2009) was unusual even by fireball standards. So far we've heard of sightings from Maryland to North Carolina. This is from longtime astronomer Kent Blackwell in Virginia Beach, Virginia:
"At precisely 9:40 p.m. EDT, Mark Ost and I were observing the night sky with our telescopes. Suddenly the ground lit up a bright green color. Gazing skyward we saw what appeared to be brilliant fireball meteor. As it moved across the sky NNE between Ursa Minor and Ursa Major it turned from a green color to a brilliant orange, with a white core. Two and a half minutes later we heard a low-pitched rumbling sound.
"I've been observing more than 40 years but have never seen a meteor this bright. It was absolutely spectacular!"
Similar stories are flooding the internet; for instance here. (And here are more and better reports.) Some of officialdom got scared: "Emergency crews fanned out across the city looking for whatever caused a loud explosion Sunday night," said WVEC-TV in Virginia Beach.
Meteor specialists perk up especially at reports of rumbling or booming in the minute or two after a fireball. If a meteoroid penetrates deep enough into the atmosphere that sounds can reach the ground (as opposed to being refracted upward), it's a sign that the meteoroid survived low enough that it likely dropped fragments on the ground. Dozens or hundreds of fragments from about the size of a golf ball to a softball are likely to be awaiting discovery in a strewnfield many miles long and a few miles wide.
If at least two observers far apart determine the meteor's accurate path with respect to the stars (or, less optimally, with respect to landmarks on the ground), then it's possible to reconstruct the meteor's actual three-dimensional path through the atmosphere. This tells where the strewnfield should be. Extrapolating back in the other direction, it also tells something about the object's orbit in space before it encountered Earth.
And if you caught a picture, please post it with us! We've seen none yet (the icon with this article is an old Leonid fireball from years ago.)