[meteorite-list] Russian meteorite event

From: Bruce Wegmann <brucewegmann_at_meteoritecentral.com>
Date: Fri, 15 Feb 2013 11:53:38 -0800
Message-ID: <CAEvfSu57Od3hxjR9+BMKG9W8e+sP4rMaDWzxZhcV8-15NC2Tuw_at_mail.gmail.com>

  A remarkable co-incidence that this fell within a couple days of the
anniversary of the Sikhote-Alin fall (with which it will doubtless be
compared), and during the nearest-ever approach of a significant-sized
asteroid. In the videos I have seen, the terminal flare of this looks
comparable to that of a nuclear detonation; in one the fireball passes
nearly directly overhead, and the ambient light intensity is
blinding...the fears the ancients had of such events is starting to
look more reasonable. The news coming out of this area in next few
days should be intensely interesting. There is one video of the smoke
trail, showing the unusual parallel trails; about 30 seconds in, he
catches the shock wave. It's probably the best record of the actual
acoustic phenomina we'll get...the initial thunder-like blast,
followed by a long series of crackling and popping; Nininger mentions
such descriptions in Find a Falling Star...now we can hear it for
ourselves...remarkable!
  I keep hearing the estimated weight of this at 10 tons or
so...that's laughable! If this was about the size of a bus, and
composed of ordinary chondritic rock, the mass would be something on
the order of 270 tons, achondrite, 220 tons, nickel-iron, 800 tons.
There's probably more than a couple hundred tons of pulverized
material in just the smoke trail; compare it to the drawing of the
Sikhote-Alin fall...the resemblance is more than a passing one. In
particular, there is virtually no fragmentation during the
incandescent portion of the flight, in stark contrast to, say, the
fall of the Peekskill bolide. The S-A iron broke up just few miles
above the Earth's surface; I'm guessing something similar may have
happened here, and the amount of recoverable material of comparable
mass.
   I'm hoping for another planetary, too, but my money is that we're
looking at another iron fall. My guess is that we'll know for sure in
the next 48 hours, maybe less.
Received on Fri 15 Feb 2013 02:53:38 PM PST