[meteorite-list] Boom 28 secs after Russian meteor passes overhead

From: Rob Matson <mojave_meteorites_at_meteoritecentral.com>
Date: Sat, 16 Feb 2013 17:15:08 -0800
Message-ID: <001301ce0cac$39d06530$ad712f90$_at_cox.net>

Great find, Robin. (Though I nearly could bear to listen to that "music"!) One could
probably get a pretty good estimate of the average speed of sound below 10 km
altitude with a typical temperature profile for this part of Russia in early morning in
mid-February (presumably quite cold!) At, say, 310 m/sec, the bolide range is
only 8.7 km, so given the high maximum elevation angle of the meteor as seen
in the video, the altitude will only be a smidge lower than this. (This is VERY low,
which explains the severity of the shock waves.) --Rob

-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Robin Whittle
Sent: Saturday, February 16, 2013 4:53 PM
To: METEORITE LIST
Subject: [meteorite-list] Boom 28 secs after Russian meteor passes overhead

Here is a relatively little-watched video showing a 28 second time delay
after the meteor passes almost overhead, and slightly to the south:

  http://www.youtube.com/watch?v=odKjwrjIM-k

I am not sure where this is located. With some work such as that of:


http://ogleearth.com/2013/02/reconstructing-the-chelyabinsk-meteors-path-with-google-earth-youtube-and-high-school-math/

it should be possible to calculate its rate of angular movement. There
is a ~28 second time delay between the meteor passing almost exactly
overhead, which with a little work could be refined to a figure accurate
to a fraction of a second. According to a post at the abovementioned
page, the well known video:

  http://www.youtube.com/watch?v=Mwieex7gFAs

is from the suburb of Rosa (Roza) 54? 54' 38? N, 61? 27' 15? E, ~23km
south of Chelyabinsk. This shows the path of the meteor being a few km
to the south.

I guess the first-mentioned video is from much the same area. If so,
with some knowledge of shock wave propagation speeds at various
altitudes, it should be possible to calculate the altitude and velocity
of the meteor at this point.

Another little-watched video with the smoke trail almost overhead is:

  http://www.youtube.com/watch?v=64gXz9W2oyQ

This is supposedly from Emanzhelinsk / Yemanzhelinsk, which is further
south still. I think this shows the smoke trail to be somewhat to the
north, with the initial view of the trail being at the western end.

This would enable the track of the meteor to be located just a few km
north of this location, somewhere between Roza and Emanzhelinsk /
Yemanzhelinsk.


http://maps.google.com/maps?q=Russia,+Chelyabinskaya+oblast,+Rosa&hl=en&ll=54.913725,61.42868&spn=0.584928,1.087646&sll=-37.73563,145.07369&sspn=0.050298,0.067978&oq=Rosa+Chely&t=h&hnear=Roza,+Korkinsky+District,+Chelyabinsk+Oblast,+Russia&z=10

  - Robin

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Received on Sat 16 Feb 2013 08:15:08 PM PST