[meteorite-list] Radar signatures associated with the VA Beach Fireball, 29 Mar 09

Fries, Marc D marc.d.fries at jpl.nasa.gov
Wed Apr 1 14:40:42 EDT 2009


Howdy ladies and gents

    I have looked over the radar data from the VA Beach fireball this past
Sunday (I¹m calling it VA Beach because that was the location of the closest
eyewitness).  I believe there is a consistent debris trail in the data.
This track in the data evolves over a forty minute period and trends towards
the ESE, while all the clouds in the radar data move in a ENE to NEN
direction.  Either the debris was generated below the jet stream or we
over-estimated the effects of the jet stream, but that is something for me
to figure out later on.

    Here is my data from that meteor.  Click on each image for a
description:

http://s653.photobucket.com/albums/uu251/mfries/

    The available eyewitnesses converge well as to the direction of the
fireball.  Note that the VA Beach astronomers estimate the distance ­ the
last radar return is only 20 km removed from their estimate.  The debris
trail appears mostly over the Chesapeake, but the farthest downrange portion
crosses the Delmarva peninsula near the town of Johnsontown.  The western
end of the track (i.e. the first radar data to appear) also appears over
land (just barely) near Stingray Point, VA.  Note that this is uncorrected
for wind drift.  Surface winds were out of the SES at 5mph with 20 mpg gusts
(from Norfolk, VA met data), and I placed a crude correction of 3.3 mi on my
Google Earth image (5mph over 40 minutes after the fireball reports).
Basically, the position of the debris cloud should indicate a northeastern
limit for the actual position of fallen meteorites.

    My brother hasn¹t had a chance to look this over yet; I¹m jumping ahead
of him a bit because I¹m reasonably convinced that I¹m looking at a meteor
trace in the data.

    Disclaimer: Be advised that this information comes with no guarantees of
any kind and represents my interpretation only.  This is provided for
information purposes only, and neither I nor JPL assume liability for costs
and/or personal harm that may arise from personal decisions based on this
information.

Cheers,
MDF 




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