[meteorite-list] Updated Lorton trajectory

From: Mike Hankey <mike.hankey_at_meteoritecentral.com>
Date: Wed, 27 Jan 2010 09:36:04 -0500
Message-ID: <f0a794131001270636u4a5c45f2x59fd330d5c129553_at_mail.gmail.com>

I guess this explains why it did so much damage?

On Wednesday, January 27, 2010, Rob Matson <mojave_meteorites at cox.net> wrote:
> Hi All,
>
> I finally received a good second image of the Lorton bolide smoke
> trail taken immediately after the fall (and before upper atmospheric
> winds distorted it). More importantly, the two images I have were
> taken from sufficiently different vantage points that a good 3D
> solution could be computed. (My early, somewhat hurried "first-cut"
> at the trajectory was based on only a single image, and a cobbling
> together of 50+ witness reports.) That first solution wasn't bad
> as far as the flight direction (NNE -> SSW); however, as steep as
> I made the entry angle, I didn't make it steep enough.
>
> The Lorton meteoroid entered at a surprisingly steep angle -- about
> 15 degrees from vertical! If upper atmospheric winds had been
> light, this would have made for a very tight strewnfield. But
> those winds were anything but light at the time of the fall. For
> instance, at 11-km altitude, the jet stream was over 90 knots!
> Even down at 5-km altitude, the wind was over 40 knots.
>
> So here are my new impact predictions as a function of mass.
> The distance and bearing columns are in miles and degrees,
> respectively, relative to the impact coordinates of the 308-gram
> mass:
>
> Mass ? Longitude Latitude Distance Bearing
> ----- ?--------- -------- -------- -------
> ?3 g ? ?-77.1383 ?38.7130 ? 4.05 ? ?77.9
> 10 g ? ?-77.1635 ?38.7104 ? 2.68 ? ?75.5
> 30 g ? ?-77.1804 ?38.7077 ? 1.75 ? ?74.0
> 100 g ? -77.1976 ?38.7043 ? 0.80 ? ?71.8
> 300 g ? -77.2116 ?38.7007 ? -0- ? ? ?N/A
> ?1 kg ? -77.2282 ?38.6965 ? 0.94 ? ?252.1
> ?3 kg ? -77.2415 ?38.6923 ? 1.72 ? ?250.2
> 10 kg ? -77.2560 ?38.6874 ? 2.57 ? ?249.0
>
> As before, these coordinates (when you connect the dots) trace
> out a curve of the estimated strewn field centerline. Unfortunately,
> the lightest (and presumably more numerous) fragments would have
> been windblown onto Ft. Belvoir. But there is still some room ENE
> of the doctor's office that is not on military land, and plenty
> of real estate in the "heavy direction" (WSW) if you're feeling
> lucky. ?--Rob
>
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Received on Wed 27 Jan 2010 09:36:04 AM PST