[meteorite-list] Maximum theoretical Earth impact velocity

From: Greg Crinklaw <crinklaw_at_meteoritecentral.com>
Date: Mon, 14 Apr 2014 16:49:01 -0600
Message-ID: <534C65DD.2070706_at_tularosa.net>

There is an all-sky camera at Apache Point Observatory, but it appears
to have been turned off until later that night. Observatories use them
so that remote observers can monitor the weather.

I dug around on the web to see if there is a camera on top of Mount
Baldy, perhaps at Magdalene Ridge Observatory, but with no luck. A
camera there would be ideally located. At the very least we might be
able to tell that it happened over the White Sands Missile Range or not.


On 4/14/2014 3:50 PM, Bill Cooke wrote:
> The information
>>> I found some info on the fall and here is some stats...
>>> vel 667.2 km/s beg 135.8 km end 40.8 km
> is from our Fireballs website and is an automatic, obviously incorrect solution to the event. There are 2 NASA cameras in southern New Mexico - one, at NMSU, collected decent data on the event, whereas the other one, located in Mayhill, saw only bright flashes through clouds, very similar to lightning. The automated software did the best it could to calculate a trajectory, but lightning events are often confused with fireballs, and it simply "went home to momma". On the plus side, we have been able to filter out most of the planes :/
> If you use the Fireballs website, please look at the videos. If one or more shows lightning, then you know the trajectory is crap. In general, any meteor solution with a speed higher than 72-73 km/s should be regarded with much skepticism.
> Most all sky meteor cameras are similar to the Sandia design and use relatively low resolution low light level cameras like the Watec 902H2. As a result, meteor trajectory precision is about 100 meters in normal cases, which translates to an uncertainty in speed of 5-10%. As mentioned by others, this affects the semimajor axis and eccenticity (size and shape of orbit) the most, with the orbital angles (inclination, argument of perihelion, and ascending node) being much better determined, usually to the 1% level. These are low precision orbits, good for statistical work, but individual examples should be used with care.
> Regards,
> Bill Cooke

Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico
Received on Mon 14 Apr 2014 06:49:01 PM PDT

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