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Re: Peekskill Orbit?
Matt Morgan schrieb:
> I was just wondering if the orbit of the Peekskill meteorite has ever
> been projected since it was captured on videotape? If anyone has
> details
> please post. Thanks!
> --
> Matt Morgan
> Mile High Meteorites
> http://www.mhmeteorites.com
> P.O.Box 151293
> Lakewood, CO 80215-9293
> "For a geologist, life is a field trip"
Hello Matt, hello List,
Here is some info about the Peekskill Fireball:
The Peekskill meteorite is the fourth meteorite in history for which
there is a known orbit. The orbital parameters are given below. The
parent body of the Peekskill meteorite had an aphelion distance of 2.1
a.u., which indicates that it was periodically placed at the inner edge
of the main asteroid belt.
Orbital Parameters ReducedValue Error Terms
Semimajor axis 1.49 AU 0.03 AU
Eccentricity 0.41 0.01
Perihelion distance 0.886 AU 0.004 AU
Argument of perihelion 308° 1°
Long. ascending node 17.030° 0.001°
Inclination 4.9° 0.2°
Orbital period 1.82 yr 0.05 yr
VIDEO OBSERVATIONS OF THE PEEKSKILL METEORITE FIREBALL: ATMOSPHERIC
TRAJECTORY AND ORBIT.
(Meteoritics 29-4, 1994, 455)
Ceplecha Z.l, Brown P.2, Hawkes R.L.3, Wetherill G.4, Beech M.5, and
Mossman K.3
1Department of Interplanetary Matter, Astronomical Institute of the
Academy of Sciences, 251 65 Ondrejov Observatory, Czech Republic
2Department of Physics, University of Western Ontario, London, Ontario,
N6A 3K7, Canada
3Department of Physics, Engineering and Geology, Mount Allison
University, Sackville New Brunswick, EOA 3CO, Canada
4Carnegie Institution of Washington, Department of Terrestrial
Magnetism, 5241 Broad Branch Road, NW, Washington DC 20015, USA
5Department of Astronomy, University of Western Ontario, London,
Ontario, N6A 3K7, Canada.
At 23:48 UT (± l min) on October 9, 1992, a fireball, brighter than the
full Moon, appeared over West Virginia, traveled some 700 km in a
northeasterly direction, and culminated in at least one meteorite
impact. A 12.4-kg ordinary chondrite (H6 monomict breccia) was recovered
in Peekskill, New York. Fortuitously, the event was captured on several
video recordings.
Peckskill is only the fourth meteorite to have been recovered for which
detailed and precise data exist on the meteoroid atmospheric trajectory
and orbit. Consequently, there are few constraints on the position of
meteorites in the solar system before impact on Earth. In this talk, the
preliminary analysis based on 5 video recordings of this fireball (from
all existing 15 video recordings) will be given.
Preliminary computations revealed that the Peekskill fireball was an
Earth-grazing event, the third such case with precise data available.
The body, with an initial mass of the order of 10^4 kg and with initial
velocity of 14.7 km/s (geocentric velocity of 10 km/s) was in a
precollision orbit with a= 1.5 AU, an aphelion of slightly over 2 AU, an
inclination of 5° and an orbital revolution of 1.8 yr. The
no-atmosphere trajectory over the Earth's surface would have led to a
perigee of 22 km, but the body never reached this point due to
tremendous fragmentation and ablation. The dark flight of the recovered
meteorite started from a height of 30 km, when the velocity dropped
below 3 km/s, and the body continued an additional horizontal distance
of 50 km without ablation, until it hit a parked car in Peekskill, New
York, with a vertical velocity of about 80 m/s.
Our observations are also the first video records of a bright fireball
and the first motion pictures of a fireball with an associated
meteorite. During the second half of its flight, the fireball exhibited
extensive fragmentation with several dozen individual fragments visible
on some video frames. A maximum simultaneous separation of fragments was
>20 km. At least 70 pieces are visible on two high-resolution still
photographs of the event. Details on the fragmentation dynamics of the
body will be presented, and the results of photometric work will be
discussed.
Work is continuing on the further refinement of the atmospheric
trajectory and orbit. We anticipate improvements through measurements
from additional digitized video frames, more reliable positional
measurements of reference objects, incorporation of data from additional
stations and better modeling of ablation and deceleration.
Hope this is helpful.
Best wishes from Germany
Bernd
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