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(meteorobs) Excerpts from "CCNet 51/2001 - 3 April 2001"
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From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 3 April 2001
Date: Tue, 3 Apr 2001 14:13:41 +0100
CCNet 51/2001 - 3 April 2001
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(1) TAGISH LAKE METEORITE DATES BACK TO ORIGINS OF SOLAR SYSTEM
Ron Baalke <baalke@jpl.nasadot gov>
[...]
(10) FRAGMENTS FROM THE SKY
Colin Keay <myrcol@hunterlinkdot net.au>
(11) EFFECTIVE STABILITY OF THE TROJAN ASTEROIDS
Skokos C, Dokoumetzidis A
[...]
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(1) TAGISH LAKE METEORITE DATES BACK TO ORIGINS OF SOLAR SYSTEM
>From Ron Baalke <baalke@jpl.nasadot gov>
http://www.ottawacitizen.com/national/010402/5019000.html
Yukon meteorite dates back to origins of the solar system
Tom Spears
The Ottawa Citizen (Canada)
April 2, 2001
The 200-tonne meteor that blew up over the Yukon last year is turning out to
be older than any other known meteorite, older than our planet, probably the
oldest matter ever to come to Earth.
Chunks of space rock pulled from a lake on the Yukon-British Columbia border
probably formed as other planets did, condensing from the giant cloud of gas
that swirled around our sun as it first came into existence.
The clumps of grey-black matter may also be the oldest meteorite ever
discovered, older than Earth, and therefore our best look at the raw
materials from which our solar system was built.
Full story here:
http://www.ottawacitizen.com/national/010402/5019000.html
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* LETTERS TO THE MODERATOR *
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(10) FRAGMENTS FROM THE SKY
>From Colin Keay <myrcol@hunterlinkdot net.au>
Hello Benny:
One mystery solved.
Today I travelled to Glen Oak, 50k north of Newcastle, where the jet-black
fragment described in my last communication landed.
There was the chimney of a slow combustion heater nearby. I took off the
hood and found some crustaceous material identical to the sample I had been
given. I was told that the stove was fueled by ironbark hardwood from
surrounding forests, so I presume the volatiles given off must have bonded
the smoke particles together to form the very low density material.
The noise on the thin iron roof must have been a few heavy drops of rain. As
for the light seen just prior to the sounds it's anybody's guess. The time
of fall coinciding with passage under the orbital plane of Mir was purely
coincidental.
So sorry about the false alarm. I wish all of our solutions were as
unequivocal.
Cheers
Colin Keay
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(11) EFFECTIVE STABILITY OF THE TROJAN ASTEROIDS
Skokos C, Dokoumetzidis A: Effective stability of the Trojan asteroids
ASTRONOMY AND ASTROPHYSICS 367: (2) 729-736 FEB 2001
We study the spatial circular restricted problem of three bodies in the
light of Nekhoroshev theory of stability over large time intervals. We
consider in particular the Sun-Jupiter model and the Trojan asteroids in the
neighborhood of the Lagrangian point Lq. We find a region of effective
stability around the point Lq such that if the initial point of an orbit is
inside this region the orbit is confined in a slightly larger neighborhood
of the equilibrium (in phase space) for a very long time interval. By
combining analytical methods and numerical approximations we are able to
prove that stability over the age of the universe is guaranteed on a
realistic legion, big enough to include one real asteroid. By comparing this
result with the one obtained for the planar problem we see that the regions
of stability in the two cases are of the same magnitude.
Addresses:
Skokos C, Acad Athens, Res Ctr Astron, 14 Anagnostopoulou Str, Athens 10673,
Greece.
Acad Athens, Res Ctr Astron, Athens 10673, Greece.
Univ Athens, Sch Pharm, Athens 15771, Greece.
Copyright ) 2001 Institute for Scientific Information
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