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(meteorobs) Excerpts from "CCNet 119/2000 - 16 November 2000"
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From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 16 November 2000
Date: Thu, 16 Nov 2000 13:43:33 -0000
CCNet 119/2000 - 16 November 2000
---------------------------------
[...]
(2) LEONID METEOR SHOWER: SOWING THE SEEDS OF LIFE?
Space.com, 15 November 2000
(3) LEONIDS 2000: NICE METEOR SHOWER POSSIBLE, ANOTHER STORM UNLIKELY
Cosmic Mirror, #209, 13 November 2000
(4) WANTED: LEONID METEOR SPOTTERS
Space Weather News
(5) ON THE SMALL ASTEROID 1994 GV
G. Sitarski
(6) CHAOTIC EVOLUTION OF (719) ALBERT, THE RECENTLY RECOVERED MINOR PLANET
K. Tsiganis & H. Varvoglis
(7) DIFFUSION IN A SYMPLECTIC MAP WITH APPLICATION TO ASTEROID MOTION
L.Y. Zhou et al.
[...]
=================
(2) LEONID METEOR SHOWER: SOWING THE SEEDS OF LIFE?
>From Space.com, 15 November 2000
http://www.space.com/cgi-bin/email/gate.cgi?lk=T3&date=001115&go=/searchforl
ife/leonids_biology_001115.html
By Robert Roy Britt
Data from instruments flown on airplanes during last year's Leonid meteor
shower show that the seeds of life, long suspected to exist in comet dust,
could have survived a fiery passage from space to Earth's ancient
atmosphere.
A range of findings, reported by an international team of NASA-led
scientists, provide support for panspermia, which holds that life on Earth
did not spring up spontaneously out of some primordial soup, but was instead
seeded from space.
"Findings to date indicate that the chemical precursors to life -- found in
comet dust -- may well have survived a plunge into early Earth's
atmosphere," said astronomer Peter Jenniskens of the Ames Research Center
and the SETI Institute.
The studies were published in a November 14 special edition of the
Netherlands journal Earth, Moon and Planets.
Sowing the seeds
The idea that the seeds of life, or life itself, constantly fall from space
is the central idea of panspermia. Not only did life on Earth begin this
way, the concept holds, but the genetic pool is constantly modified, even
today.
Many mainstream scientists have long derided panspermia. But the view has
shifted noticeably in recent months.
Other researchers have shown that meteors both small and large do not heat
up as much as previously thought, allowing the possibility that dormant life
could arrive on an incoming space rock or, just possibly, embedded in the
dust grain of a comet.
Jenniskens and others said all this work at least supports the notion that
life's recipe -- in the form of organic molecules -- can survive the trip
into the atmosphere.
Chandra Wickramasinghe, a leading proponent of panspermia, cheered the
newest work.
"I think the results reported by NASA are clear proof that bacterial
particles could survive, hence vindicating panspermia," Wickramasinghe said.
He and astronomer Sir Fred Hoyle have, since the 1970s, argued that organic
particles of bacterial sizes survive entry through the atmosphere.
"However, there is still a tendency to interpret results like this as merely
showing that organics, rather than life, are being added to the Earth, but
the trend is surely moving towards panspermia," Wickramasinghe told
SPACE.com.
FULL STORY at
http://www.space.com/cgi-bin/email/gate.cgi?lk=T3&date=001115&go=/searchforl
ife/leonids_biology_001115.html
=================
(3) LEONIDS 2000: NICE METEOR SHOWER POSSIBLE, ANOTHER STORM UNLIKELY
>From Cosmic Mirror, #209, 13 November 2000
http://www.geocities.com/skyweek/mirror/209.html
Contrary to some sensationalist predictions already making the rounds
another Leonid meteor storm, i.e. thousands of meteors per hour, is highly
unlikely this year - a repeat of last years sky show (see Updates # 158 and
186 story 2 plus eyewitness reports from Jordan and France) remains likely
for next year, however (see the links in this announcement). In 2000, the
Earth will not come close to any of the dust trails which comet
Tempel-Tuttle has left behind, and thus most experts are not expecting more
than a few hundred meteors per hour - and because of the last-quarter Moon
in the sky, you won't even see that number, as the sky brightness will
render fainter meteors invisible.
Still it is worth to go out and watch on the morning of November 18th. A
first peak, visible from western Europe and Africa (including central
Europe) and NE South America, is expected around 3:44 UTC, which is 4:44
a.m. local time for most of the favored continental European and African
locations, 3:44 a.m. for the British Isles, mainland Portugal, and the
Canary Islands, and 1.44 a.m. for eastern Brazil. A second peak, visible
from large parts of North America, Central America, and NW South America, is
expected around 7:51 UTC, which is 3:51 a.m. Atlantic Standard Time, 2:51
a.m. Eastern Standard time, 1:51 Central Standard Time, and 0:51 a.m.
Mountain Standard Time. There is also a very vague chance that enhanced
rates could be seen around 7:53 UTC on November 17th, also favoring North
America.
"At the times mentioned above," the International Meteor Organization
predicts, "an observer at the indicated locations may expect to see 50 to
100 meteors per hour. A veritable meteor storm with several tens of meteors
per minute as last year is much less likely this year, but not ruled out.
Therefore, vigilance is called for! [...] In order to see meteors, the sky
must be clear and the selected observing site should preferentially be free
of light pollution; the less light, the more meteors will be seen! Notice
that Leonid meteors cannot be seen before around midnight. Hence, there is
no point in starting an observation earlier. Die-hards who do not want to
miss anything of the show should then continue to watch until dawn. People
who cannot afford to stay up that long should focus on a period of 1 to 2
hours centered around the predicted peak time for their region."
===============
(4) WANTED: LEONID METEOR SPOTTERS
>From Space Weather News for Nov. 15, 2000
http://www.spaceweather.com
The 2000 Leonid meteor shower is just around the corner. Forecasters expect
at least two outbursts of shooting stars as Earth passes through debris from
comet Tempel-Tuttle this Friday and Saturday. Spaceweather.com will post
current meteor counts and reports from around the world
beginning Thursday and continuing through the end of the shower. We invite
all our readers to participate and report what they see. All you need are
clear skies! Visit http://www.spaceweather.com for more information and
observing tips.
And don't forget NASA's live webcast of the Leonids from the stratosphere!
Visit http://www.leonidslive.com for details.
===========
(5) ON THE SMALL ASTEROID 1994 GV
G. Sitarski: ACTA ASTRONOMICA 50: (3) 417-419 2000
Minor planet 1994 GV was observed during only three days but it passed near
the Earth and ran over the 28-degree are on the sky. The orbit of this minor
planet crosses the Earth orbit in the descending node. It appeared that
according to this nominal orbit determined from the three-day observation
are, a very close approach of the asteroid to the Earth to within 0.000114
a.u, could happen in April 2008. However, our investigations of 600 randomly
selected orbits as well as a search of the impact orbit excluded a
possibility of a collision of 1994 GV with the Earth.
Copyright ) 2000 Institute for Scientific Information
Addresses:
Sitarski G, Univ Bialystok, Inst Theoret Phys, Lipowa 41, PL-15424
Bialystok, Poland.
Univ Bialystok, Inst Theoret Phys, PL-15424 Bialystok, Poland.
Polish Acad Sci, Space Res Ctr, PL-00716 Warsaw, Poland.
=============
(6) CHAOTIC EVOLUTION OF (719) ALBERT, THE RECENTLY RECOVERED MINOR PLANET
K. Tsiganis & H. Varvoglis: ASTRONOMY AND ASTROPHYSICS 361: (2) 766-769 SEP
2000
On May 9 the Mirror Planet Center announced the re-discovery of the last
'lost' minor planet, (719) Albert. In this paper we study its orbital
evolution. We show that Albert follows an extremely chaotic orbit. typical
of near-Earth asteroids (NEAs) that are extracted from main belt resonances
through close planetary encounters. It will become an Earth-crosser and,
eventually, it will either be ejected from the solar system on a hyperbolic
orbit or will become a Sun-grazer, most probably within the next 5 Myrs.
Copyright ) 2000 Institute for Scientific Information
Addresses:
Tsiganis K, Univ Thessaloniki, Dept Phys, Sect Astronphys Astron & Mech,
GR-54006 Salonika, Greece.
Univ Thessaloniki, Dept Phys, Sect Astronphys Astron & Mech, GR-54006
Salonika, Greece.
===============
(7) DIFFUSION IN A SYMPLECTIC MAP WITH APPLICATION TO ASTEROID MOTION
L.Y. Zhou, Y.S. Sun, J.L. Zhou: CHINESE PHYSICS LETTERS 17: (10) 708-710
2000
In studying a 2-dimensional symplectic map, the exponential law and
algebraic law are observed in the diffusion of orbits in the phase space.
The diffusion time in the vicinity of an island is investigated carefully
and a logarithm law is found for the first time. The distribution of
asteroids in the main belt and the diffusion velocities in 3:2 and 4:3
resonances are discussed using this map. Copyright ) 2000 Institute for
Scientific Information
Addresses:
Zhou LY, Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China.
Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China.
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