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(meteorobs) Excerpts from "CCNet 117/2000 - 14 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, 14 November 2000
Date: Tue, 14 Nov 2000 11:53:05 -0000
CCNet 117/2000 - 14 November 2000
---------------------------------
[...]
(7) LEONIDS 2000: SPECTACULAR DISPLAY OR DAMP SQUIB?
ESA News <sciweb@estec.esadot nl>
(8) LEONID METEORS YIELD RICH ASTROBIOLOGY RESEARCH RESULTS
Ron Baalke <baalke@zagami.jpl.nasadot gov>
(9) HERE COMES THE LEONIDS
Thursday's Classroom for Nov. 13, 2000
(10) METEOROIDS 2001: FIRST ANNOUNCEMENT
Duncan Steel <D.I.Steel@salford.acdot uk>
[...]
======================================================================
(7) LEONIDS 2000: SPECTACULAR DISPLAY OR DAMP SQUIB?
>From ESA News <sciweb@estec.esadot nl>
One of the most exciting things about meteor showers is their sheer
unpredictability. Just when astronomers think they know all about a
particular shower, something happens to spring a surprise. One of the least
predictable of the annual meteor showers is the Leonids, which appears each
year around 16-18 November.
Although this year's shower is not expected to reach storm proportions, ESA
scientists are continuing their efforts to learn more about the cosmic
debris that is incinerated as it enters Earth's upper atmosphere.
Find out more about the Leonids at: http://sci.esa.int/leonids2000
======================================================================
(8) LEONID METEORS YIELD RICH ASTROBIOLOGY RESEARCH RESULTS
>From Ron Baalke <baalke@zagami.jpl.nasadot gov>
Kathleen Burton
Nov. 13, 2000
NASA Ames Research Center, Moffett Field, CA
650/604-1731, kburton@mail.arc.nasadot gov
RELEASE: 00-77AR
LEONID METEORS YIELD RICH ASTROBIOLOGY RESEARCH RESULTS
A team of NASA researchers and their collaborators report their findings
from last year's Leonid meteor storm in today's special issue of the journal
"Earth, Moon and Planets."
The scientists - all members of the NASA and U.S. Air Force-sponsored Leonid
Multi-Instrument Aircraft Campaign - discussed their results in a series of
astrobiology-related papers in the peer-reviewed journal. While their
findings covered a range of areas, the key results reported have
implications for the existence and survival of life's precursors in comet
materials that reach Earth.
"Last year's Leonid meteor storm yielded rich research results for NASA
astrobiologists," said Dr. Peter Jenniskens, a NASA astronomer based at Ames
Research Center and principal investigator for the airborne research
mission. "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."
Jenniskens and his international cadre of researchers think that much of the
organic matter in comet dust somehow survived the rapid heating of Earth's
atmospheric entry. "Organic molecules in the meteoroid didn't seem to burn
up in the atmosphere," he explained. They may have cooled rapidly before
breaking apart, he concluded.
Another manner in which organic matter can somehow survive the fiery plunge
into Earth's atmosphere was discovered by a team from the Aerospace
Corporation, Los Angeles, who detected the fingerprint of complex organic
matter, identical to space-borne cometary dust, in the path of a bright
Leonid fireball. This "fingerprint" is still under investigation to ensure
that trace-air compounds are not contributing to the detection.
Another finding with potentially important implications for astrobiology is
that meteors are not as hot as researchers had previously believed. "We
discovered that most of the visible light of meteors comes from a warm wake
just behind the meteor, not from the hot meteoroid's head," said Jenniskens.
This warm wake has just the right temperature for the creation of life's
chemical precursors, he said.
Utah State University researchers found that, during the meteors' demise in
the atmosphere, their rapid spinning caused small fragments to be ejected in
all directions, quite far from the meteoroid's head. This is an important
finding for astrobiology, because it means that meteors may be able to
chemically alter large amounts of atmosphere.
This year, the 2000 Leonid meteor shower is expected to peak twice -- once
on Thursday night November 16 and again on Friday night November 17.
Although not as strong as last year's storm, meteors will be visible across
the continental United States, with the East Coast predicted to provide the
best meteor viewing. Each night, optimal East Coast viewing will be at
approximately 2:50 a.m. (EST). West Coast observers can glimpse the showers
beginning after 11:00 p.m. (PST), and peaking between midnight and 1:30 a.m.
Astronomers recommend that, because this year's showers take place during a
last-quarter moon, optimal observing conditions demand a wide field of view,
with the moon behind trees or buildings.
An observing tool called the "Leonid MAC flux estimator" is available for
the general public at: http://leonid.arc.nasadot gov. It predicts how much
meteor activity is expected at a particular U.S. observing location. Further
images from 1999's meteor storm, information about "Earth, Moon and Planets"
and other Leonids information can be found at: http://amesnews.arc.nasadot gov
Astrobiology is the study of the origin, evolution, dissemination and future
of life in the universe. NASA's Ames Research Center, in the heart of
California's Silicon Valley, is the Center of Excellence for NASA's
astrobiology research. It is also the location of the central offices of the
NASA Astrobiology Institute, an international research partnership - among
NASA and non-NASA agencies and institutions - to further astrobiology
research.
======================================================================
(9) HERE COMES THE LEONIDS
>From Thursday's Classroom for Nov. 13, 2000
http://www.thursdaysclassroom.com
The 2000 Leonid meteor shower is just around the corner. This year's display
of 100 or so shooting stars per hour might not match the anticipated Leonid
meteor storm in 2001, but experts say it's still worth watching. This
week's episode of Thursday's Classroom includes lessons
and activities that will help kids (1) figure out where to look for Leonid
meteors, (2) prepare for a meteor watch, and (3) count the meteors they see.
For more information please visit: http://www.thursdaysclassroom.com
======================================================================
(10) METEOROIDS 2001: FIRST ANNOUNCEMENT
>From Duncan Steel <D.I.Steel@salford.acdot uk>
------------
>From Asta Pellinen-Wannberg
Dear colleagues,
Please find enclosed the 1st Announcement for the Meteoroids 2001 conference
in Kiruna, Sweden. Please feel free to pass this message on to anyone you
know who might be interested.
Looking forward to seeing you in Kiruna
Asta Pellinen-Wannberg, Local Organising committee
*********************************************************************
First Announcement on METEOROIDS 2001
Conference at the SWEDISH INSTITUTE OF SPACE PHYSICS, KIRUNA, SWEDEN
6-10 August 2001
This conference will be the fourth in a series of meteoroid meetings which
have been held every few years since 1993, the last being in Tatranska
Lomnica in 1998. It will accommodate a broad range of meteoroid research:
dynamics, sources and distribution of these bodies, the physics and
chemistry of their interaction process with the atmosphere as well as the
space weather aspects in the form of their hypervelocity impact threat to
spacecraft. Due to the high Leonid activity during recent years, much
research has been devoted to these topics with both traditional and new
optical, radar and in-situ methods from ground, airplane and spacecraft.
Due to the recent recurrence of the Leonids, a session on historical
observations of meteors and perspectives on meteor science will be included,
but most of the meeting will be devoted to new results, new observations and
new techniques. Much meteor stream modelling work has preceded the recent
Tempel-Tuttle visit; in 1998 the quite moderate Leonids extended over a day,
while in 1999 the sharp and much more intensive maximum was correctly
predicted. There has been another opportunity to observe the Leonids
(November 2000) and improve the models so the proposed conference is at a
very optimum time to provide a forum for an overview of progress in the
dynamics and modelling of meteor storms and valuable results are to be
expected on understanding important (e.g. satellite damage) commercial
interests.
In radar applications the data collection and signal processing techniques
have developed hugely within a few years. Besides the traditional VHF meteor
radars, large aperture VHF and UHF facilities as Arecibo and EISCAT have
been used for meteor studies. With these extremely sensitive instruments,
the mysterious head echo process can be studied with very high spatial and
time resolution observing the effects on the background ionosphere
simultaneously. Radars are important tools for studying the various origins
of the meteoroids. Recent work (the AMOR and Arecibo instruments) has been
able to provide definitive evidence for the expanding field of Interstellar
Particle detection.
In-situ measurements on meteoroids and the observation of the interstellar
particles with Ulysses spacecraft started a new era of space-borne
experiments. Observational data about the local interstellar medium and the
outer solar system including the Kuiper belt objects raise interest again in
the orbital and collisional evolution of meteoroids, including "icy"
meteoroids. In a similar way the observation of debris shells in
circumstellar systems bears a new application of the study of the
"meteoritic complex" from the fragmentation of large parent bodies to the
formation of a dust cloud.
New global problems such as indications of climate change are being tackled.
Meteoric constituents have an effect on the physics and chemistry of the
atmosphere at and below the deposition heights. Especially, it is important
to understand the impact of these on the artificial constituents. Studies of
how the addition of meteoric constituents affect different atmospheric
phenomena such as noctilucent clouds and ozone chemistry have increased in
interest. Studies of meteoroid chemical composition and the ablation
processes can even provide information about the state of early conditions
in the solar system.
Hypervelocity impact effects on spacecraft is a very important application
of the meteoroid science. The results from the meteor stream modelling
discussed above especially for meteor shower periods are important. The flux
of meteoroids large enough to penetrate the spacecraft and cause great
damage is very low even during the Leonids. The more numerous smaller
particles are much more dangerous since they can induce surface charging and
trigger spacecraft anomalies similar to the high speed solar wind.
Especially interesting is the relation between the meteor triggered
anomalies and high solar activity. The growing number of satellites and
consequently of space debris will rapidly increase the risks for impact
damage on spacecraft.
TOPICS
*******
The following scientific areas are proposed for this meeting:
* Historical observations and perspectives on meteoroids
* Dynamics, sources and spatial distribution of meteoroids including
sporadic, swarm and interstellar meteoroids
* Physics and chemistry of meteoroid interaction process in the atmosphere
including both head echo and trail effects
* Impacts of meteoric constituents on atmospheric phenomena
* Hypervelocity impact effects on spacecraft
* Leonids - meteor storms and their short-term environmental effects
With observations done with the following methods:
* Optical observations of meteors including cameras, telescopes and lidars
* Radar observations with meteor and large aperture radars
* In-situ measurements of meteoroids
SCIENTIFIC ORGANISATION COMMITTEE
***************************************
Prof. W.J. Baggaley, University of Canterbury, New Zealand
Prof. Oleg Belkovich, Kazan State University, Russia
Dr. Gerhard Drolshagen, European Space Agency, Netherlands
Prof. Eberhard Grun, Max-Planck-Institut fur Kernphysik, Germany
Dr. Robert Hawkes, Mount Allison University, Canada
Dr. Peter Jenniskens, NASA Ames Research Center, USA
Dr. Ingrid Mann, European Space Agency, Netherlands and
The University of Muenster, Germany
Prof. David D. Meisel, State University of New York, USA
Dr. Edmond Murad, Air Force Research Laboratory, USA
Dr. Asta Pellinen-Wannberg, Swedish Institute of Space Physics, Sweden
Dr. Vladimir Porubcan, Astronomical Institute SAV, Slovakia
Dr. Junichi Watanabe, National Astronomical Observatory of Japan, Japan
Prof. Iwan Williams, University of London, UK
LOCAL ORGANISATION COMMITTEE
***********************************
Asta Pellinen-Wannberg
Eivor Jonsson (secretary), meteoroids2001@irf.se
Christina Juren
Rick McGregor (webmaster), webmaster@irf.se
Birgitta Maatta
More information can be found on our web-site:
http://www.irf.se/Meteoroids2001/
which will now be continuously updated as we get more information.
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