PLEASE NOTE:
*
CCNet DIGEST, 5 February 1999
-----------------------------
(1) MINOR PLANET 10000: SEARCHING FOR THE RIGHT CANDIDATE
Minor Planet Center
<http://cfa-www.harvard.edu/mpec/J99/J99C03.html>
(2) PLANETARY SOCIETY AWARDS THREE NEW GENE SHOEMAKER NEO GRANTS
Bill McGovern <tps.wm@mars.planetary.org>
(3) REPORT FROM THE STARDUST EDUCATORS FELLOWSHIP PROGRAM
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(4) EFFECTS OF ENVIRONMENTAL STABILITY & INSTABILITY ON
MACROEVOLUTION
S. Chiba, SHIZUOKA UNIVERSITY
====================
*MINOR PLANET 10000: STILL SEARCHING FOR A NEW CANDIDATE
From Benny J Peiser <b.j.peiser@livjm.ac.uk>
Further to the Editorial Notice on MPEC 1999-C03, which I posted
on
today's CCNet DIGEST [below], I should make clear that an
important statement
at the end of the MPEC was inadvertently removed. This statement
indicated that the notice was prepared (for printing in the Minor
Planet Circulars) already on February 2, 1999, i.e. before the
IAU
General Secretary's statement about the withdrawal of Pluto as a
potential candidate for Minor Planet 10000. In other words, we
need NEW
suggestions for suitable candidates other than Pluto for this
nomenclatura.
Benny J Peiser
(1) MINOR PLANET 10000: SEARCHING FOR THE RIGHT CANDIDATE
From the Minor Planet Center
<http://cfa-www.harvard.edu/mpec/J99/J99C03.html>
M.P.E.C. 1999-C03
Issued 1999 Feb. 4, 16:04 UT
The Minor Planet Electronic Circulars contain information on
unusual
minor planets and routine data on comets. They are published on
behalf
of Commission 20 of the International Astronomical Union by the
Minor
Planet Center, Smithsonian Astrophysical Observatory, Cambridge,
MA
02138, U.S.A.
BMARSDEN@CFA.HARVARD.EDU
or GWILLIAMS@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html
EDITORIAL NOTICE
On 1801 Jan. 1 Guiseppe Piazzi discovered the object between Mars
and
Jupiter that he called Ceres Ferdinandea, "the eighth
planet".
Following the discovery a year later of a similar object, and in
subsequent years further objects in what might be termed the
"Cisjovian
Belt", Piazzi's discovery eventually became known under
either the name
Ceres or the symbol (1), where the numeral, originally placed
inside a
complete circle, indicated that this was the first object found
in that
region of the solar system. By 1849 the sequence of discoveries
in the
region had reached (10), and 1868 saw the discovery of
(100). By 1923,
when (1000) was announced, the set of objects, while still mainly
members of that Cisjovian Belt (also known simply as the
"Asteroid
Belt", or "Main Belt" of "minor
planets"), also included objects that
approached within 0.1 AU of the earth or extended out to the
orbit of
Saturn.
Next month, we shall pass (10000) in what is a collection of
small
objects that are not obviously cometary (although three members
do also
have well-documented dual status in the Catalogue of Cometary
Orbits)
and travel around the sun in independent orbits (i.e., satellites
are
excluded) that are well determined (i.e., with one exception that
will
surely be eventually remedied, the positions of the objects are
very
precisely predictable). Again, although the vast majority of the
objects are in the Cisjovian Belt, there are members that are at
perihelion significantly closer to the sun than Mercury or are at
aphelion beyond the orbit of Neptune. It has been traditional to
have a
special celebration with each thousandth numbering. For example,
(1000)
was named in honor of the discoverer of Ceres, (2000) in honor of
the
discoverer of Uranus, (5000) in honor of the International
Astronomical
Union and (6000) in honor of the United Nations. Obviously, it
would be
appropriate to have some very special celebration to acknowledge
(10000).
Most readers of these Circulars will be aware of recent
discussions in
the press concerning a proposal that the number (10000) should be
given
to Pluto. The principal reasoning for this is the recognition
during
the past few years that Pluto was the first discovered and
largest
known member of the "Transneptunian Belt" (sometimes
called the "Kuiper
Belt" or "Edgeworth-Kuiper Belt") of small objects
beyond Neptune that
possess some similarity, at least dynamically, to bodies in the
Cisjovian Belt. Although as many as 95 members (or possible
members) of
the Transneptunian Belt are now listed, most of the orbital
solutions
are very weak, and none of the bodies has so far been included in
the
collection of those with "guaranteed" orbit
determinations. A few of
the discoveries from 1992-1994 are now
approaching this state, which will also allow them to receive
permanent names.
Although it is not unlikely that further Transneptunian Objects
as
large as Pluto will be discovered in the future, Pluto obviously
holds a very special place in our appreciation of this new
population,
and by assigning to it the number (10000), we should guarantee
that
Pluto will be at the head of the Transneptunian list. It is also
very
important to affirm that there is absolutely no implied
"demotion" or
"reclassification" of Pluto from its position in the
list of the
"planets" (or "major planets" or
"principal planets"). Unfortunately,
many of the articles that have appeared in the press have
accidentally
(or deliberately) misinterpreted this issue. As with (2060) =
95P/Chiron, (4015) = 107P/Wilson-Harrington and (7968) =
133P/Elst-Pizarro, where the choice of "minor planet"
or "comet"
designation depends on the context, we are proposing that Pluto
would
have dual status as a "major" and a "minor"
body. Readers of these
Circulars, in particular, will appreciate that Pluto is
sufficiently
fainter than the other major planets that it can be confused with
many
other minor planets. We have in fact identified observations of
Pluto
several times during the past couple of years in data reported by
the
survey programs for Near-Earth Objects, and some astrometric
observers
specifically report to us observations of Pluto. There is
currently no
outlet for publishing these observations. It should be
emphasized that
the number (10000) would be used only in the context of
publishing such
observations or in matters directly related to Pluto's place in
the
Transneptunian Belt.
Much has been made in the press that the IAU is
"voting" on Pluto's
status, and at least one astronomical organization issued a press
release on the subject. Members of the public seem completely
baffled
by this kind of attention. The question of relevance to the
readers of
these Circulars concerns the numbering and naming of (10000).
Indeed,
the IAU Small Bodies Names Committee has already been working on
this
particular matter for the past month or so. Progress is slow and
uncertain, however, and there are some who think that democracy
would
be better served by seeking opinions from a larger, but informed
community. The astronomers, amateur and professional, who
contribute
material to these Circulars--astrometric observations,
identifications,
orbit determinations--are such an informed community.
Accordingly, any reader with an opinion on the subject is invited
to
e-mail it to us at the Minor Planet Center, preferably using the
address mpc@cfa.harvard.edu.
Such a message could consist of a brief
statement such as "I approve (10000) Pluto" or "I
do not approve
(10000) Pluto", although the value of the latter choice
would be
augmented if an appropriate alternative suggestion were made for
(10000). Brief comments on the subject (preferably constructive)
would also be welcome, and writers are encouraged to identify
themselves. Modern bureaucracy rarely pays much attention to
comments
from even an informed public, but since this issue is of concern
principally to our readers (more so, in fact, than to many
professional
astronomers with little or no interest in solar-system astronomy
who
just happen to be serving on a committee), we feel that it is
appropriate for us to solicit advice in this way. Your early
response
is desirable. It is not necessary that you actually subscribe to
these
Circulars in order to respond. Appropriate responses will be
examined
and considered in connection with the deliberations by the Small
Bodies
Names Committee by their deadline of Feb. 26.
Brian G. Marsden (C) Copyright 1999 MPC
M.P.E.C. 1999-C03
======================
(2) PLANETARY SOCIETY AWARDS THREE NEW GENE SHOEMAKER NEO GRANTS
From Bill McGovern <tps.wm@mars.planetary.org>
NEWS RELEASE
The Planetary Society
65 N. Catalina Avenue, Pasadena, CA 91106-2301 (626) 793-5100 Fax
(626)
793-5528 E-mail: tps@mars.planetary.org
Web: http://planetary.org
For Release: February 3, 1999
Contact: Bill McGovern/Susan Lendroth
Planetary Society Awards Three New Gene Shoemaker NEO Grants
Three researchers have been selected to receive Planetary Society
Gene
Shoemaker Near Earth Object Grants. Named for one of the
pioneers in
the field, the grants fund programs in the discovery and tracking
of
near-Earth objects -- asteroids and comets with Earth-crossing
orbits
that could impact our planet with devastating results. Special
emphasis
is given to international and amateur observers.
Only about 5% to 10% of the estimated total number of
one-kilometer or
larger objects that cross Earth's orbit have been discovered.
"Although
the rate of NEO discovery has accelerated recently as new
professional
survey programs have come on line, we are still shy of the widely
recommended rate needed to find 90% of the near-Earth asteroids
larger
than one kilometer within a decade," said Dan Durda, an
asteroid
researcher at the the Southwest Research Institute's Boulder,
Colorado
office, and coordinator of the Planetary Society's Gene Shoemaker
NEO
Grant program. Even though various astronomical groups and NASA
advisory committees have recommended that discovery of NEOs be
accelerated, government support for searches and follow-up
programs
remains modest.
The 1999 Gene Shoemaker NEO Grants, totaling $27,000 (US), have
been
awarded to an international collection of researchers: Stefan
Gajdos of
the Slovak Republic, Paulo Holvorcem of Brazil, and Frank
Zoltowski of
Australia.
Gajdos is a professional astronomer with the Institute of
Astronomy in
Bratislava in the Slovak Republic. His grant monies will be
used to
upgrade his program's equipment and software, to fund needed
computer
services, and to create a public outreach program.
Holvorcem, a teacher at the Universidade Estadual de Campinas in
Brazil, will use his Gene Shoemaker NEO Grant to upgrade
automation of
equipment at his observatory, freeing a number of volunteer
observers
to spend more time conducting data analysis and taking more
exposures
during each observation session.
Zoltowski is an amateur astronomer who conducts NEO searches in
the
small town of Woomera in the South Australian outback. Grant
money will
enable Zoltowski to upgrade his charge-coupled device (CCD)
camera,
improving his ability to detect NEOs in sky images and confirm
their
orbits in a series of exposures.
A Swarm of Near-Earth Objects
Earth travels through a swarm of near-Earth objects of various
sizes
and orbits. Scientists have only recently begun to
understand the
significant contribution NEOs have made to the evolution of Earth
--
and life on our planet. It is now believed that impacts from
comets and
asteroids have shaped the evolution of all planets in our solar
system.
So far, more than 600 NEOs have been discovered; more than 280 of
these
are larger than one kilometer across. Scientists estimate,
however,
that about 2,000 NEOs larger than one kilometer and 150,000 to
100
million objects larger than 100 meters in size exist.
NEOs have collided with Earth in the past with devastating
results. The
Chicxulub crater off the north coast of Mexico's Yucatan
Peninsula was
created by an Earth-colliding meteor 65 million years ago, a
globally
devastating event that is believed to have wiped out the
dinosaurs.
Even relatively small objects impacting our planet or exploded in
Earth's atmosphere can wreak considerable havoc.
The Gene Shoemaker NEO Grants
Gene Shoemaker was a leader in the study of impact structures and
an
advocate for NEO discovery and tracking programs before his death
in
1997. Shoemaker was the first scientist to demonstrate that the
mile-wide crater in Arizona -- now known as Meteor Crater -- was
the
result of a catastrophic impact by an asteroid 50,000 years
ago. Prior
to Shoemaker's work, Meteor Crater was believed to be the remnant
of an
extinct volcano.
The Gene Shoemaker NEO Grants are awarded to amateur observers,
observers in developing countries, and professional astronomers
who,
with seed funding, could greatly increase their programs'
contributions
to this critical research.
Funding for the Gene Shoemaker NEO Grant program comes from the
Planetary Society's 100,000 members, whose voluntary dues and
donations
permit targeted support of research and development programs in a
number of areas.
An international advisory group recommends candidates to receive
the
grant awards. The advisory group includes grant coordinator
Daniel D.
Durda, as well as noted near-Earth object scientists Dr. Richard
Binzel
of the Massachusetts Institute of Technology, Dr. Clark Chapman,
also
of the Southwest Research Institute, Dr. Andrea Carusi of the
Spaceguard Foundation, and Dr. Brian Marsden of the Smithsonian
Astrophysical Observatory.
Society-Funded ROTSE Camera Images Gamma Ray Burst
The Planetary Society has funded many NEO efforts in the past,
including start-up money for the Robotic Optical Transient Search
Experiment (ROTSE) in Los Alamos, New Mexico. Operated by a team
led by
Dr. Carl Akerlof of the University of Michigan and including
astrophysicists from Los Alamos and Lawrence Livermore National
Laboratories, ROTSE recently made astronomical history on January
23,
1999, when it discovered an unusual transient optical signal in
images
of the sky where a gamma ray burst had been reported just 22
seconds
earlier.
ROTSE is a multipurpose instrument, designed to continuously map
the
entire visible evening sky, collecting data that can be examined
for
near-Earth objects, as well as variable stars and supernovas as
they
occur. When a gamma ray burst occurs, such as the one detected by
orbiting satellites on the morning of January 23, ROTSE
interrupts its
regular sky-mapping activity and automatically swings to the sky
coordinates provided by the satellites. In only a few seconds,
ROTSE
began taking a new series of many images, capturing the first
gamma ray
burst ever recorded in images.
Astronomers are not certain what produces gamma ray bursts, but
possible causes include the mergers of two neutron stars, two
black
holes, a neutron star and a black hole, or the explosion of a
so-called
hypernova, which is theorized to be a type of supernova or
exploding
star.
-o0o-
For more information, contact Bill McGovern or Susan Lendroth at
(626)
793-5100 or by e-mail: (Bill) tps.wm@mars.planetary.org
(Susan)
tps.sl@mars.planetary.org
Carl Sagan, Bruce Murray and Louis Friedman founded the Planetary
Society in 1980 to advance the exploration of the solar system
and to
continue the search for extraterrestrial life. With 100,000
members in
more than 140 countries, the Society is the largest
space-interest
group in the world.
Linda Wong
The Planetary Society
65 N. Catalina Ave.
Pasadena, CA 91106
(626) 793-5100
(626) 793-5528 (fax)
tps@mars.planetary.org
======================
(3) REPORT FROM THE STARDUST EDUCATORS FELLOWSHIP PROGRAM
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
I've been at Kennedy Space Center all week for the upcoming
STARDUST
launch. I just got back from the launch pad, and everything is
still on
schedule for launch in two days. The weather forecast is
excellent.
The STARDUST project has sponsored an Educators Fellowship
program,
where 26 educators from around the country are trained to give
workshops on comets, small bodies and on the STADUST mission. All
of
the STARDUST Fellows were flown into Florida for a 3-day training
workshop, and are also invited to watch the STADUST launch.
One of the
Fellows selected is Martin Horejsi, whom many of you may
recognize from
the (meteorite-)list. All of the Fellows arrived yesterday,
so I got
to meet Martin for the first time in person. Last night,
the workshop
training began, with presentations by Carolyn Shoemaker (of Comet
Shoemaker-Levy 9 fame), Don Brownlee (STARDUST Principal
Investigator
from the Univ. of Washington), Ken Atkins (STARUDST project
manager),
Ben Clark (STARDUST scientist from Lockheed-Martin), and Steve
Jones
(aerogel maker from JPL). We've invited Paul Wild to the
launch, who
discovered Comet Wild-2 in 1978 and will be visited by
STARDUST. Dr.
Wild arrived today and gave a lively talk to the Fellows
today. Fred
Whipple ("dirty snowball" theorist) has also been
invited and will
arrive here tomorrow.
Ron Baalke
=====================
(4) EFFECTS OF ENVIRONMENTAL STABILITY & INSTABILITY ON
MACROEVOLUTION
S. Chiba: A mathematical model for long-term patterns of
evolution:
effects of environmental stability and instability on
macroevolutionary
patterns and mass extinctions. PALEOBIOLOGY, 1998, Vol.24, No.3,
pp.336-348
SHIZUOKA UNIVERSITY, INST BIOL & EARTH SCI,836 OYA,SHIZUOKA
422,JAPAN
A simple mathematical model to examine the relationships between
environmental instability and long-term macroevolutionary trends
is
presented. The model investigates the evolutionary changes that
occur
in certain population characters in an environment with physical
disturbance. These quantitative genetic characters are related to
intrinsic growth rates and mean carrying capacity. The model
assumes
that individual fitness is determined by these characters. I
examine
the likelihood of extinction under different degrees of
environmental
instability and for rapid change of environmental instability.
The
model suggests that characters that promote a high intrinsic
growth
rate and a low carrying capacity tend to evolve in the most
unstable
environments. This suggests that small body size, high fecundity,
and
simple forms evolve in unstable environments. The extinction
probability of a population is the lowest for taxa possessing
K-selected characters in the most stable environment. However,
the
extinction probability of a species (metapopulation) becomes
lowest
for r-selected species living in the most unstable environment
and
for the K-selected species living in the most stable environment,
and
it becomes the highest for taxa living in a moderately unstable
environment. Increasing environmental instability changes the
extinction probabilities of different taxa in different ways, due
to
differences in phenotypes and environments. The effect of
environmental change is most serious for the K-selected taxa in
the
most stable environment. This also suggests that a continuously
stable environment increases the extinction probability of taxa
when
environmental change occurs. Although catastrophic changes in
environments are not presumed, these results are consistent with
the
existence of two 'macroevolutionary regimes' in which a taxon's
extinction rate and its characters differ for mass extinction and
normal extinction. Mass extinction can occur as a result of
long-term
adaptation to a stable environment following a minor change of
environment without catastrophes. Copyright 1998, Institute for
Scientific Information Inc.
----------------------------------------
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