PLEASE NOTE:
*
CCNet 6/2001 - 12 January 2001
------------------------------
"Rampaging Muslims burned down scores of hotels and bars in
a
northern Nigerian city in reaction to the lunar eclipse which
they
blamed on sinners, residents said on Wednesday. Paramilitary
police
battled gangs of Muslim youths in the streets of the largely
Islamic city
of Maiduguri for hours on Tuesday night. Residents said at least
40 hotels
or drinking houses were set ablaze. Similar violence was reported
in
Barma town 50 miles away where youths chanting Allahu Akbar (God
is Great)
took to the streets. "The immoral acts committed in these
places are
responsible for this eclipse," police quoted a youth leader
as saying."
--Space.com, 10 January 2001
(1) CHANDRA LINKS PULSAR TO HISTORIC SUPERNOVA IN 386 AD
NASA Science News for January 11, 2001
(2) STARDUST CAN SEE CLEARLY NOW -- JUST BEFORE EARTH FLYBY
NASA News <NASANews@hq.nasa.gov>
(3) LUNATICS AT WORK: MOON ECLIPSE SPARKS RIOTS BY MUSLIM
FANATICS
SPACE.com, 10 January 2001
(4) NASA BALLOON RESEARCH RIDES TO THE EDGE OF SPACE
Mark Hess <mhess@pop100.gsfc.nasa.gov>
(5) COMA BERENICIDS, YES; COMET CONNECTIONS, NO
Brian Marsden <brian@cfaps1.harvard.edu>
(6) EARTH IS THE MOST LIKELY PLACE FOR LIFE'S ORIGIN IN OUR SOLAR
SYSTEM
Steve Drury <s.a.drury@open.ac.uk>
(7) GRANDE CHALLENGE: A PRAGMATIC APPROACH TO DISASTER PREVENTION
&
MANAGEMENT
Andy Smith <astrosafe@yahoo.com>
(8) FORMATION OF IRON METEORITES
G.K. Benedix
(9) ACTIVE REGIONS ON THE SURFACE OF COMET 43P/WOLF-HARRINGTON
S. Szutowicz
(10) POSITIONAL ERRORS & THE PERTURBED TWO-BODY PROBLEM
H. Arakida
(11) ASTEROIDAL PROCESSING OF CHONDRITIC MATERIALS
P.A. Bland
(12) INTERNATIONAL INSTITUTIONS AND THE MANAGEMENT OF GLOBAL
RISKS
P.M. Haas
(13) AND FIMALLY: SPACE RESAERCH SPILLS ZE END FOR DYSLEXIA
The Scotsman, 12 January 2001
=================
(1) CHANDRA LINKS PULSAR TO HISTORIC SUPERNOVA IN 386 AD
From NASA Science News for January 11, 2001
http://science.nasa.gov/headlines/y2001/ast11jan_1.htm?list20392
New evidence from NASA's Chandra X-ray Observatory suggests that
a known
pulsar is the present-day leftover from a stellar explosion
witnessed by
Chinese astronomers in 386 AD. The discovery could force
astronomers to
rethink what they know about the ages of neutron stars.
January 11, 2001 -- New evidence from NASA's Chandra X-ray
Observatory
suggests that a known pulsar is the present-day counterpart to a
supernova
that exploded in 386 AD, a stellar explosion witnessed by ancient
Chinese
astronomers. If confirmed, this will be only the second known
pulsar to be
clearly associated with an historic event.
In roughly the past 2,000 years, less than 10 reports of probable
supernovae
have been archived, mostly by Asian astronomers. Until now, the
Crab Nebula
has been the only pulsar whose birth is associated with an
historic event,
the supernova of 1054 AD, making it the only neutron star with a
firm age.
"Determining the true ages of astronomical objects is
notoriously
difficult," said Victoria Kaspi of McGill University in
Montreal, Canada,
"and for this reason, historical records of supernova are of
great
importance."
Kaspi and colleagues, who presented their results yesterday at
the American
Astronomical Society meeting in San Diego, CA, used Chandra to
locate the
pulsar exactly at the geometric center of the supernova remnant
known as
G11.2-0.3. This location provides very strong evidence that the
pulsar, a
neutron star spinning 14 times per second, was formed in the
supernova of
386 AD, making it 1,615 years old.
Because pulsars, once they are formed, race away from the site of
the
supernova explosion, Chandra's ability to pinpoint the pulsar at
the
remnant's center implies the system must be very young.
"We believe that the pulsar and the supernova remnant
G11.2-0.3 are both
likely to be left over from the explosion seen by the Chinese
observers over
1,600 years ago," said Mallory Roberts of McGill University.
"While this is
exciting by itself, it also raises new questions about what we
know about
pulsars, especially during their infancies."
These questions arose when the research team of the Japanese
Advanced
Satellite for Cosmology and Astrophysics (ASCA) applied the
present spin
rate to current models to determine the pulsar's estimated
lifetime and
compared it to the age of G11.2-0.3. The result was an age of
roughly 24,000
years -- far predating the birth year of 386 AD.
To explain this contradiction, the Chandra team argues that this
pulsar may
have had approximately the same spin rate today as it did at its
birth. If
true, this could have important implications for conventional
wisdom
regarding pulsars, which may be spinning more slowly than
previously
thought.
Between mid-April and mid-May in the year 386 AD, the sudden
appearance of a
new star, presumably a supernova, was recorded by Chinese
observers in the
direction of the sky now known as the constellation of
Sagittarius. In the
1970s, radio astronomers discovered an expanding nebula of gas
and
high-energy particles, called G11.2-0.3, believed to be the
remnant of that
explosion. In 1997, a team of X-ray astronomers used ASCA to
discover a
pulsar in the same area of the sky.
NASA's Marshall Space Flight Center in Huntsville, AL, manages
the Chandra
program. The Smithsonian's Chandra X-ray Center controls science
and flight
operations from Cambridge, MA. These results were presented by
Vicki Kaspi
and Mallory Roberts, of McGill University, at the American
Astronomical
Society meeting in San Diego, CA. Also participating in the
research were
Gautum Vasisht from NASA's Jet Propulsion Laboratory, Pasadena,
CA; Eric
Gotthelf from Columbia University, New York City; Michael
Pivovaroff from
Thermawave, Inc., Fremont, CA; and Nobuyuki Kawai from the
Institute of
Physical and Chemical Research, Japan. In addition to their
appointments at
McGill, Kaspi is also affiliated with the Massachusetts Institute
of
Technology, Cambridge, and Roberts is a Quebec Merit Postdoctoral
Fellow.
The National Science Foundation and NSERC (Canada) also provided
funding for
this work.
===============
(2) STARDUST CAN SEE CLEARLY NOW -- JUST BEFORE EARTH FLYBY
From NASA News <NASANews@hq.nasa.gov>
Donald Savage
Headquarters, Washington,
DC
January 11, 2001
(Phone: 202/358-1547)
Martha J. Heil
Jet Propulsion Laboratory, Pasadena, CA
(Phone: 818/ 354-0850)
RELEASE: 01-06
STARDUST CAN SEE CLEARLY NOW -- JUST BEFORE EARTH FLYBY
After a few months of foggy vision, NASA's Stardust mission team
has
improved the spacecraft's navigation-camera resolution to nearly
normal,
just as Stardust is preparing to make a close flyby of the Earth
on Monday.
By heating the camera's optical path, the Stardust team was able
to help its
nearsighted spacecraft boil away contaminants that had been
deposited on
optical surfaces.
One year ago, the imaging team took pictures of a small lamp
inside the
optical path of the camera. The camera will be used to navigate
Stardust to
its 2004 encounter with Comet Wild 2
(pronounced "vilt-2"). Apparent contamination of the
navigation-camera
prevented a clear test-image of the squiggly line of the lamp's
filament,
and the lens seemed to be covered with a veil of light-scattering
material
that produced a blurry image.
The team concluded that the contamination might have been
released with
gases escaping from the spacecraft after its launch, and that
heating the
optical path of the camera might evaporate the
contaminant covering the camera lens. After a series of heating
cycles, they
retested the camera by taking more pictures of the lamp.
Pictures taken after the heating revealed that the zigzag line of
the lamp's
filament was visible again. Images of stars taken by the camera
are also
clearer. The team estimates the camera can now photograph stars
two
magnitudes (celestial degrees of brightness) better. The
navigation camera
has detected stars as faint as 9th magnitude, which should allow
the
spacecraft to perform its final navigation maneuvers during
approach to the
comet nearly at the time originally planned.
Now Stardust, on its journey to collect comet dust, is getting
ready to
springboard from Earth -- in a maneuver called a
"gravity-assist" -- when
the spacecraft passes closest to Earth on January 15, 2001.
Stardust was launched on February 7, 1999, into its first loop
around the
Sun. When Stardust passes by Earth at about 22,400 miles per hour
(or 10
kilometers per second), it will go into a slightly wider orbit
that will
allow it to reach the comet on January 2, 2004.
On Monday, January 15, Stardust will fly by a point just
southeast of the
southern tip of Africa, slightly more than 3,700 miles (6,000
kilometers)
from the surface at about 5:15 a.m. EST (3:15 a.m. PST).
Stardust may be visible to observers using sophisticated
telescopes with
charge-coupled device (CCD) detectors from the Pacific Ocean and
the Western
United States just after the spacecraft flies by Earth. Stardust
will not be
visible using binoculars.
A gravity-assist works like this: when a spacecraft closely
approaches a
planet, the planet's gravitational pull accelerates the
spacecraft and bends
the flight path. Mission designers account for this extra pull
and use it to
their advantage to boost spacecraft speed and direct
interplanetary
spacecraft to their targets. Like a windup before the pitch, the
Earth
gravity-assist will sling Stardust into the right path to meet
Comet Wild 2.
About 15 hours after its closest approach to Earth, the
spacecraft will pass
about 61,000 miles (98,000 kilometers) from the Moon. Because of
the greater
distance, the Moon's gravity will have essentially no influence
on the
spacecraft's flight path.
Stardust, a part of NASA's Discovery Program of low-cost, highly
focused
science missions, is managed by the Jet Propulsion Laboratory
(JPL),
Pasadena, CA, for NASA's Office of Space Science, Washington,
D.C. JPL is a
division of the California Institute of Technology, Pasadena.
More
information on the Stardust mission is available at:
http://stardust.jpl.nasa.gov/index.html
=================
(3) LUNATICS AT WORK: MOON ECLIPSE SPARKS RIOTS BY MUSLIM
FANATICS
From SPACE.com, 10 January 2001
http://www.space.com/scienceastronomy/solarsystem/eclipse_unrest_010110_wg.html
Moon Eclipse Sparks Unrest in Nigerian City
MAIDUGURI, Nigeria (Reuters) -- Rampaging Muslims burned down
scores of
hotels and bars in a northern Nigerian city in reaction to the
lunar eclipse
which they blamed on sinners, residents said on Wednesday.
Paramilitary police battled gangs of Muslim youths in the streets
of the
largely Islamic city of Maiduguri for hours on Tuesday night.
Residents said at least 40 hotels or drinking houses were set
ablaze.
Similar violence was reported in Barma town 50 miles (80
kilometers) away
where youths chanting Allahu Akbar (God is Great) took to the
streets.
"The immoral acts committed in these places are responsible
for this
eclipse," police quoted a youth leader as saying.
Police chief Uba Bala Ringim told Reuters in Maiduguri that five
people had
been detained and more arrests were expected.
Religious violence has been a major problem in the largely
Islamic north
over the past year. Hundreds of people were killed in two bouts
of
Muslim-Christian bloodletting in the northern city of Kaduna over
plans to
introduce Islamic sharia law in the area.
Copyright 2001, Space.com
MODERATOR'S NOTE: The tragicomical events in Nigeria should serve
as a
timely reminder and a warning from history that apocalyptic
scaremongers and
doomsday fanatics (both in the shape of religious *and*
secular/new age
movements) have frequently turned fear-ridden aggressive impulses
into
violence against their opponents whenever an extraordinary cosmic
event was
declared a "threat." If a perfectly harmless spectacle
such as a lunar
eclipse can trigger mob violence, many readers, I am sure, can
imagine what
may happen if, God forbid, an asteroid were ever verified to be
on a
collision course with Earth. Let's not fool ourselves: the impact
hazard is
as much a potential environmental risk as it is a challenge to
societal
order and stability. After all, history has shown time and again
that civil
war, upheaval and genocidal violence lucks behind every
apocalyptic mass
movement. BJP
==============
(4) NASA BALLOON RESEARCH RIDES TO THE EDGE OF SPACE
From Mark Hess <mhess@pop100.gsfc.nasa.gov>
Dolores Beasley
Headquarters, Washington,
DC
January 11, 2001
(Phone: 202-358-1753)
Keith Koehler
Wallops Flight Facility, Wallops Island, VA
(Phone: 757-824-1579)
Betty Flowers
Balloon Launching Station, Alice Springs Airport, Australia
(Phone: 61-8-8952-6315)
RELEASE: 01-03
NASA BALLOON RESEARCH RIDES TO THE EDGE OF SPACE
The countdown is underway for the launch of a revolutionary
research-balloon
designed to fly higher and longer than anything before it, and
the flight
could open a new era in scientific research.
NASA's new Ultra-Long Duration Balloon (ULDB) is scheduled to
lift off Jan.
16 from Alice Springs, Australia, and will carry the hopes of
many
scientists who see balloon technology
as an economical means of studying the Earth and space.
"Although balloons have been flying for more than 200 years
and scientists
have long used them for a variety of research missions, the
length of time
balloons can stay aloft has always constrained their
efforts," said Steve
Smith, Chief of the Balloon Program Office, NASA Goddard Space
Flight
Center's Wallops Flight Facility, Wallops Island, VA.
"Thanks to greatly
enhanced computer technologies, high-tech materials and advanced
designs,
longer-range balloons are poised to open a new frontier for
high-altitude
research".
The balloon is expected to float over the Southern Hemisphere at
an altitude
of approximately 115,000 feet (35 kilometers), 3 to 4 times
higher than
passenger planes. While the test
flight is expected to last only about two weeks and
circumnavigate the
globe, the ULDB is designed to support missions for up to 100
days.
"Balloons provide cost-effective platforms for near-space
observations,"
said Dr. Vernon Jones, Office of Space Science, NASA
Headquarters,
Washington, DC. "This January flight provides an excellent
opportunity to
test the newly designed ULDB system."
The full-scale ULDB is the largest single-cell, super-pressure
(fully
sealed) balloon ever flown. At launch, the balloon is partially
inflated
with helium and expands as it rises. When fully inflated, the
massive ULDB
would barely fit inside a domed football stadium.The ULDB floats
above 99
percent of the Earth's atmosphere and can carry a 3,500-pound
(1.588-kilogram) payload. The balloon system comes down in a
controlled
descent. It may be visible from the ground with a telescope and,
in some
cases, with the naked eye.
The ULDB's unique pumpkin-shaped design and its novel material, a
lightweight polyethylene film about the thickness of ordinary
plastic
food-wrap, were successfully tested during a prototype flight
from Ft.
Sumner, NM, last June.
"Recent development of new balloon materials and associated
technologies
will enable challenging, important investigations to be done at
relatively
modest cost," said Jones. He added that the ability to fly
balloons for
months or years at a time would create a multitude of scientific
and
business opportunities.
Conventional high-altitude, scientific balloon flights typically
last a few
days to a week because temperature changes from day to night
ultimately
cause the balloon to lose altitude. The ULDB is completely
sealed, so gas is
not vented to relieve pressure. The new super-pressure balloon
will maintain
lift, size and shape, and will not lose significant altitude due
to
atmospheric influences.
Future science missions for the ULDB will study the source of
cosmic rays
generated from shock waves emanating from supernovae and will
perform
surveys of X-ray emiting objects in the universe, search for
planets around
other nearby stars and will study other objects in space,
including the Sun.
The Wallops Flight Facility manages NASA's scientific balloon
program for
the Office of Space Science. Launch operations are conducted by
the National
Scientific Balloon Facility, Palestine, TX, which is managed for
NASA by the
Physical Sciences Laboratory of New Mexico State University, Las
Cruces.
Australian operational support to NASA is provided by the
Commonwealth
Scientific Industrial Research Organization.
More information on the Ultra-Long Duration Balloon mission and
tracking of
the balloon flight can be found at:
http://www.wff.nasa.gov/pages/scientificballoons.html
============================
* LETTERS TO THE MODERATOR *
============================
(5) COMA BERENICIDS, YES; COMET CONNECTIONS, NO
From Brian Marsden <brian@cfaps1.harvard.edu>
Dear Benny,
I was quite startled to read in the Jan. 11 CCNet, not only of
the suggested
association of a recently observed meteor shower with "the
poorly observed
Comet Lowe 1913 I", but also of the suggested identity of
the 1913 object
with another comet, "observed, again rather badly, in
1750".
The fact is that the 1913 object was recorded only by its
discoverer, an
"enthusiastic" Australian amateur astronomer, who on
Jan. 7 of that year
reported to the Adelaide Observatory _very_ rough (and initially
quite
erroneous) positional data obtained by him with a 3-inch
telescope on four
mornings during the previous week. Even when the data were
amended and
attempts made to compute an orbit, no observations by others came
to light,
which was a little surprising since the object should have been
an easy
object for northern-hemisphere astronomers at and before its
alleged
discovery. This situation is reminiscent of many that continue to
arise at
the IAU Central Bureau for Astronomical Telegrams, and perusal of
the Lowe
information preserved in the Astronomische Nachrichten and the
Journal of the British
Astronomical Association cannot help but place the existence of
the object
in doubt. Although the various orbits computed at the time by
Viljev and
Crommelin agreed on a nodal longitude of 300 to 305 degrees (and
the
possibility of a very close approach to the earth around Jan. 25
if the
comet had come to perihelion some weeks later than indicated),
there was
disagreement as to whether the orbital inclination was 80 degrees
or 120
degrees: if I wish to contend with residuals of well over a
degree, I get an
inclination of something like 110 degrees. Nevertheless, as
stated in the
introduction to the Catalogue of Cometary Orbits already in the
1972
edition, I felt it wise to exclude this comet from consideration,
and it was
not given a new-style designation when the comet-designation
system was
revised at the end of 1994.
What about the comet of 1750? The positional information was also
provided
by just a single observer, who saw the comet on three nights in
January of
that year. In this case the recorder was the distinguished
astronomer and
demographer and secretary of the Royal Swedish Academy of
Sciences, Pehr Wargentin. The observations were made with the
naked eye and
two different telescopes, and the comet was also seen by a
colleague. Given
that this was in the days before comet hunting became a sport
(with comets
named for their discoverers), I have little doubt that the object
existed
and discussed it in my paper in the Astronomical Journal in 1973
on the
orbit of the comet associated with the Perseid meteors.
Interestingly, the
nodal longitude is also around 300 degrees, and the inclination
could be as
low as 120 degrees. The orbit I actually published does in fact
bear a
superficial resemblance to some computed from Lowe's 1913 data,
although the
published perihelion distance, 0.2 AU, is only half that derived
in 1913.
Furthermore--as I actually remarked in my paper--if the 1750
perihelion
distance were as large as 0.4 AU, the argument of perihelion
would drop to
240 degrees, which is significantly less than the 280-degree
value that best
fits the 1913 data.
Even if one accepts the reality of the 1913 data, there is no
reason to
believe that the comet had a period as short as a century or two,
and there
is in any case no way to satisfy both apparitions of data with
the same
orbit. Given my predilection for the reality of the 1750 comet,
one might
wish to consider it a better candidate for the parent of the Coma
Berenicid
meteors. But it does not seem that the orbit of the 1750
comet comes particularly
close to the earth. Although the date was close to the
anticipated previous
perihelion passage of the 1862 parent of the Perseid meteors,
Wargentin's
comet was clearly not it. My acceptance instead of Kegler's 1737
comet as "a
far better candidate" and consequent prediction of the
late-1992 return was
of course later amply demonstrated.
So while I give Gorelli and McBeath credit for attempting a
meteor-comet
association, the least said about the 1913 and the 1750 events,
the better.
Regards
Brian
===============
(6) EARTH IS THE MOST LIKELY PLACE FOR LIFE'S ORIGIN IN OUR SOLAR
SYSTEM
From Steve Drury <s.a.drury@open.ac.uk>
Benny,
I don't want to make a meal of this, but the most likely place
for life to
start up in the Solar System has always been the Earth, because
of its
proximity to the Sun and its high content of volatiles, including
water. A
cooler Sun in the appropriate period (4500 to 3600 million years
ago)
narrows the focus to Earth and possibly Venus even more.
Indeed, for the
pre 3600 million-year Earth, it is necessary to postulate an
atmosphere with a strong
"greenhouse" effect for liquid water to exist at the
surface (we know from
water transported sediments from Greenland that such conditions
did exist
here on a permanent basis at around 3800-4000 million years
ago). The
"cool, young Sun" constraint applies even more
stringently for Mars, except
during periods of bombardment.
What seems to be overlooked in the speculation about panspermia
and the
possibility of former life on Mars as its source, is that any (as
yet
undiscovered)bio-materials shifted from planet to planet by
debris from
impacts are a great deal more likely to have come from Earth than
anywhere
else.
That is made even more probable by the Earth's greater
gravitational cross
section, and its increased likelihood of being bombarded by
projectiles of a
suitable size to achieve that.
Since the heaviest terrestrial bombardment took place around 4000
to 3800
Ma, when living processes almost certainly had taken a hold on
Earth, that
is the period when such an outward delivery might have taken
place.
Steve Drury
Earth Sciences
Open University
UK
================
(7) GRANDE CHALLENGE: A PRAGMATIC APPROACH TO DISASTER PREVENTION
&
MANAGEMENT
From Andy Smith <astrosafe@yahoo.com>
Hello Benny and CCNet,
Congratulations on the four successful years of CCNet
publication. This well
organized and presented open-forum is helping us...the people of
this fine
planet... to rally to our own defense and to discuss and to plan
to
successfully meet the Grande Challenge....and it is certainly
appropriate
for us to do this.
Our toil to prevent the next impact is as much a test of
ourselves, as it is
a test of our technology. We cannot win this ultimate contest
unless we are
finally able to work togeather and to share what we know.
We are very
optimistic, here in New Mexico, and we think humanity can pass
this great
test.
Early-Warning Progress
We made it. For the first time, the global asteroid/comet hunting
community
found one new NEO per
day....and this is the third year of 3-digit NEO discovery. The
discoveries
in these three years have more than doubled all of the other NEO
finds, in
the last 100 years.
About a third of the discoveries were a kilometer or more, wide.
LINEAR
found about 71% of the total. LONEOS was second, with about 10%
and
SPACEWATCH was third, with about 7%.
The next goal is to reach the four digit level, annually. The MPC
credited
ten sites and teams with the recent discoveries and it would seem
this group
could get us to that next level....and they will certainly have
help from
several new programs (including the excellent new facility in
Japan). Even
at 3,000 NEO discoveries per year, it will take decades to find
the 100,000
or so space bombs (bigger than Tunguska) which we need to
identify and
track.
We congratulate and thank all who have contributed to the
tremendous
progress which has been made, in NEO discovery, and we wish them
a great
hunting year.
Defense Progress
Recent developments in asteroid/comet spacecraft design and
testing are also
very encouraging
(NEAR/EROS, etc.) and the studies of deflection technology,
conducted by the
Russian institutions, are clearly pointing-the-way to the first
generation
of interception/deflection systems.
We are strongly encouraging the conduct of all of the engineering
studies
needed to permit a rapid emergency deployment (few months or
weeks from
alarm-to-launch, instead of years).
International Communications
Thanks to the CCNet, we are starting to have some very productive
exchanges
of ideas and information and the content contributions, by
Michael Paine and
many others, are helping, tremendously.
We want to encourage efforts to provide translations of CCNet, if
possible,
on the Web and we urge both the Spaceguard and Space Shield
Foundations to
promote more open dialogue. We also want to encourage the
Planetary Society
to continue to promote information exchange.
Civil Emergency Preparedness
We plan to continue to encourage both FEMA and the coastal cities
to develop
emergency tsunami evacuation plans and we invite all who want to
help to
contact us. The guidelines we are developing include quick exodus
public
training, with maps and marked routes. Some planning has started,
in the
Pacific, but the Atlantic coastal cities are still largely
unprepared. With
help from FEMA, the media and the State and local emergency
preparedness
organizations, we might save
millions of lives, with such planning and training.
Governmental Support
We cheer our colleagues, in the United Kingdom, for the progress
they made,
last year, in getting this important issue before their
government and we
hope a good program will result.
Asteroid Winter (AW) Emergency Food
We are also beginning to look at the kinds of things we could do
to feed
ourselves, during an AW. The extinction survivors are the good
scavengers.
We are looking at the compounding of synthetic foods, ways to
significantly
increase both national and family emergency provisioning -
especially with
dried grains and beans and at ways to farm, in low-light and
temperature
environments. We invite more dialogue, in this area.
We are also drafting a legislative proposal which is aimed at
increasing the
national emergency food reserve, in the U.S., and we are
encouraging similar
efforts, in other countries.
Asteroid/Comet and Planetary Defense Sessions for the
International Space
Development Conference (ISDC 2001), May 2001 and SPACE 2001,
August 2001.
We are still accepting abstracts for SPACE 2001. Both meetings
will be
hosted in Albuquerque and both now have good Web pages. Please
join us, if
you can. We will also summarize the presentations and
discussions, on the
CCNet.`
Cheers
Andy Smith
============
* ABSTRACTS *
============
(8) FORMATION OF IRON METEORITES
Benedix GK, McCoy TJ, Keil K, Love SG: A petrologic study of the
IAB iron
meteorites: Constraints on the formation of the IAB-Winonaite
parent body
METEORITICS & PLANETARY SCIENCE 35: (6) 1127-1141 NOV 2000
We studied 26 IAB iron meteorites containing silicate-bearing
inclusions to
better constrain the many diverse hypotheses for the formation of
this
complex group. These meteorites contain inclusions that fall
broadly into
five types: (1) sulfide-rich, composed primarily of troilite and
containing
abundant embedded silicates; (2) nonchondritic, silicate-rich,
comprised of
basaltic, troctolitic, and peridotitic mineralogies; (3) angular,
chondritic
silicate-rich, the most common type, with approximately
chondritic
mineralogy and most closely resembling the winonaites in
composition and
texture; (4) rounded, often graphite-rich assemblages that
sometimes contain
silicates; and (5) phosphate-bearing inclusions with phosphates
generally
found in contact with the metallic host. Similarities in
mineralogy and
mineral and O-isotopic compositions suggest that IAB iron and
winonaite
meteorites are from the same parent body.
We propose a hypothesis for the origin of IAB iron meteorites
that combines
some aspects of previous formation models for these meteorites.
We suggest
that the precursor parent body was chondritic, although unlike
any known
chondrite group. Metamorphism, partial melting,and incomplete
differentiation (i.e., incomplete separation of melt from
residue) produced
metallic, sulfide-rich and silicate partial melts (portions of
which may
have crystallized prior to the mixing event), as well as
metamorphosed
chondritic materials and residues. Catastrophic impact breakup
and
reassembly of the debris while near the peak temperature mixed
materials
from various depths into the re-accreted parent body. Thus,
molten metal
from depth was mixed with near-surface silicate rock, resulting
in the
formation of silicate-rich IAB iron and winonaite meteorites.
Results of
smoothed particle hydrodynamic model calculations support the
feasibility of
such a mixing mechanism. Not all of the metal melt bodies were
mixed with
silicate materials during this impact and reaccretion event, and
these are
now represented by silicate-free IAB iron meteorites. Ages of
silicate
inclusions and winonaites of 4.40-4.54 Ga indicate this entire
process
occurred early in solar system history.
Addresses:
Benedix GK, Virginia Tech, Dept Geol Sci, Blacksburg, VA 24061
USA.
Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA.
Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci,
Washington, DC
20560 USA.
NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol,
Hawaii Inst Geophys &
Planetol, Honolulu, HI 96822 USA.
Hawaii Ctr Volcanol, Honolulu, HI USA.
Copyright © 2001 Institute for Scientific Information
==============
(9) ACTIVE REGIONS ON THE SURFACE OF COMET 43P/WOLF-HARRINGTON
Szutowicz S: Active regions on the surface of Comet
43P/Wolf-Harrington
determined from its nongravitational effects
ASTRONOMY AND ASTROPHYSICS 363: (1) 323-334 NOV 2000
The nongravitational perturbations in the motion of the periodic
comet
Wolf-Harrington are investigated during its nine observable
apparitions in
the period 1924-1998. To explain the irregular variations in the
nongravitational acceleration, two different models are
considered and
successfully used to link all the apparitions: a) Model of
nucleus with the
activation and deactivation of discrete outgassing sources on the
surface;
b) Forced precession model of the spin axis of the nucleus with
an activity
described by nonlinear changes of the perihelion shift of the gas
production
curve. The first model is represented by two slightly different
orbital
solutions in which the northern active region is persistent and
the
initiations and disappearances of two southern regions are
responsible for
the observed variability of the nongravitational acceleration.
Profiles of
the modelled gas production rates are compared with observed
light curves of
the comet and used for an estimation of the effective outgassing
area and
the activity level of the cometary nucleus. According to all
employed models
of the nongravitational acceleration similar shifts of the
maximum of the
comet activity with respect to successive perihelion passages
over the whole
examined interval of the motion have been detected.
The model parameters describing physical properties of the comet
nucleus
such as the nucleus orientation, the localization and the size of
the active
regions or the oblateness of the nucleus are derived from
numerical fitting
of the models to positional observations of the comet.
Addresses:
Szutowicz S, Polish Acad Sci, Space Res Ctr, Bartycka 18A,
PL-01237 Warsaw,
Poland.
Polish Acad Sci, Space Res Ctr, PL-01237 Warsaw, Poland.
Copyright © 2001 Institute for Scientific Information
===============
(10) POSITIONAL ERRORS & THE PERTURBED TWO-BODY PROBLEM
Arakida H, Fukushima T: Long-term integration error of
Kustaanheimo-Stiefel
regularized orbital motion
ASTRONOMICAL JOURNAL 120: (6) 3333-3339 DEC 2000
We confirm that the positional error of a perturbed two-body
problem
expressed in the Kustaanheimo-Stiefel (K-S) variable is
proportional to the
fictitious time s, which is the independent variable in the K-S
transformation. This property does not depend on the type of
perturbation,
on the integrator used, or on the initial conditions, including
the nominal
eccentricity. The error growth of the physical time evolution and
the Kepler
energy is proportional to s if the perturbed harmonic oscillator
part of the
equation of motion is integrated by a time-symmetric integration
formula,
such as the leapfrog or the symmetric multistep method, and is
proportional
to s(2) when using traditional integrators, such as the
Runge-Kutta, Adams,
Stormer, and extrapolation methods. Also, we discovered that the
K-S
regularization avoids the step size resonance/instability of the
symmetric
multistep method that appears in the unregularized cases.
Therefore, the K-S
regularized equation of motion is useful to investigate the
long-term
behavior of perturbed two-body problems, namely, those used for
studying the
dynamics of comets, minor planets, the Moon, and other natural
and
artificial satellites.
Addresses:
Arakida H, Grad Univ Adv Studies, Dept Astron Sci, 2-21-1 Osawa,
Mitaka,
Tokyo 1818588, Japan.
Grad Univ Adv Studies, Dept Astron Sci, Mitaka, Tokyo 1818588,
Japan.
Natl Astron Observ, Tokyo 1818588, Japan.
Copyright © 2001 Institute for Scientific Information
=================
(11) ASTEROIDAL PROCESSING OF CHONDRITIC MATERIALS
Bland PA, Lee MR, Sexton AS, Franchi IA, Fallick AET, Miller MF,
Cadogan JM,
Berry FJ, Pillinger CT: Aqueous alteration without a pronounced
oxygen-isotopic shift: Implications for the asteroidal processing
of
chondritic materials
METEORITICS & PLANETARY SCIENCE 35: (6) 1387-1395 NOV 2000
Primitive meteorites exhibit certain features that are consistent
with
aqueous and thermal alteration on asteroids, but O-isotopic
analyses show
only a modest heavy-isotope shift, interpreted as indicating
modification in
the nebula. To understand the isotopic effects of asteroidal
alteration, we
take the L-group ordinary chondrites weathered in Antarctica as
an analogue.
The data show that alteration is a two-stage process, with an
initial phase
producing only a negligible isotopic effect. Although surprising,
a possible
explanation is found when we consider the alteration of
terrestrial
silicates. Numerous studies report pervasive development of
channels a few
to a few tens of nanometer wide in the incipient alteration of
silicates. We
observe a similar texture. Alteration involves a restructuring of
clay
minerals along these narrow channels, in which access of water is
restricted. The clay shows a topotactic relationship to the
primary grain,
which suggests either epitaxial growth of the clay using the
silicate as a
substrate or inheritance of the original O structure by the clay.
Our data
suggests the latter: with extensive inheritance of structural
polymers by
the weathering product, the bulk O-isotopic composition is
comparatively
unaffected. This offers an explanation for the lack of an
isotopic effect in
the weathering of the L chondrites. If substantial modification
of
chondritic materials may occur without a pronounced isotopic
effect, it also
reconciles existing O analyses of CV chondrites with an
asteroidal model of
aqueous alteration.
Addresses:
Bland PA, Nat Hist Museum, Dept Mineral, Cromwell Rd, London SW7
5BD,
England.
Nat Hist Museum, Dept Mineral, London SW7 5BD, England.
Univ Edinburgh, Dept Geol & Geophys, Edinburgh EH9 3JW,
Midlothian,
Scotland.
Open Univ, Planetary Sci Res Inst, Milton Keynes MK7 6AA, Bucks,
England.
Scottish Univ Res & Reactor Ctr, Glasgow G75 0QF, Lanark,
Scotland.
Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia.
Open Univ, Dept Chem, Milton Keynes MK7 6AA, Bucks, England.
Copyright © 2001 Institute for Scientific Information
================
(12) INTERNATIONAL INSTITUTIONS AND THE MANAGEMENT OF GLOBAL
RISKS
Haas PM: International institutions and social learning in the
management of
global environmental risks
POLICY STUDIES JOURNAL 28: (3) 558-575 2000
This article investigates the role played by formal international
institutions in the broader process of international efforts to
respond to
and manage global and transboundary environmental risks. Because
few
international institutions are designed to deal with the broad
nature of
environmental risks, it focuses on institutional learning. By
analyzing the
experiences of the United Nations Environment Program, World
Meteorological
Organization, and other international institutions involved with
global
warming, this article identifies institutional properties (or
functions)
that encourage or inhibit social learning in the management of
global
environmental risks by international institutions, and that
influence the
adoption of such lessons by their constituent members.
Addresses:
Haas PM, Univ Massachusetts, Amherst, MA 01003 USA.
Univ Massachusetts, Amherst, MA 01003 USA.
Copyright © 2001 Institute for Scientific Information
==============
(13) AND FIMALLY: SPACE RESAERCH SPILLS ZE END FOR DYSLEXIA
From The Scotsman, 12 January 2001
http://www.thescotsman.co.uk/uk.cfm?id=38724&keyword=the
Jennifer Trueland Health Correspondent
DYSLEXIA could be eradicated within a decade for most children
using
exercises developed for disorientated spacemen returning to
earth, British
experts said yesterday.
A private clinic in Warwickshire has harnessed discoveries made
by the US
space administration NASA to help affected children improve their
reading
and writing ability.
Initial results of a study into the exercise method are to be
presented at a
conference held by the British Dyslexia Association in York in
April.
NASA had found that astronauts suffered a kind of temporary
dyslexia,
thought to be caused by weightlessness, which disrupts the way
the
connections between their brain and actual functions. To help the
astronauts, they developed a balance and measurement machine and
exercises
to retrain the eyes to track smoothly and the brain to listen to
the body's
balance mechanisms.
The programme is now being pioneered at the Dyslexia, Dyspraxia
and
Attention Treatment Centre (DdAT) in Kenilworth, which is funded
by Wynford
Dore, whose own daughter, Susie, suffered from dyslexia.
His programme is based on work conducted by Professor Rod
Nicholson and
Angela Fawcett at the University of Sheffield which focuses upon
the area of
the brain which manages co-ordination.
The British clinic uses one of the £100,000 NASA machines to
screen children
with dyslexia and prescribe individual exercise programmes at a
cost of
about £475.
According to Mr Dore, the clinic has shown results no one could
have dreamt
of, with 97 per cent of children showing significant improvement
within
three months.
"I hope that within ten years every child starting school
will be screened
and treated so that they can go through school without the stigma
and
difficulties they suffer at the moment.
"I think every child who has been through the programme has
shown some
improvement and adults too, who have tried it have found an
explanation why
they have always found some things difficult. It's like a sigh of
relief for
adults and for children it's the chance to ride a bike, catch a
ball and do
all the other things that they want to do."
The programmes work on posture, balance and eye control.
Exercises include
encouraging children to recite a times table while standing
one-legged on a
cushion and throwing a bean bag from one hand to the other at eye
level.
A formal research programme to evaluate the technique's success
will be
started this month, overseen by Professor David Reynolds of
Exeter
University.
He said: "Best-case scenario is that there's a powerful
treatment effect
which could live up to the claim that it will eradicate dyslexia
within ten
years. But we need the scientific evidence to back the
impressionistic
evidence that there appears to be something there."
He said the clinic had already treated more than 90 children.
Copyright 2001, The Scotsman
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