PLEASE NOTE:
*
CCNet, 4 November 1999
------------------------------
QUOTES OF THE DAY
"Previous estimates of fatality and
damage rates on the 100 to
10,000 year time scale are shown to be
too low because they
neglect rare, highly lethal outriders of
the populations of
bombarding objets, those with
exceptional strength, unusually low
entry velocity, and near-horizontal
entry angles."
-- John S.
Lewis, Comet and Asteroid Impact Hazards on a
Populated Earth, Academic Press Inc, 1999
"In essence, I fancy Earth
protection as an evolution of the
function that national defense has
held--attempting to minimize
danger to citizenry while maintaining a
status quo. Obviously
this is a social, philosophical, and
funding issue; the question
is whether resources will continue to
flow most readily to
short-term money-making projects or to
endeavors that can enhance
real wealth, which is accurate knowledge
of how our world works.
Perhaps increasing evidence of rapid
climate change may help to
tip various tills toward survival
enhancement."
-- Bob Kobres, 3 November 1999
(1) LEONID METEORITE IMPACTS ON MOON MAY BE VISIBLE ON EARTH
Ron Baalke <baalke@ssd.jpl.nasa.gov>
(2) AIR FORCE, NASA TO OBSERVE LEONID METEOR STORM
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) NEAR-LIVE LEONID WATCHING SYSTEM
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(4) ABRUPT CLIMATE CHANGE & SPACEGUARD
Bob Kobres <bkobres@arches.uga.edu>
(5) ASTEROID IMPACT HAZARDS ON A POPULATED EARTH
New book by John S. Lewis (1999), Academic
Press Inc
(6) ORBFIT 2.0
Andrea Milani <milani@lagrange.dm.unipi.it>
(7) EARTH-IMPACTING SUN STORMS PREDICTED
Andrew Yee <ayee@nova.astro.utoronto.ca>
(8) ASTRONOMERS FIND EVIDENCE OF FIRST PLANET ORBITING A PAIR OF
STARS
NASANews@hq.nasa.gov
===============
(1) LEONID METEORITE IMPACTS ON MOON MAY BE VISIBLE ON EARTH
From Ron Baalke <baalke@ssd.jpl.nasa.gov>
Leonids on the Moon
Marshall Space Flight Center
http://science.nasa.gov/newhome/headlines/ast03nov99_1.htm
Leonid meteorite impacts on the Moon might be visible from Earth
and
provide a means for long-distance lunar prospecting.
Nov. 3, 1999: When the Leonid meteor shower strikes on the
morning of
November 18, 1999, our planet won't be the only place in the
cross
hairs. The Moon will also pass very close to the debris stream of
comet
Tempel-Tuttle. Here on Earth, space-borne meteoroids will plummet
into
the atmosphere and burn up, creating streaks of light called
meteors.
The vast majority of meteoroids will burn and disintegrate well
before
they hit the ground. The situation on the Moon, where there is no
appreciable atmosphere, is different. Every bit of comet debris
that
rains down on our satellite will hit its surface. Some meteor
enthusiasts hope that will create a different sort of display.
Rather
than streaks of light in lunar skies, there could be flashes of
light
on the Moon's surface each time a sizable meteoroid hits the
ground.
Last year, during the 1998 Leonid meteor shower, the phase of the
moon was new. It was so close to the sun in the sky that
observing
faint lunar meteorite flashes was impossible. This year is
different.
During the 1999 Leonid shower the phase of the Moon will be just
2
days past first quarter. That means the moon will visible in the
night sky during the early evening on November 17, and
approximately
35% of the lunar disk as seen from Earth will not be illuminated
by
sunlight. There will be plenty of dark lunar terrain where
flashes
might be visible.
Is it possible to observe such flashes?
Maybe, say researchers. It depends a great deal on the mass
spectrum
of particles in the Tempel-Tuttle debris stream and how
efficiently
kinetic energy is converted into optical light as a result of the
impacts. Both factors are poorly known. Although flashes are
unlikely
to be seen with the naked eye, they may be detectable through
amateur
telescopes.
"The impact of a one gram particle would generate of the
order of
1023 to 1024 photons in the peak sensitivity range of the human
eye,"
says Dr. Bo Gustafson of the University of Florida Laboratory for
Astrophysics. "Given the distance to the Moon, we could
expect a few
times 106 photons per square meter at the Earth. This should be
barely detectable using a small telescope."
In June 1999, Ciel & Espace reported that a Spanish team of
astronomers led by J.L. Ortiz had reached similar conclusions:
Watching meteorites fall on the moon ...
is within reach of
(modest) amateur telescopes. Because the
Moon doesn't have a
substantial atmosphere, meteorite
impacts there are much more
violent than here on Earth liberating
much more energy: 20 million
joules for a 1-kg block. As seen from
the Earth, this would
produce a flash of magnitude 9 to 15.
From Ciel & Espace, No. 349
- Juin 1999, p. 17: Si, c'est possible!
(Translation courtesy
Bernd Pauli HD).
"The Leonid debris stream is in a retrograde orbit, and it's
inclined
just 22 degrees from the plane of Earth's orbit around the
sun," says
Professor George Lebo of the University of Florida Department of
Astronomy. "That's why the Leonids enter the atmosphere with
such a
high velocity [72 km/s]. The Earth and the Leonids hit head-on,
like
a head-on collision between two speeding automobiles."
"If you put yourself in the reference frame of the Earth
it's pretty
easy to figure out where these meteoroids will hit the Moon,
"continued Lebo. "On November 18, at 0h UT the lunar
sub-Leonid point
[the spot where Leonid meteoroids rain directly down on the
Moon's
surface] will be 9.4 degrees north of the lunar equator and 9.5
degrees sun ward of the day-night terminator. In other words, the
greatest flux of Leonids are going to hit nearly dead center on
the
lunar disk as seen from Earth, just over the terminator on the
sunlit
side."
It won't be possible to see flashes on the Moon's sunlit surface,
so
amateurs will have to look where the terrain is dark. The best
approach will be to train a telescope -- higher powers are best
for
discerning faint flashes -- at a spot near the lunar equator on
the
night side of the terminator, keeping the sunlit side of the moon
completely out of the field of view. Flashes observed with the
naked
eye would certainly be exciting, but might have little scientific
value. Instead, experienced observers suggest using a low-light
astronomical CCD video camera to make a permanent record.
The Leonids radiant, in the constellation Leo, rises above the
horizon at mid-northern latitudes around midnight on November
17/18.
That's about the same time that the Moon sets. It's an ideal
situation for observers who can monitor the Moon for the first
half
of the night and then enjoy the Leonid meteor shower from
midnight
until dawn.
Leonid Lunar Prospecting
Although optical flashes were not observed on the moon during
last
year's meteor shower, a team of scientists from the Boston
University
Center for Space Physics discovered indirect evidence for Leonid
impacts.
The Moon has an extremely tenuous atmosphere that contains, among
other things, sodium atoms. Just above the Moon's surface the
density
of sodium is 50 atoms per cubic centimeter. For comparison, the
sodium density in Earth's lower atmosphere is 1019/cc! Although
the
Moon's atmosphere is incredibly thin, researchers at Boston
University's space physics lab have built sensitive cameras that
can
trace its sodium component out to several lunar radii.
In mid-November 1998 the Boston University group were using their
sodium camera to monitor Earth's atmosphere for changes due to
Leonid
meteors. To their surprise they detected a bright sodium spot on
November 17 that grew in brightness, peaked on November 19, and
then
faded away. The spot was almost 180 degrees away from the new
Moon in
the night sky. Nevertheless, the source of the sodium was
apparently
Earth's satellite. When Leonid meteoroids crashed into the Moon's
dusty soil they kicked up an extra helping of sodium atoms,
increasing the density of the Moon's thin atmosphere. A long
lunar
sodium tail formed (much like the tail of a comet) which swept by
our
planet two days later.
The Boston University experiment showed for the first time that
intense meteor showers might be one way of "lunar
prospecting" from a
distance -- by looking at materials blasted off the surface as
meteoroids strike. A team of scientists from the University of
Texas
and NASA tried something similar earlier this year when they
crashed
NASA's Lunar Prospector spacecraft into the Moon. The probe was
sent
hurtling into a south polar crater on July 31 in hopes that the
impact would vaporize shadowed water-ice and send a cloud of
water
vapor and OH flying over the lunar limb. Telescopes, including
the
Hubble Space Telescope, looked near the impact site after the
crash,
but failed to detect evidence for water. That doesn't mean
there's no
water on the moon, say scientists. Lunar Prospector may simply
have
hit a dry spot, or perhaps the water vapor didn't rise high
enough to
see.
Dr. David Goldstein, a professor at the University of Texas who
proposed the Lunar Prospector impact experiment, is wondering if
the
Leonids might succeed where the Lunar Prospector crash failed.
Data
from Lunar Prospector's neutron spectrometer indicate that
water-ice
on the moon is concentrated around the Moon's poles where
shadowed
areas would allow pockets of water to remain frozen (see the
figure
below). The 1999 Leonids won't reach the Moon's south pole, but
many
meteoroids should strike the north pole.
"The Leonids will be coming in from above the ecliptic
plane," says
Goldstein. "Given the Earth-moon geometry on November 18th
that means
that the lunar north pole will be exposed, but not the south
pole.
That's unfortunate because there's thought to be more water
around
the south pole where we crashed Lunar Prospector. There's no
chance
of a Leonid meteoroid hitting the crater where Prospector
crashed.
Near the north pole the meteoroids will be coming in at several
degrees above the horizon -- very similar to the Lunar Prospector
trajectory."
"Compared to Lunar Prospector, Leonid meteoroids are light
weight and
tiny, but they move a lot faster," Goldstein continued.
"The mass of
Lunar Prospector was 160 kg and it was moving 1.7 km/s when it
hit
the moon on July 31. Leonid particles are going about 72 km/s.
That
means that a Leonid the mass of a golf ball (about 0.1 kg) would
deliver the same kinetic energy as the Lunar Prospector
crash."
"If a Leonid meteoroid did hit a spot near the north pole
with frozen
water, it's not clear what we would see. The Lunar Prospector
collision was like a car crash -- it was moving at relatively
slow
speed. When it hit, we hoped it would kick up water vapor that
would
be dissociated into OH by ultraviolet sunlight. In theory we
would
then see the OH by looking above the sunlit lunar limb with
appropriate spectrometers. A Leonid crash would be much more
violent.
Instead of water vapor gently wafting above the lunar limb, we
might
see ionized, hot plasma. It's possible that we would also get
some
warm water vapor that didn't sustain such a damaging shock wave,
but
it's really hard to say. We haven't done the high speed
simulations yet."
Goldstein says that he and his colleagues may not have time to
organize a search for signs of water kicked up by Leonids this
year,
following so closely on the heels of the Lunar Prospector
experiment.
However, with some experts predicting significant Leonid activity
into the next millennium, there will be time to arrange an
observing
campaign for next year and beyond.
=============
(2) AIR FORCE, NASA TO OBSERVE LEONID METEOR STORM
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Air Force Space Command News Service
Released: 3 Nov 1999
Air Force, NASA to observe 1999 Leonid meteor storm
PETERSON AIR FORCE BASE, Colo. (AFPN) -- The Air Force and NASA
are
teaming with the international scientific community to monitor
November's rare and potentially hazardous Leonid meteor storm.
The Earth is scheduled to pass through the debris stream from the
comet
Tempel-Tuttle Nov. 17 and 18. The collision of this debris with
the
Earth's atmosphere could produce a spectacular display of
hundreds to
thousands of meteors per hour. The Leonid shower hits its peak
every 33
years.
The University of Western Ontario, the Canadian Space Agency,
Canada's
Department of National Defence, and the European Space Agency are
teaming with NASA and the Air Force to set up monitoring sites at
seven
locations around the world.
Special electro-optical video equipment will be set up at sites
in
Hawaii, Florida, the Canary Islands, Kwajalein Atoll in the
Marshall
Islands and at two sites in the Negev Desert, Israel, to record
the
storm as it develops. The data collected from these seven sites
will be
transferred to a communications center at NASA's Marshall Space
Flight
Center in Huntsville, Alabama. From Alabama, NASA and UWO
researchers
will compile and profile the data so satellite operators can
access it.
The monitoring sites were chosen because they lie along what is
expected to be the best longitude for viewing. The storm is
predicted
to peak Nov. 17.
=============
(3) NEAR-LIVE LEONID WATCHING SYSTEM
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
Forwarded from George Varros (gvarros@mail.hq.nasa.gov)
Subject: Near-Live Leonid Watching System
In anticipation of "higher than normal" meteor activity
during this
November's annual Leonid Meteor Shower, NASA has created an image
library and invites amateur astronomers, photographers and
individuals
with Single Lens Reflex (SLR) cameras or other imaging equipment,
to upload their Leonid meteor photographs or images to the
Near-Live
Leonid Meteor Watching System.
http://leonids.hq.nasa.gov/
A Brief Background on the Leonid Meteors:
Every 33 years, there is a higher probability that the Leonid
Meteor
Shower will turn into a meteor storm. This is caused by the
parent
comet 55P/Temple-Tuttle and its 33 year orbit around the sun,
which
nearly intersects that of Earth's. Fortunately, this occurs with
Earth
and the comet on different sides of Earth's orbit.
As it approaches the inner solar system and is heated by the sun,
the
comet replenishes its path with tiny bits of material eroded away
by
the solar wind and radiation. As Earth travels in its path around
the
sun and encounters this debris stream, the small grains of
material in
this stream slam into Earth's upper atmosphere at a very high
rate of
speed becoming incandescent and leaving an ionized and luminous
trail
that we see as meteor or "falling star".
On an average year, 15 to 20 Leonid meteors per hour can be seen,
depending on your local viewing conditions. During a storm year,
anything can happen as history has shown. The last major Leonid
Meteor
Storm occurred on November 16, 1966, peaking for observers in the
mid-western United States. Hourly meteor rates were estimated to
be as
high as 144,000! Historical accounts dating back to the 1833 and
1866
Leonids are fascinating to read! The 1899 and 1932 Leonids were
largely
missed and it is suspected that Jupiter may have altered the
meteor
stream's orbit for those years. Studies also suggest 2000,
2001 or
even 2002 could be much better than normal years, with
significantly
higher meteor counts than normal years! The 1999 Leonid Meteor
Shower
is an event that has been long anticipated by the astronomy
community.
Predictions:
The peak of the meteor shower or "storm component" has
been predicted
by the experts to interact with Earth some time between 01:48 and
04:15
Universal Time, November 18, 1999. Observable hourly rates should
be
significantly higher than normal years, perhaps on the order of
several
hundred to several thousand per hour during the peak. However, it
must
be emphasized that the various components of a meteor shower,
such as
peak time and hourly rates are extremely hard to predict.
The peak
time can be off by several hours and recorded counts will
certainly
vary with local sky conditions, the moon and light pollution,
visual
obstructions and location on Earth.
If the peak occurs during the earlier predicted time, Asia and
Europe
will be positioned favorably with the radiant high overhead. If
it
occurs a few hours past the later predicted time, the western
portions
of Europe and Africa, along with the East Coast of the United
States,
will be positioned favorably. This is certainly an event not to
be
missed and it would be well advised to look for the Leonids
during the
early morning hours of November 17th and November 19th, due to
the
uncertainty.
A Scenario For US East Coast Observers:
The radiant or apparent area of origin of the meteors, in the
constellation Leo, rises in the east shortly before midnight
local time
November 17th (November 18, 1999 05:00 Universal Time). No Leonid
meteors should be expected to be seen prior to this due to the
direction that the meteors travel. The moon will interfere with
meteor
visibility shortly after the radiant rises. It will be waxing
gibbous
or just past half full and will be setting around 1:00AM local
time.
It should be noted that the radiant does rise just after the
predicted
peak for US East Coast observers. However, if the peak, which is
very
hard to predict is a few hours late, the US will be able to
observe the
peak with the radiant higher in the sky!
George Varros
=============
(4) ABRUPT CLIMATE CHANGE & SPACEGUARD
From Bob Kobres <bkobres@arches.uga.edu>
Hi Benny
Regarding abrupt climate change and the Younger Dryas climate
crisis:
An interesting site that I had not seen in past queries has been
put
together by William H. Calvin of the University of Washington in
Seattle:
http://williamcalvin.com/bookshelf/climate.htm
Calvin goes into how human evolution might have been affected by
such
changes as well as speculative ways that certain rapid changes
(NADW
induced) might be mitigated.
The one thing that I have found a bit disturbing about the notion
of
'Spaceguard' is the tendency to define this project exclusively
as a
way to protect Earth from impacts with celestial bodies.
Personally I
can see no reason for restricting the idea of Earth defense to
dueling
with asteroids and comets. As I suggested years ago
http://abob.libs.uga.edu/bobk/nucreaim.html
,
http://abob.libs.uga.edu/bobk/rma.html
&
http://abob.libs.uga.edu/bobk/petition.html
there are many benefits that would come from accelerated Space
development focused on protecting our environment. The most
immediate
boon being a rapid increase in the ability to gather real-time
knowledge of how Life support systems on Earth are being affected
by
our own activities as well as by variations in the immediate
solar
environment. A well endowed, internationally coordinated, effort
could
provide much greater information return than the various
marginally
funded projects can at present. This would basically be an
expansion
and institutionalization of the International Geosphere-Biosphere
Program:
http://www.igbp.kva.se/
http://www.nas.edu/ssb/cesexsum.html
In essence, I fancy Earth protection as an evolution of the
function
that national defense has held--attempting to minimize danger to
citizenry while maintaining a status quo. Obviously this is
a social,
philosophical, and funding issue; the question is whether
resources
will continue to flow most readily to short-term money-making
projects
or to endeavors that can enhance real wealth, which is accurate
knowledge of how our world works. Perhaps increasing evidence of
rapid
climate change may help to tip various tills toward survival
enhancement.
An interesting example of unusual climate change occurred around
1740
AD. This, according to Mike Baillie (Exodus to Arthur, page 143),
produced a tree-ring event that coincides with the largest
temperature
reduction in Manley's Central England temperature record, which
runs
from 1659 to the present. Years ago I culled some 'meteor'
observations
from Philosophical Transactions and, upon running across them
again and
realizing they were from right around this time period (December
1737),
I put them on my web-site in the DjVu format:
http://abob.libs.uga.edu/bobk/phil/
As an inducement to obtain and install the DjVu plug-in, I'll
provide a
few interesting lines:
"6) This meteor was seen at Venice at the same time; and,
over Kilkenny
in Ireland, it appeared like a great Ball of Fire; which burst
with an
Explosion that shook [a] great Part of the Island, and set the
whole
Hemisphere on Fire; which burnt most furiously, till all the
sulphureous Matter was spent."
Point five is also intriguing:
"5) The whole Time was attended with an extraordinary Heat
of the Air
for the Season [early December]; for I was obliged to strip to
the
Shirt, though abroad in the Air all the time."
What was going on here? I'm curious to hear the views of other
readers.
To me such observations underscore how little we actually know of
what
can happen within this dynamic environment we depend upon.
Links pertinent to 1737:
http://www.as.wvu.edu/~jel/skywatch/swfttle.html
http://comets.amsmeteors.org/comets/pcomets/109p.html
http://amsat.org/amsat/ftp/articles/satgen/sgen196.txt
http://cfa-www.harvard.edu/iau/Comm6/CBATReport1992.html
http://www.rog.nmm.ac.uk/leaflets/solar_system/section3.16.html
http://www.acsu.buffalo.edu/~avk/tXt/projects.html#Proposal
http://www.ngdc.noaa.gov/seg/hazard/tsevsrch.shtml
[i.e. begin 1736 end 1740]
http://www.usgs.gov/public/press/public_affairs/press_releases/pr540m.html
http://cires.colorado.edu/~bilham/India.html
http://www.geo.mtu.edu/weather/aurora/
http://www.it.cc.mn.us/literature/rich6.html
http://www.wufoc.com/ufofiles/english/issue_3/ussr2.htm
[Caution! Alien noise. ;^)]
[ http://www.tuvpo.com/deprem1e.html
]
There are heaps of interesting reports that we need to better
understand:
http://abob.libs.uga.edu/bobk/hotwater.html
http://abob.libs.uga.edu/bobk/discd.html
http://abob.libs.uga.edu/bobk/korea/
http://abob.libs.uga.edu/bobk/dcj/
It's a shame that so few resources are directed toward uncovering
past
observations--the present often does not explain what occurred
earlier.
But hey, if we fail to maintain the biosphere to our advantage
and
run-away change starts to stress us out, there is a fall-back. We
can
just wait for good-old Hsp90 to kick in and make us over again:
http://www.hhmi.org/news/lindquist.htm
http://cnn.com/TECH/science/9811/25/sudden.evolution.ap/
--Wonder if we can get even more pig-headed?/!
Signaling noisily.
bobk
Bob Kobres
bkobres@uga.edu
http://abob.libs.uga.edu/bobk
706-542-0583
Main Library
University of Georgia
Athens, GA 30602
=============
(5) ASTEROID IMPACT HAZARDS ON A POPULATED EARTH
New book by John S. Lewis (1999): Comet and Asteroid Impact
Hazards on
a Populated Earth, Academic Press Inc; ISBN: 0124467601
This work explores the anticipated consequences of comet and
asteroid
impact. It presents the first computer simulations of the hazards
of
comet and asteroid bombardment of a populated Earth. Previous
estimates
of fatality and damage rates on the 100 to 10,000 year time scale
are
shown to be too low because they neglect rare, highly lethal
outriders
of the populations of bombarding objets, those with exceptional
strength, unusually low entry velocity, and near-horizontal entry
angles. This is an assessment of both the mean casualty rate and
the
expected statistical fluctuations in that rate. A break down of
fatality and damage rates by impactor energy and compositional
class
suggests lessons for both asteroid search strategies and
interdiction
techniques. Key features of this title include: quantitative
treatment
of impact hazards, including structural blast damage, firestorm
ignition and tsunami generation; a detailed and realistic Monte
Carlo
simulation program; a realistic treatment of the impactor
population,
composition, and orbits; attention to economic and public policy
issues
of warning, interdiction and asteroid and comet search
strategies;
quantitatively rigorous treatment of the state of impact hazards
with
comparisons to historical records; and eight pages of colour
plates
depicting impacts and hazards related to meteorites.
For orders see
http://www.amazon.co.uk/exec/obidos/ASIN/0124467601/qid=941641435/sr=1-1/026-9150131-4374668
=============
(6) ORBFIT 2.0
From Andrea Milani <milani@lagrange.dm.unipi.it>
Dear OrbFitters and dear friends,
This message announces the new and significantly improved
distribution
2.0 of the free software OrbFit.
The purpose of the software system we are distributing,
maintaining and
continously upgrading, is to make available to observers of
asteroids
an easy to use but accurate and reliable software to compute
preliminary orbits, ephemerides, improved orbits (by differential
corrections), identifications, and other auxiliary functions, to
allow
the processing of astrometric observations and the planning of
observational campaigns (for example to recover lost objects).
Main improvements with respect to 1.9.0 are:
1) Automatic astrometric observation weighting, according to past
performance of each observatory (for each observing technology)
on
numbered asteroids.
2) Radar observations are handled, with input from JPL data
files.
3) Graphical interface to run the programs and an online help
with
TCL/TK interface (see doc/README.tcl).
4) New MOID computation using Lowell Obs. subroutine based on
method of
Sitarski.
5) The MS-Windows version is now more stable, and includes
plotting
capability.
6) Generation of ephemerides (on the sky) from fitobs.
We are presently working toward several improvements, described
in the
file README.workinprog which is enclosed with the distribution;
the
ones most likely to be available with the next release, or even
as
patches, are the following:
1) Weighting of photometric observations based upon past
performances
of each observatory.
2) Star maps superimposed on observation predictions. This
will
require gnuplot 2.7, which is not yet available for some
operating
systems.
3) Light version that can run without JPL ephemerides.
4) Yarkovsky effect. Already available as an undocumented
feature, but
not properly tested.
Please note the ftp server has moved. The software can now be
obtained
at:
ftp://newton.dm.unipi.it/pub/orbfit
A README file to be found therein provides all the necessary
instruction for installation on all flavours of UNIX and WINDOWS
computers.
This software system has been developed by a consortium including
A.
Milani and S. Chesley (Pisa University), M. Carpino (Astronomical
Observatory Milano/Brera), Z. Knezevic (Astronomical Observatory
Belgrade) and G. B. Valsecchi (CNR Rome).
Another new feature is the availability of the free software
Orbit9 as
an add-on to OrbFit. This software, previously distributed
separately,
is used to propagate orbits of asteroids for long time spans
(tens of
millions of years for main belt asteroids). To get this, you
should ftp
the archive orbit9.tgz from
ftp://newton.dm.unipi.it/pub/propel/orbit9/
and unpack it following the instructions in the file
./doc/README.orbit9.
Copyright (C) 1997-1999 OrbFit Consortium
This program is free software; you can
redistribute it and/or modify
it under the terms of the GNU General Public
License as published by
the Free Software Foundation; either version 2
of the License, or
(at your option) any later version.
To contact us:
milani@dm.unipi.it
chesley@dm.unipi.it
carpino@brera.mi.astro.it,
giovanni@saturn.ias.fra.cnr.it,
zoran@aob.bg.ac.yu
=============
(7) EARTH-IMPACTING SUN STORMS PREDICTED
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Particle Physics and Astronomy Research Council
Swindon, England
2 November 1999
EARTH-IMPACTING SUN STORMS PREDICTED
Astrophysicists will be able to predict in detail the effect of
solar-storms on Earth. Using a powerful new computer called
MIRACLE*,
PPARC scientists are researching techniques to provide early
warning
of the potentially devastating impact of solar storms on
satellites
and power supplies.
Solar storms are caused by huge explosions on the surface of the
sun,
which stream out into space, sometimes towards Earth. The heat
from
solar storms has caused low orbiting satellites to drop out of
the
sky. This happens when the Earth's atmosphere expands causing the
satellites to 're-enter' the atmosphere and burn-up. Solar storms
also affect the magnetic composition of the ionosphere. This
disrupts
radio signals, causes electrical power blackouts and surges in
oil
pipelines.
"Space weather prediction is an exciting area of research.
Using this
new computer we are able to develop models that can be used to
warn
telecom network operators, power suppliers and radio operators
about
the effects of solar storms -- they can then take action to
minimise
damage." said PPARC researcher Dr Alan Aylward.
Research satellites like SOHO warn scientists that a solar storm
is
heading towards Earth, the computer models take over from there
to
predict the impact of each storm.. PPARC fund both the UK's
participation in SOHO (an ESA mission) and the theoretical work
to
interpret data from spacecraft.
Prediction of solar storms is only one of the uses for the new
computer. It will make it possible to investigate how stars and
planetary systems form and predict the fate of giant stars
several
times hotter than the Sun. Other planets can also be modelled by
MIRACLE. "It used to take 7 earth-days to model one Jupiter
day,
MIRACLE should allow us to run models in 'real time' " said
Dr Steve
Miller. "It will also let us model the giant planets that
have been
discovered orbiting nearby stars, which leads us into whole new
areas
of research".
The computer, which can perform 15 billion calculations per
second,
was financed by PPARC, the UK's strategic science investment
agency
and has been provided as a research tool for the consortium of
astronomers from University College London, University of
Hertfordshire, Imperial College of Science, Technology and
Medicine,
and Queen's University, Belfast.
Contacts:
Particle Physics and Astronomy Research Council
Press Office:
Charlotte Allen, Press Officer
Tel: 01793 442012 Mobile: 07881 645121
University College London
Press Office:
Patrick Edwards, Press Officer
Tel: 0171 391 1621
Department of Physics and Astronomy:
Dr Steve Miller
Tel: 0171 419 3443/3490 (work)
Notes for Editors
*MIRACLE is an acronym for Multi-Institutional Research
Astrophysics
Computing. The MIRACLE Consortium is a group of research
astronomers at
the leading edge of modelling the astronomical environment from
the Milky
Way to the upper levels of the Earth's atmosphere.
The MIRACLE computer is Silicon Graphics Origin 2000. The
computer has
24 individual processors, each of which can be harnessed to
produce over
15 gigaflops (15 billion calculations per second) of computing
power and
access 6 gigabytes of memory.
MIRACLE is one of two new computers in UCL's HiperSpace Centre
officially
opened by Lord Sainsbury on Friday November 5th 1999.
PPARC, the UK's strategic science investment agency, funds the
MIRACLE
computer through a research grant to University College London.
The grant
includes provision of the SG Origin 2000 machine and support
staff to
operate it. The value of the grant is approximately £250,000.00.
PPARC delivers world leading science, technologies and people.
Technologies developed by PPARC research can be found in
business, defence,
industry and education. There are direct benefits to society in
terms of
development of new materials and products, raising the skills
base, and
maintaining the UK as a world leader in this field.
Minister for Science Lord Sainsbury will join Professor Chris
Llewellyn
Smith, UCL Provost and John Fleming of SGI, for the launch of the
new
HiperSPACE Centre on Friday 5 November 1999 at 2.00pm in the
Eisai Lounge,
University College London, Gower Street. Members of the press
wishing to
attend should contact UCL Media Relations on 0171 391 1621.
===============
(8) ASTRONOMERS FIND EVIDENCE OF FIRST PLANET ORBITING A PAIR OF
STARS
From NASANews@hq.nasa.gov
Donald Savage
NASA Headquarters, Washington,
DC
November 3, 1999
(Phone: 202/358-1547)
Amber Jones
National Science Foundation, Arlington, VA
(Phone: 703/306-1070)
RELEASE: 99-127
ASTRONOMERS FIND EVIDENCE OF FIRST PLANET ORBITING A PAIR OF
STARS
Astronomers have found evidence of the first known planet
orbiting a
pair of stars. Previously, planets have been found circling
only
single stars.
The Microlensing Planet Search (MPS) project, led by David
Bennett and
Sun Hong Rhie of the University of Notre Dame, South Bend, IN,
used a
technique called gravitational microlensing that may have
revealed a
planet about three times the mass of Jupiter orbiting a binary
star
system. The researchers, who are supported by NASA's
Astronomical
Search for Origins Program, the National Science Foundation (NSF)
and
the Research Corporation, report their results in the November 4
issue
of Nature.
"Between half and two-thirds of the stars in our solar
neighborhood are
known to be members of binary or multiple star systems,"
said Morris
Aizenman of NSF's Astronomical Sciences Division. "To
find evidence of
a planet orbiting a pair of stars means there could be more
planetary
systems than we previously thought." Astronomers have
detected only
about 20 planets outside our solar system, all orbiting single
stars,
although some of those stars are in binary systems.
Gravitational lensing is based on a property first noted by
Albert
Einstein in the 1930s. When an object such as a star or
planet moves
in front of a more distant star, the gravity of this star or
planet
serves as a "lens," magnifying the light from the
distant star and
making it appear brighter. The Microlensing Planet Search
astronomers
analyzed data from such an event that occurred in 1997, referred
to as
MACHO-97-BLG-41 -- the 41st microlensing event discovered by the
Massive Compact Halo Objects (MACHO) collaboration that
year. During
this 100-day event, the pattern of brightness appeared too
complex to
be produced by a single-star lens.
While Bennett and his colleagues believe the best model for
explaining
this microlensing event is a planet orbiting a binary star
system,
other astronomers have proposed alternative models they believe
could
also fit the data. One possibility is that the orbital
motion of the
binary star system itself could have caused the change in the
observed
brightness of the distant star. Another possibility is that the
distant
star may itself be part of a binary system. These scenarios
will be
tested in future observations.
The MACHO project, which is supported by NSF as part of the
National
Science and Technology Center for Particle Astrophysics at the
University of California at Berkeley, routinely makes data on
microlensing events available to other astronomers. MACHO is
using microlensing to explore tens of millions of stars in a
search for
the "dark matter" that dominates the mass of our
galaxy. Dark matter is
believed to exist because the combined gravity of the known
matter in
the universe is not enough to account for the observed
gravitational
effects.
The MPS astronomers are using the microlensing technique to
search for
planets orbiting stars other than our Sun. For this analysis,
they used
observations from telescopes at the Mount Stromlo Observatory in
Australia and the Wise Observatory in Israel as well as data from
the
NSF's Cerro-Tololo Inter-American Observatory in Chile.
Astronomers at
the Wise Observatory co-authored the Nature report.
More information on MPS can be found on the Internet at:
http://bustard.phys.nd.edu/MPS/
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