PLEASE NOTE:
*
CAMBRIDGE-CONFERENCE DIGEST, 22 April 1998
------------------------------------------
(1) JAPAN WILL SOON BE ABLE TO CONTRIBUTE TO INTERNATIONAL
SPACEGUARD
ACTIVITIES
Syuzo Isobe <isobesz@cc.nao.ac.jp>
(2) JAPAN TO WATCH FOR FALLING STARS & SPACE DEBRIS
Phil Burns <pib@nwu.edu>
(3) JAPAN TO WATCH FOR FALLING SPACE TRASH: RADAR TO SEARCH THE
SKIES,
TELESCOPE TO WATCH FOR ASTEROIDS
MSNBC News <http://www.msnbc.com/news/159978.asp>
(4) THE LATEST LOAD FROM THE WASHINGTON POST
Ed Grondine <epgrondine@hotmail.com>
(5) MISSION TO ASTEROIDS, MARS AND A COMET DELAYED
The Planetary Society <http://www.planet.org.html>
(6) ASTRONOMERS FIND PLANET CONSTRUCTION ZONE AROUND NEARBY STAR
NASANews@hq.nasa.gov
==============================
CONGRATULATIONS, SYUZO ISOBE! JAPAN RISES TO NEO-CHALLENGE
Japan is the first nation to take appropriate action in the
immediate
aftermath of the events surrounding the 'discovery' of asteroid
1997
XF11. Whilst the British Government, in the midst of an ongoing
economic recovery, is cutting funds for solar system astronomy,
closing
down entire observatories (such as the world's most famous RGO)
and
threatening further cuts for other observatories (never mind its
complete ignorance regarding the endeavours by Spaceguard UK to
enhance
British NEO-research), Japan, in the midst of a deepening
economic
recession, has taken brave and far-sighted steps to contribute to
the
international efforts to counter and reduce the threat posed by
comets
and asteroids. This success is largely due to the untiring work
of the
Japan Spaceguard Association (JSGA), headed by Syuzo Isobe. Well
done,
Syuzo!
Benny J Peiser
======================================
(1) JAPAN WILL SOON BE ABLE TO CONTRIBUTE TO INTERNATIONAL
SPACEGUARD
ACTIVITIES
From Syuzo Isobe <isobesz@cc.nao.ac.jp>
Syuzo Isobe
National Astronomical Observatory
2-21-1, Osawa, Mitaka, Tokyo 181, Japan
Tel: 81-422-34-3645, Fax: 81-422-34-3641
E-mail: isobesz@cc.nao.ac.jp
Dear Dr. Peiser:
Members of the CCNet may be interested in the following
information.
The Japanese new 1 m telescope project will start this fiscal
year.
The Japanese government publicized on April 20 that a new
NEO-Debris 1
m telescope is budgeted for this year and the next two years. The
Japan
Spaceguard Association (JSGA) has been lobbying to build a 1 m
NEO
telescope to different agencies of our Government with a paper
supported by the Spaceguard Foundation, and now we are getting
gradual
support. The Science and Technology Agency (STA) showed their
intention
to support our proposal last year. After many discussions within
the
JSGA, the NASDA (National Space Deveopment Agency), the NAL
(National
Aeronautic Laboratory), the STA has now decided to fund 2 billion
yen
(around 15 million dollars) for a space debris radar and a 1m
optical
telescope for the detection of NEOs and space debris.
The building of the 1 m telescope will start this fall. Tentative
specification of this telescope is 3 degree field with 12 to 14
2k x 4k
mosaic CCD. All the paprameters should be optimized at its site,
Bisei
Town, which has light pollution ordinance. After the completion
of this
telescope in three year, Japan will be able to contribute to the
international Spaceguard activities. I will forward futher
details
as soon as they become known.
Syuzo Isobe
===========================
(2) WATCH FOR FALLING STARS & SPACE DEBRIS
From Phil Burns <pib@nwu.edu>
The article at
http://www.msnbc.com/news/159978.asp
reports that "Japan will build a radar and telescope system
to monitor
asteroids or any space debris that could threaten rockets and
satellites launched from Earth." $9.2 million has been
allocated to the
five year project.
-- Phil "Pib" Burns
Northwestern University, Evanston, IL. USA
pib@nwu.edu
http://pibweb.it.nwu.edu/~pib/
======================
(3) JAPAN TO WATCH FOR FALLING SPACE TRASH: RADAR TO SEARCH THE
SKIES,
TELESCOPE TO WATCH FOR ASTEROIDS
From MSNBC News <http://www.msnbc.com/news/159978.asp>
MSNBC Staff and wire reports
TOKYO, April 21 — Japan will build a radar and telescope
system to
monitor asteroids or any space debris that could threaten rockets
and
satellites launched from Earth. The new radar will be capable of
searching to an altitude of 620 miles for debris such as spent
boosters
and inactive satellites, a spokesman for Japan’s Science and
Technology
Agency said Tuesday.
THE AGENCY has budgeted $9.2 million for the five-year project.
The
radar facility is to be built on the site of a uranium processing
plant
in rural Okayama prefecture, 340 miles west of Tokyo, said the
spokesman, who spoke on condition of anonymity. The agency also
plans
to build a high-powered telescope to search for asteroids on a
collision course with Earth, the spokesman said.
More than 8,000 bits of space debris are now orbiting Earth,
according
to the North American Air Defense Command, which monitors the
debris
for the United States and Canada.
Governments track the debris closely to predict when and where it
might
enter the atmosphere and to prevent returning space junk from
triggering a false alarm in missile-attack warning systems.
In the United States, several reports have raised concerns about
the
potential for damage to spacecraft from collisions with orbital
debris.
And in March, astronomers raised an alarm over an asteroid that
is
projected to make an unusually close approach to Earth in the
year
2028. The latest calculations indicate that the asteroid will not
actually hit the earth.
(C) 1998 AP, MSNBC
========================
(4) THE LATEST LOAD FROM THE WASHINGTON POST
From Ed Grondine <epgrondine@hotmail.com>
The Washington Post, one of the two dailies here in Washington,
and
hence one the two sources which provide information to the
legislators
here, launched a pre-emptive strike against the effect which the
two
summer movies, "Deep Impact" and "Armageddon"
are sure to have. In a
long article in their Sunday "Washington Post Magazine"
they ran an
article by Joel Achenbach on "The Next Big Thing: Asteroid
Impacts,
Dinosaur Extinctions and the Mysteries of Catastrophe."
In order to give their correspondent some credibility, they
sent him
dowm with the Planetary Society's expedition to Belize, and he of
course had to fess up that indeed an asteroid may have killed the
dinosaurs. He then went on to some amazingly misleading
statements,
statements which support the Post's view of the hazard presented
by
impactors:
"It is extremely likely that you will not be killed by an
asteroid or
comet and that no one you know will be killed and that no other
current
inhabitants of the Earth will be killed."
Hmmm, let's see. The chances of a small comet or asteroid of the
Tunguska class falling are anywhere from 1 per 35 years (Gorelli)
to 1
per 50 to 100 years (Steel) to somewhat higher (say 1 per 200
years
from Morrison?) The chances of this detonating over water
are about 7
out of 10, and over an uninhabited area about 1.5 out of
10. Using the
middle estimate (Steel) we end up with about a 15% chance that a
nation
state will be destroyed during a child's lifetime.
This statement is not accidental. Achenbach ignores Clube and
Napier's
work, and instead concentrates on a new theory by Al Fischer that
when
our Solar System passes through the arms of the Milky Way about
once
every 150 million years it dislodges comets. The reason Achenbach
used
this model is that the next passing will not occur for another 8
million years, so of course we do not need to do anything about
it now.
Of course, by Clube and Napier's model we passed through the
plane of
the Milky Way about 2 million years ago and we are in deep
kim-chee
right now, so of course Auchenbach is going to ignore it.
If I wrote a letter to the Post right now I would just be
ignored, but
there are people on this list whose letters it would be
impossible to
ignore. The editors of the Post have conveniently provided
an e-mail
form for contacting them, and it can be found at
http://www.washingtonpost.com/wp-srv/edit/letters/letterform.htm
It's time to call them down on this nonsense.
Ed Grondine
============================
(5) MISSION TO ASTEROIDS, MARS AND A COMET DELAYED
From The Planetary Society <http://www.planet.org.html>
Software Troubles and Late Electronics System Force NASA To
Postpone
Deep Space 1
The planned July 1998 launch of NASA's Deep Space 1
technology
validation mission from Cape Canaveral, Florida, has been
rescheduled
for October.
The delay is due to a combination of late delivery of the
spacecraft's
power electronics system and an ambitious flight software
development
schedule, which together leave insufficient time to test the
spacecraft
thoroughly for a July launch.
The power electronics system regulates and distributes power
produced
by not only the solar concentrator array, a pair of experimental
solar
panels composed of 720 cylindrical Fresnel lenses, but also by an
on-board battery. Among many other functions, it helps the solar
array
to operate at peak efficiency, and ensures that the battery is
able to
cover temporary surges in power needed so that the ion propulsion
system (which needs electricity for its basic operations)
receives a
steady power supply.
"With a new launch date for this bold mission, we can be
more confident
that we will be ready to fully exercise our payload of important
technologies," explained Chief Mission Engineer Marc Rayman
of NASA's
Jet Propulsion Laboratory in Pasadena, California. "The
entire DS1 team
looks forward to this opportunity to make a significant
contribution to
science missions of the future through the capabilities we are
testing
on DS1."
Deep Space 1 is the first launch in NASA's New Millennium
program, a
series of missions designed to test new technologies so that they
can
be confidently used on science missions of the 21st century.
Among the
12 technologies the mission is designed to validate are ion
propulsion,
autonomous optical navigation, a solar power concentrator array
and an
integrated camera and imaging spectrometer.
The earlier July launch period for DS1 allowed it to fly a
trajectory
encompassing flybys of an asteroid, Mars, and a comet. By the end
of
May, the mission design team is scheduled to finalize new target
bodies
in the solar system for DS1 to encounter based on an October
launch
date.
---------------
MORE NEWS ON DEEP SPACE 1
Editor's note: Deep Space 1 will no longer visit asteroid 3352
McAuliffe, Mars, and comet West-Kohoutek-lkemura. The launch
delay was
announced after this article went to press. Mission planners will
announce the new targets for this mission by the end of May. The
full
text and graphics for this article will appear in the May/June
1998
issue of The Planetary Report. This publication goes out to all
members
of the Planetary Society. If you're not already a member, we
encourage
you to join.
Deep Space 1: Exploration Technology for the 21st Century
by Robert M. Nelson and Marc D. Rayman
This summer NASA takes a revolutionary step when it launches Deep
Space
1 (DS1). During its flight, the spacecraft will visit asteroid
3352
McAuliffe, the planet Mars, and comet West-Kohoutek-lkemura. But
its
primary goal is not to study these fascinating bodies; rather, as
a
member of the New Millennium program, its job is to pave the way
for
future, even more exciting, space science missions.
NASA has already flown missions to asteroids, comets, and Mars,
so what
makes DS1 unusual? It will demonstrate a dozen technical
innovations
that will serve as foundation technologies for the next
generation of
deep-space missions. Foremost among these new technologies will
be
solar electric propulsion (SEP), which will enable a whole class
of
ambitious missions that are simply impractical or unaffordable,
with
the standard chemical propulsion available today.
A Test Drive
DS1 will be launched from Cape Canaveral on the first Delta 7326
rocket, a low-cost member of the Delta 11 family. DS1 is so small
that
even this economy-class launch vehicle will be able to carry a
second
spacecraft -- SEDSAT-1, an Earth orbiter built at the same time
by
students at the University of Alabama in Huntsville.
Once in space, DS1 will be checked out and certified by the
mission
operations team, and then the SEP system will begin thrusting.
Instead
of burning a strong, short pulse of chemical propellant, followed
by a
long interplanetary cruise, the SEP system will sustain a tenuous
but
very high-velocity stream of ionized xenon. This stream will
create a
gentle, steady thrust that will propel the spacecraft almost
continuously during interplanetary cruise.
Although the thrust of SEP is small, its advantage accrues
because the
exhaust velocity of the ion rocket is many times greater than the
exhaust velocity of a conventional chemical system. The bottom
line is
that SEP requires far less propellant than a chemical rocket to
deliver
the same payload mass to a target, It takes time for the gentle
thrust
to build up high spacecraft velocity, so SEP is appropriate only
for
missions requiring high energy or long trips.
Within a month of launch, DS1 will have accomplished most of its
major
objectives, and we will have assessed its payload of advanced
technologies. If a technology fails during the flight, even if it
causes the loss of the spacecraft, we may still regard the
mission as a
success if it achieves the program goal of reducing the risk for
future
science missions. It is in these future missions that the real
science
return of DS1 will be found. But this high-risk project will
attempt to
return science during its test flight....
The flight of DS1 will test new autonomy technologies,
solar
concentrator arrays, and a variety of telecommunications and
microelectronics devices. Autonomy, which in this case means the
ability of the spacecraft to make its own decisions, can help
reduce
the heavy burden on NASA's Deep Space Network (DSN). As more and
more probes are sent into space in the coming years, it will be
harder
for the DSN to communicate with all of them as frequently as it
has
done in the past. With autonomy technologies allowing spacecraft
to
operate for longer times without detailed instructions from
Earth, the
precious resources of the DSN can go further. In addition, by
placing
more responsibility on the spacecraft, we reduce delays caused by
signal travel times and limited communications rates. Despite the
potential advantages, it is easy to see that onboard
decision-making
systems entail risk for the first user. If the autonomy systems
on DS1
perform as planned, future mission teams can be more confident
about
leaving important decisions to the spacecraft.
One of the powerful autonomy technologies on DS1 is the
navigation
system. It uses images of main-belt asteroids viewed against the
background stars to compute the spacecraft's position. As the
spacecraft travels, foreground objects (the asteroids) will
appear to
move relative to the background stars. The apparent shift, or
parallax,
gives the navigation system information from which to triangulate
the
spacecraft position. The navigation system then uses positions
calculated at earlier times to determine trajectory, making
allowances
for SEP thrusting, gravitational pulls of the Sun and planets,
and
other forces. If the navigation system finds that it is off
course, it
can make a course correction by adjusting the direction or
duration of
SEP thrusting....
(C) 1998 The Planetary Society
====================
(6) ASTRONOMERS FIND PLANET CONSTRUCTION ZONE AROUND NEARBY STAR
From NASANews@hq.nasa.gov
Donald Savage
Headquarters, Washington,
DC
April 21, 1998
(Phone: 202/358-1547)
Jane Platt
Jet Propulsion Laboratory, Pasadena, CA
(Phone: 818/354-5011)
Andrew Perala
W. M. Keck Observatory, Mauna Kea, Hawaii
(Phone: 808/885-7887)
RELEASE: 98-65
ASTRONOMERS FIND PLANET CONSTRUCTION ZONE AROUND NEARBY STAR
NASA astronomers using the new Keck II telescope in Hawaii have
discovered what appears to be the clearest evidence yet of a
budding
solar system around a nearby star.
Scientists released an image of the probable site of planet
formation
around a star known as HR 4796, about 220 light-years from Earth
in the
constellation Centaurus. The image, taken with a sensitive
infrared
camera developed at NASA's Jet Propulsion Laboratory (JPL),
Pasadena,
CA, shows a swirling disk of dust around the star. Within
the disk is
a telltale empty region that may have been swept clean when
material
was pulled into newly formed planetary bodies, the scientists
said.
"This may be what our solar system looked like at the end of
its main
planetary formation phase," said Dr. Michael Werner of JPL,
who
co-discovered the region, along with Drs. David Koerner and
Michael
Ressler, also of JPL, and Dana Backman of Franklin and Marshall
College, Lancaster, PA. "Comets may be forming right
now in the disk's
outer portion from remaining debris."
The discovery was made on March 16 from the giant 33-foot
(10-meter)
Keck II telescope atop Mauna Kea, Hawaii. Keck II and its
twin, Keck
I, are the world's largest optical and infrared telescopes.
Attached
to the Keck II for this observation was the mid-infrared camera,
developed by Ressler at JPL and designed to measure heat
radiation.
The four scientists reported their discovery in a submission to
The
Astrophysical Journal Letters. The disk was discovered
independently
and contemporaneously at the Cerro Tololo Observatory in Chile by
another team of scientists, led by Ray Jayawardhana of the
Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, MA,
and
Dr. Charles Telesco of the University of Florida, Gainesville.
Koerner of JPL said the finding represents a "missing
link" in the
study of how planetary systems are born and evolve.
"In a sense, we've
already peeked into the stellar family album and seen baby
pictures and
middle-aged photos," Koerner said. "With HR 4796,
we're seeing a
picture of a young adult star starting its own family of
planets. This
is the link between disks around very young stars and disks
around
mature stars, many with planets already orbiting them."
"This is the first infrared image where an entire inner
planetary disk
is clearly visible," Werner said. "The
planet-forming disk around the
star Beta Pictoris was discovered in 1983 by the Infrared
Astronomical
Satellite (IRAS), and also later imaged with the Hubble Space
Telescope, but glaring light from the star partially obscured its
disk."
The apparent diameter of the dust disk around HR 4796 is about
200
astronomical units (one astronomical unit is the distance from
Earth to
the Sun). The diameter of the cleared inner region is about
100
astronomical units, slightly larger than our own solar
system.
HR 4796 was originally identified as an interesting object for
further
study by Dr. Michael Jura, an astronomy professor at the
University of
California, Los Angeles. The star, HR 4796, is about 10
million years
old and is difficult to see in the continental United States, but
is
visible to telescopes in Hawaii and the southern hemisphere.
The discovery of the HR 4796 disk was made in just one hour of
observing time at Keck, but the JPL team plans to return to
Hawaii in
June for further studies. They hope to learn more about the
structure,
composition and size of this disk, and to determine how disks
around
stars in our galaxy produce planets. They plan to study
several other
stars as well, including Vega, which was featured prominently in
the
movie, "Contact."
The Harvard/Florida research team that also found the HR 4796
disk
included Drs. Lee Hartmann and Giovanni Fazio of
Harvard-Smithsonian
Center for Astrophysics, and Scott Fisher and Dr. Robert Pina of
the
University of Florida.
JPL's use of the Keck telescope is supported by NASA's Origins
program,
a series of missions to study the formation of galaxies, stars,
planets
and life, and to search for Earth-like planets around other stars
that
might have the right conditions for life.
The W. M. Keck Observatory is owned and operated by the
California
Association for Research in Astronomy, a joint venture between
the
University of California, California Institute of Technology
(Caltech),
Pasadena, CA, and NASA. Use of the Keck Observatory for
Origins
research is managed by JPL for NASA's Office of Space Science,
Washington, DC. JPL is a division of Caltech.
The research of both teams was supported in large part by the
NASA
Origins Program, with additional support to the CfA-Florida team
from
the National Science Foundation, the National Optical Astronomy
Observatories, and the Smithsonian Institution; and with
additional
NASA support for the CalTech/JPL-Franklin & Marshall team,
including
use of the Keck Observatory.
- end -
NOTE TO EDITORS: The Keck II image of HR 4796 and
information on the
MIRLIN camera are available on the World Wide Web at:
http://cougar.jpl.nasa.gov/mirlin.html.
A false-color image of the HR 4796A disk is available at:
http://www.astro.ufl.edu/news/
Information on the Keck Observatory is available at:
http://www2.keck.hawaii.edu:3636
Images at:
Information on the Origins program is available at:
http://origins.jpl.nasa.gov
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