PLEASE NOTE:
*
Date sent: Fri, 16 Jan
1998 09:24:23 -0500 (EST)
From:
Benny J Peiser B.J.PEISER@livjm.ac.uk
Subject:
CC-DIGEST, 16 January 1998
To:
cambridge-conference@livjm.ac.uk
Priority: NORMAL
CAMBRIDGE-CONFERENCE DIGEST, 16 January 1998
-------------------------------------
(1) ICE AGE METEORITE FINDS IN ARIZONA
(2) TRYING TO TRACK THE REAL NATURE OF ASTEROIDS:
PLANNING BEGINS ON ASTEROID NANO-ROVER
(3) TRYING TO TRACK THE REAL NATURE OF COMETS:
STARDUST MISSION TO START SPACECRAFT ASSEMBLY
& TEST
(4) ANNOUNCEMENT OF OPPORTUNITY FOR 10 STARDUST EDUCATOR FELLOWSHIPS
=======================================================================
(1)
ICE AGE METEORITE FINDS IN ARIZONA
From: Phil Burns pib@nwu.edu
News Services
University of Arizona
--------------------------------------------------------------------
From: Lori Stiles, UA News Services, 520-621-1877,
lstiles@u.arizona.edu
Contact(s):David A. Kring, 520-621-2024,
kring@lpl.arizona.edu;
James D. Kriegh, 520-297-4161; John Blennert, 520-325-8585;
Ingrid
Monrad, 520-297-9454
--------------------------------------------------------------------
January 15, 1998
Gold Basin Meteorite -- Arizona's newest official meteorite is
a unique
'fossil' strewn across large area
(NOTE -- Kriegh and Monrad have donated five fragments of the
Gold
Basin meteorite to the UA Mineral Museum, Flandrau Science
Center,
where they are on display.)
No eyewitness recorded the fall of Arizona's newest official
meteorite. The
unique "Gold Basin" meteorite exploded over more than
50 square miles of
Mohave County in northwest Arizona at the end of the last Ice
Age.
A small field team from Tucson, including a retired civil
engineering
professor who discovered the meteorite, began collecting pieces
of the find
two years ago. But it will take years to gather the remaining
stones and
assemble the details of what happened, according to The
University of
Arizona scientist who is part of the team working to recover the
entire
meteorite.
"As far as I know, this is the first 'fossil' strewn
field found
outside of Antarctica," said David A. Kring, geologist and
senior
research associate with the Lunar and Planetary Laboratory at The
University of Arizona in Tucson. That the meteorite fragments
survived
exposure to the elements for 20 millennia says that conditions
even during
the last of the Ice Age must have been fairly mild, he added.
Kring, who directs the Lunar Lab's Meteorite Recovery Program,
did a
series of analyzes to classify the meteorite. Classification is
requisite for a meteorite to be officially recognized by the
Meteorite
Nomenclature Committee, the international body of scientists who
assess
meteorite finds. The Gold Basin meteorite this week brings the
number of
officially approved Arizona meteorites to 31.
Radiocarbon tests at the University date the Gold Basin
meteorite at
20,000 years. Kring theorizes that 20,000 years ago, a small
asteroid
hit Earth's upper atmosphere with an energy of between ten to
1,000
tons of TNT. Preliminary evidence suggests the asteroid may have
been a
meter, perhaps two meters, in diameter. It lost energy as it
plowed through
Earth's ocean of air, then it exploded, probably 10 to 30
kilometers above
the ground.
All other known strewn fields of this type of asteroid, called
a type
L4 ordinary chondrite, are "witnessed falls," or those
seen to explode and
fall to Earth, Kring said. L4 ordinary chondrites are relics of
the original
debris that orbited the sun when it coalesced. The debris
accreted to form a
small planetary body about 4.56 billion years ago, probably in an
orbit
between the planets Mars and Jupiter, the region now known as the
asteroid
belt.
"Gold Basin is also special because it is one of the most
numerous
collections of fragments ever found," Kring said.
"We've found more
than 2,000 fragments so far, and it wouldn't surprise me if we
found
another 10,000 fragments, in addition."
James D. Kriegh of Oro Valley discovered the first two
fragments of the Gold
Basin meteorite on Nov. 24, 1995. Kriegh is a retired UA civil
engineering
professor and member of the Desert Gold Diggers, a group whose
members spend
their spare time gold prospecting. A few years ago, Kriegh heard
a talk by
Kring on how to identify meteorites. Kriegh soon began successful
searches
for meteorites, including the Greaterville meteorite he found in
November
1994.
Kriegh said he and the others garnered between one and 140
pieces of
the meteorite on later field trips. Collecting meteorites that
fell to Earth
20,000 years ago after sitting in space for more than 4 billion
years "is
every bit as exciting as searching for gold," he added.
Kring, Kriegh, and John Blennert and Ingrid Monrad, also of
the Oro
Valley-Tucson area, collaborate in collecting and mapping the
Gold
Basin meteorite fragments, which range in size from a peanut to a
3-pound softball that Blennert recovered. So far, the collection
weighs more
than 34 pounds. The strewn field covers private and federal land,
so the
Gold Basin meteorite recovery team has been coordinating the
project with
the relevant federal authorities.
"It's really a joy to have a person like Kriegh involved
in this,"
Kring said. "I told him these are the things we need to do
to preserve the
scientific integrity of the site, and he did absolutely
everything I asked
him to do. The team mapped the location of every fragment as it
was found,
and they recorded how deep it was in the soil or if it was found
right at
the surface."
"We have not yet hit the edge of the Gold Basin strewn
field in any
direction," Kring said. "We don't know how big this is
going to be,
eventually. Every time we go a little farther, we find more
meteorites. The
goal has been to find as many of these fragments as possible. We
wanted to
find the limits of this field before making it public. The
problem is, the
field is just too big. We may be collecting samples for another
decade."
The largest collection of stones from a single meteorite is
also in
Arizona, Kring added. The community of Holbrook was pelted with
14,000
fragments of a meteorite that exploded in the early evening sky
of July 19,
1912. One fragment severed the branch of a tree when it fell,
witnesses
reported. Fragments from the meteor, an estimated half-meter in
diameter,
showered to Earth over an ellipse roughly 1.5 square miles -- a
much smaller
area than the fall site of the Gold Basin meteorite, which is
estimated to
be two-to-four times larger than the Holbrook asteroid.
An important distinction between the Holbrook fall and the
Gold Basin
meteorite strewn field is that Holbrook is a classic case in
which
important information on the distribution of the fragments was
lost. A
mineral collector in Philadelphia paid Holbrook residents to
collect the
pieces and ship them to him on the train, Kring said. In the Gold
Basin
case, by contrast, he added, "I can tell you precisely where
this sample was
collected, thanks to the efforts of the great field team."
Mapping exactly how meteorite fragments are strewn across the
impact
site is no trivial academic exercise. Mapping the strewn field to
reconstruct how the meteorite fragmented should help scientists
understand what causes meteorites to break apart or survive
intact as
they blast through the atmosphere, Kring noted. This is of great
interest to scientists trying to understand the hazards of
asteroid
impacts.
Given that the world's growing population is expanding over
more of our
planet's surface, relatively common collisions with small
asteroids like the
Gold Basin meteorite and the Holbrook meteorite become growing
hazards,
Kring added.
Ask the astronomers who search the skies for near-Earth
crossing
asteroids: They will tell you a future significant collision is
not
a matter of if, but of when.
=====================================================================
(2) TRYING TO TRACK THE REAL NATURE OF ASTEROIDS:
PLANNING BEGINS ON ASTEROID NANO-ROVER
From The "JPL Universe"
Special issue: 1997 in review
January 9, 1998
Planning begins on asteroid 'nano-rover'
By MARY BETH MURRILL
A formal project office was established in 1997 to manage the
U.S.
contribution to the Japanese-managed Muses-C mission to collect
and
return to Earth a sample from an asteroid.
This innovative mission will use new flight technology,
including solar
electric propulsion, to send a spacecraft to asteroid 4660 Nereus
and
deliver a JPL-developed rover, which measures about the size of a
shoebox,
to the asteroid's surface. The Japanese Muses-C spacecraft will
also fire
explosive charges into the asteroid, collect the samples that are
ejected
from the impacts, and return the samples to Earth in a capsule
for
laboratory analysis. The mission is scheduled for launch in 2002.
"This represents an opportunity for the U.S. and Japan's
space
engineers and scientists to combine their expertise to achieve
major
science and technology goals in a cost-constrained
environment," said
Ross Jones, project manager for the U.S. portion of the mission
called
Muses-C ("N" stands for "NASA"). Overall
management of the Muses-C project
resides at Japan's Institute of Space and Astronautical Science.
In addition to providing the rover, JPL will arrange for the
testing of the
Muses-C reentry heat shield at NASA's Ames Research Center,
arrange for
supplemental Deep Space Network tracking of the spacecraft, and
assist in
spacecraft navigation. JPL's responsibilities also include
arranging for
recovery of the return capsule and performance of work to meet
the
requirements of the National Environmental Policy Act.
The asteroid samples will be returned to a landing site in the
U..S, and
American and Japanese investigators will collaborate on shared
data from the
rover and the spacecraft. In 1997, the JPL Muses-CN project team
completed
hardware and software integration of a nano-rover prototype.
Performance
evaluations of the camera and spectrometer for the rover also
began, as did
research and analysis of navigation and sample reentry work.
Preliminary
plans for the heat shield design review and testing are in place
at the Ames
Research Center.
Muses-CN project highlights at JPL in the coming year will
include the
completion of the rover engineering model design, and release of
the
announcement of opportunity to the science community, beginning
the
selection process for scientists who will be investigators on the
project.
==========================================================================
(3) TRYING TO TRACK THE REAL NATURE OF COMETS:
STARDUST MISSION TO START SPACECRAFT ASSEMBLY
& TEST
From The "JPL Universe"
Special issue: 1997 in review
January 9, 1998
Stardust mission to start spacecraft assembly, test
By MARY BETH MURRILL
Stardust, the "faster, better, cheaper" Discovery
Program mission that will
send a spacecraft to gather a sample from a comet, has met the
milestones
necessary to begin assembly and test of the spacecraft hardware
and software
in early January at Lockheed Martin Astronautics in Denver.
Scheduled for launch in February 1999, the Stardust spacecraft
will
embark on a seven-year journey through the coma and to within
about 150
kilometers of the nucleus of Comet Wild-2 (pronounced
"VILT-2). It will be
the first space mission to gather dust and other material from a
comet and
bring it back to Earth for scientific analysis.
Stardust's scientific bounty from its five-year voyage will
also
include samples of the interstellar dust that passes through the
solar
system. Return of this interstellar material will provide
scientists with
their first opportunity for laboratory study of the composition
of the
interstellar medium.
"We've experienced good cost and schedule performance in
1997," said
Stardust Project Manager Dr. Kenneth Atkins. "We've learned
lessons
from previous Discovery projects like Mars Pathfinder, and we've
been
working to leverage common efficiencies with the other Mars
projects
being worked by JPL and Lockheed Martin." The project
finalized its
designs in June and has completed and collected almost all the
hardware and
software components in preparation for the system assembly and
test, Atkins
said.
In February, Stardust mission engineers from JPL and Lockheed
Martin
will convene for a parachute drop test for the Stardust sample
return
reentry capsule system on the snowy desert plateau of the Utah
Test and
Training Range near Salt Lake City. The test range is the
scheduled delivery
site for Stardust's sample return in January 2006.
Comet Wild-2 is a 'fresh' comet that was recently (in 1974)
deflected
by Jupiter's gravity from an earlier orbit lying much farther out
in
the solar system. Having spent most of the last 4.6 billion years
in
the coldest, most distant reaches of the solar system, Wild-2
represents a well-preserved example of the fundamental building
blocks out
of which the solar system formed.
Both the comet and interstellar dust samples will be collected
in
aerogel, a lightweight transparent silica gel, the lowest density
solid
material in the world. (Aerogel was most recently used as a
lightweight
insulating material to protect the Mars Pathfinder Sojourner's
electronics
from the harsh, cold climate of Mars.)
In November, the project received tens of thousands of
responses to its
invitation to the public to "send your name to a
comet." JPL's Microdevices
Lab will etch the names on a silicon wafer that will be placed on
the
Stardust reentry capsule. The names, collected in partnership
with The
Planetary Society, will make a round trip to Comet Wild 2,
returning to
Earth in the sample return capsule.
==========================================================================
(4) ANNOUNCEMENT OF OPPORTUNITY FOR 10 STARDUST EDUCATOR
FELLOWSHIPS
From: Ron Baalke BAALKE@kelvin.jpl.nasa.gov
STARDUST
STARDUST is the fourth of several flight missions in NASA's
Discovery
program. The goal of the Discovery program is to design small,
less
expensive spacecraft with specific scientific goals that can be
built
in 36 months or less. Mars Pathfinder and Lunar Prospector are
examples of
Discovery missions chosen in the past. More information on
this exciting
project can be found on the Internet at:
http://stardust.jpl.nasa.gov/top.html
The spacecraft will launch in February 1999 on board an
expendable
launch vehicle and rendezvous with Comet Wild 2 in January 2004,
coming
within 150 kilometers (93 miles) of the comet's nucleus. The
spacecraft will
be the first ever to collect dust spewed from a comet and return
it to Earth
for detailed analysis. The comet samples are made up of ancient
pre-solar
interstellar grains and material that condensed in the solar
nebula, a
diffuse cloud of gas and dust from which the Sun and planets were
formed. A
sample return capsule will reenter Earth's atmosphere and land on
a dry lake
bed in Utah in January, 2006.
STARDUST WORKSHOP/STARDUST PRESENTERS
Jet Propulsion Laboratory's (JPL) STARDUST Outreach
Opportunity Program is
implementing a nation-wide teacher training initiative and
developing
educational modules. This effort is targeted at grades 4-8.
Initially, 10 STARDUST Educator Fellows will be recruited from
around
the country to help field test the STARDUST educational modules
and
Teacher Training Workshop. This initial group will help test and
modify the
workshop presentation. An additional Announcement of Opportunity
will be
distributed in late spring/summer 1998 to solicit candidates from
which an
additional 15 Educator Fellows will be selected and trained in
fall 1998.
Candidates selected for the STARDUST Educator Fellowship will receive:
* an all-expenses-paid intensive training workshop on: the
STARDUST
mission; science and educational aspects necessary to
effectively
present the STARDUST related topics; and comets and other
small Solar
System bodies. This will take place on three
to-be-determined days during
April 26-May 2 in Denver, Colorado at Lockheed Martin
Astronautics.
* a crash course on presentation strategies and a complete
teacher
training presenter package to use for STARDUST workshops
* priority updates and mailings on the latest STARDUST mission
information and materials
* materials to help plan and promote STARDUST workshops
* continued contact with the STARDUST science team to answer
questions
and to facilitate discussion
The STARDUST Educator Fellowship Team will reflect a
geographically and
institutionally diverse mix of presenters from a variety of
environments -
science centers/museums; school districts; universities;
educational
organizations; etc. - to ensure a diverse team and reach.
In return, selected Fellows must commit to conducting a
minimum of two
educator training workshops per year (approved by the STARDUST
Education
Outreach Team) and to sharing evaluation information from those
workshops
with the STARDUST educational partners.
The training will provide Fellows with a unique opportunity to
interact with
STARDUST Project scientists and engineers. The Education Outreach
Team will
serve as a liaison for the Fellows to facilitate the
dissemination of new
information and continued contact with the STARDUST Fellowship
Team.
While a variety of factors will be used in the final
selection, the
profile of ideal STARDUST Educator Fellows includes:
* actively teaching or conducting teacher training in a formal
or
informal science environment (e.g., school district,
science center,
museum, educational organization);
* willing to conduct a minimum of two STARDUST Teacher
Training
Workshops on their own during each year they are involved
with the
program;
* has a written commitment from their host institution
(current
employer or sponsoring organization) to provide release
time for the
Teacher Training and an expressed willingness to support
the candidate in
conducting at least two STARDUST Teacher Training
Workshops per year;
* willing to submit a resume, two letters of reference and a
two-page
proposal outlining their interest in STARDUST and how they
envision
sharing the educational activities for which they will be
trained;
and
* a commitment to provide timely reports and assessment
information
back to the STARDUST Education Outreach Team.
----------------------------------------------------------------------------
SELECTION
STARDUST Educator Fellows will be chosen from extensive
networks of
classroom teachers, curriculum specialists, and museum/science
center
educators. The STARDUST Educator Fellowship Team will be selected
in
order to provide a geographic and institutional mix of presenters
from a
variety of environments: science centers/museums; school
districts;
universities; educational organizations; etc., ensuring a diverse
team of
STARDUST Fellows across the country. An announcement of those
selected will
be made by March 6, 1998.
Please contact Kerri Beisser at 703/683-9740 for applications
to the
fellowship.
Attn.: Kerri Beisser - STARDUST Educator Fellowship Proposals
Challenger Center for Space Science Education
1029 North Royal Street Suite 300
Alexandria, Virginia 22314
703-683-7546 FAX