MARSBUGS:  
The Electronic Exobiology Newsletter
Volume 5, Number 7, 14 March, 1998.

Editors:

David Thomas, Department of Biological Sciences, University of 
Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu or 
Marsbugs@aol.com.

Julian Hiscox, Division of Molecular Biology, IAH Compton 
Laboratory, Berkshire, RG20 7NN, UK.  Julian.Hiscox@bbsrc.ac.uk or 
Marsbug@msn.com

MARSBUGS is published on a weekly to quarterly basis as warranted 
by the number of articles and announcements.  Copyright of this 
compilation exists with the editors, except for specific articles, 
in which instance copyright exists with the author/authors.  E-
mail subscriptions are free, and may be obtained by contacting 
either of the editors.  Article contributions are welcome, and 
should be submitted to either of the two editors.  Contributions 
should include a short biographical statement about the author(s) 
along with the author(s)' correspondence address.  Subscribers are 
advised to make appropriate inquiries before joining societies, 
ordering goods etc.  Back issues and Word97 files suitable for 
printing may be obtained via anonymous FTP at:  
ftp.uidaho.edu/pub/mmbb/marsbugs.  Also, an official web page is 
under construction.  Currently it is part of 
http://members.aol.com/marsbugs/dave.html (right now, the page 
simply points to the FTP site).

The purpose of this newsletter is to provide a channel of 
information for scientists, educators and other persons interested 
in exobiology and related fields.  This newsletter is not intended 
to replace peer-reviewed journals, but to supplement them.  We, 
the editors, envision MARSBUGS as a medium in which people can 
informally present ideas for investigation, questions about 
exobiology, and announcements of upcoming events.

Exobiology is still a relatively young field, and new ideas may 
come out of the most unexpected places.  Subjects may include, but 
are not limited to:  exobiology proper (life on other planets), 
the search for extraterrestrial intelligence (SETI), ecopoeisis/ 
terraformation, Earth from space, planetary biology, primordial 
evolution, space physiology, biological life support systems, and 
human habitation of space and other planets.
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INDEX

1)	EXOTIC-LOOKING MICROBES TURN UP IN ANCIENT ANTARCTIC ICE
by Dave Dooling

2)	MORE EVIDENCE POINTS TO IMPACT AS DINOSAUR KILLER
JPL release

3)	ASTEROID WILL MISS EARTH BY "COMFORTABLE DISTANCE" IN 2028
JPL release

4)	FLIGHT TEAM MAKES FINAL ATTEMPT TO CONTACT PATHFINDER LANDER
JPL note

5)	MARS PATHFINDER UPDATE
JPL release

6)	MARS PATHFINDER MISSION STATUS
JPL release

7)	STARDUST STATUS REPORT
by Ken Atkins

8)	NEW MARS GLOBAL SURVEYOR IMAGES
JPL release

9)	GALILEO EUROPA MISSION STATUS
JPL release

10)	RAINFOREST MAPPING TECHNIQUES HIGHLIGHTED IN JPL EVENING TALK
JPL release
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EXOTIC-LOOKING MICROBES TURN UP IN ANCIENT ANTARCTIC ICE
by Dave Dooling

13 March, 1998

Mickey Mouse, Klingon, porpoise, sphere, and leftover turkey are 
nicknames given to objects found in ancient Antarctic ice from as 
deep as 1,249 meters beneath Vostok Station.  Two scientists 
exploring a microworld locked in ancient ice have found a wide 
range of life forms from fungi, algae, and bacteria to a few 
diatoms--and a few items with strange shapes.

"We've found some really bizarre things--things that we've never 
seen before," said Richard Hoover of NASA's Marshall Space Flight 
Center.  Hoover and Dr. S. S. Abyzov of the Russian Academy of 
Sciences have been examining deep ice core samples from the Vostok 
Station about 1,000 km (620 miles) from the South Pole.

The objects have fanciful names--like Mickey Mouse and Klingon--
based on passing resemblance.  Hoover expects that most will fall 
into known categories of microorganisms as he and Abyzov study the 
images.

"We're exploring a new world," Hoover said.  "Until we get a lot 
more experience, we're going to see brand new things all the 
time."

The ice harboring these finds is as old as 400,000 years, 
depending on the depth.  Russian scientists at the St. Petersburg 
Mining Institute in St. Petersburg, Russia, developed the 
technology for drilling ice cores without contaminating the 
samples.  Since 1974, they have worked at Vostok Station, 
extracting cores from ever greater depths.

In 1996, the Russian Academy of Sciences announced that a large 
lake of liquid water lies beneath the 3 km-deep glacier at Vostok.

Meanwhile, the ice samples from above the lake's surface (which 
has not been breached) are stirring interest in the scientific 
community.  In the 1970s, Abyzov discovered--and in some cases 
revived--microorganisms in ice that conventional wisdom had said 
was sterile.

Now the discovery of ice and slush on Europa and mounting evidence 
of water on Mars and on our own Moon are leading scientists to 
rethink the possibilities of life elsewhere in the universe.

"These are very important questions for future cosmic research on 
places like Europa, comets, the Martian ice caps," Abyzov said of 
the mysteries in the Antarctic ice.

Hoover and Abyzov are using Marshall's Environmental Scanning 
Electron Microscope (ESEM) to examine material found in the ice.  
Their work is a collaborative effort between NASA/Marshall and the 
Institute of Microbiology of the Russian Academy of Sciences 
working in collaboration with the St.  Petersburg Mining Institute 
and the Institute of Arctic and Antarctic Research in St.  
Petersburg, Russia.

"This is very useful," Abyzov said, "because we do not have this 
equipment in our laboratory.  We have scanning electron 
microscopes, but without the additional equipment you have."

As might be expected, they have found a lot of atmospheric dust 
and debris, and possibly some cosmic dust.

"There are some dust particles with unusual spectra," Hoover said.  
"Which may be cosmic dust particles." The ESEM allows the operator 
to designate a point on a specimen and then scan with X-rays to 
determine what elements are present.  The ratios found in some of 
the dust particles do not match ratios expected in terrestrial 
dust grains.

"Mickey Mouse" and other colonies of small microbes appear to be 
out of the ordinary.  These are fluffy white objects, about 1 
micron wide and resembling cotton balls.

"Here's the shocker," said Hoover, pointing at the ESEM monitor, 
"these small coccoid bodies are covered with all this incredible 
fibrous structure." The filaments appear to be about 30 to 40 
nanometers wide (that's about 1/10th a wavelength of visible 
light).

"It's difficult for me to say what it is," Abyzov said, "but I 
tend to agree that this is biological."

"There are all sorts of microorganisms in the ice.  Some are 
readily recognizable as cyanobacteria, bacteria, fungi, spores, 
pollen grains, and diatoms, but some are not recognizable as 
anything we've ever seen before," Hoover said.  Many will turn out 
to be known.  It's just that they look different under the ESEM, 
which provides details that are not available through other 
microscopes.

Familiar items include bits of sponge and feather, and diatom 
fragments, Hoover's other area of personal interest and expertise 
(he works at Marshall as an X-ray astronomer).  They have also 
found a number of large cyanobacteria with nanobacteria attached.

"What is clearly going on is that when microorganisms freeze, they 
shut down and go into this anabiotic state," Hoover explained.  
Anabiotic means alive but inactive, like suspended animation.  
Russian scientists have been able to revive and culture bacteria, 
yeast, fungi, and other microbes found in ice cores.

"One of the things that was really exciting was that many of the 
cyanobacteria from 1,243 meters down had lots of antimony," Hoover 
said.  The X-ray spectrum showed carbon, oxygen, zinc, silicon, 
aluminum, and potassium - all chemicals common to life.  But it 
also showed an abnormal amount of antimony, a toxic heavy metal.

"It was not just one of these that had it," Hoover said, "but 
microorganism after microorganism."

Gregory Jerman, the ESEM operator, noted that the metal content 
has varied with depth.  At some levels the microorganisms show 
large quantities of antimony, while in others zinc rings the bell

With more than 150 ESEM images and almost as many spectra 
recorded, Hoover and Abyzov next go to the Jet Propulsion 
Laboratory in Pasadena, California.  There, Dr. Ken Nealson will 
try to extract genetic material from the microorganisms.

As Hoover talked, another new image appeared on screen.

"It's pretty big," he said of an object that looked like a 
porpoise and probably is a protozoan.

"The work of identifying and classifying everything in the ice 
will be long and challenging," Hoover said.  He compared it to his 
own initiation in the world of diatoms where for years everything 
looked new until he became familiar with it.  Then he could 
quickly recognize the rare unusual specimen.

"It's necessary to know what to look for and the kinds of things 
you can see," he said.

Like the Klingon's forehead, a wrinkled object resembling a 
character from Star Trek, or the porpoise.  For now some of them 
just have nicknames, until Hoover, Abyzov, and their colleagues 
analyze their exciting images and obtain more definitive 
identifications of these microscopic beasts of the frozen 
underworld.

[To see the images mentioned in this article, see 
http://www.ssl.msfc.nasa.gov/newhome/headlines/ast12mar98_1.htm]

Author:  Dave Dooling
Curator:  Linda Porter
NASA Official:  Gregory S.  Wilson
------------------------------------------------------------------

MORE EVIDENCE POINTS TO IMPACT AS DINOSAUR KILLER
JPL release

12 March, 1998

Two new impact crater sites in Belize and Mexico add further 
evidence to the hypothesis that an asteroid or comet collided with 
Earth about 65 million years ago, subsequently killing off the 
dinosaurs and many other species on the planet.

Researchers Adriana Ocampo of NASA's Jet Propulsion Laboratory 
(JPL), Pasadena, CA, and Kevin Pope of Geo Eco Arc Research, La 
Canada-Flintridge, CA, led an international team that discovered 
the two new sites during a recent expedition sponsored by NASA's 
Exobiology Program and The Planetary Society, Pasadena, CA.

"We discovered an important new site in Alvaro Obregon, Mexico, 
about 230 kilometers (140 miles) from the rim of the Chicxulub 
crater.  This crater was formed when a 10 to 14 kilometer diameter 
(6 to 8 mile) asteroid or comet collided with Earth," Ocampo said.

"The site contains two layers of material, or ejecta, thrown out 
by the impact that flowed across the surface like a thick fluid, 
known as fluidized ejecta lobes," added Pope.  "This is the 
closest surface exposure of ejecta to the Chicxulub crater that 
has yet been found and the best example known on Earth from a 
really big impact crater."

Centered on the coast of Yucatan, Mexico, the Chicxulub crater is 
estimated to be about 200 kilometers (120 miles) in diameter.  The 
impact 65 million years ago kicked up a global cloud of dust and 
sulfur gases that blocked sunlight from penetrating through the 
atmosphere and sent Earth into a decade of near-freezing 
temperatures.  The drop in temperature and related environmental 
effects are thought to have brought about the demise of the 
dinosaurs and about 75 percent of the other species on Earth.

The Earth orbits the Sun in a swarm of so-called near-Earth 
objects, whether they are comets or asteroids, yet the science of 
detecting and tracking them is still relatively young.  Only a 
handful of astronomers around the world search for these objects, 
and they estimate that currently only about one-tenth of the 
population of near-Earth objects has been detected.  Chicxulub is 
the only impact event that has been correlated with mass 
extinctions to date.  The site has been dated geologically to the 
boundary between the Cretaceous and Tertiary
periods, also known as the K/T boundary.

Local geologist Brian Holland of Punta Gorda, Belize, guided the 
expedition to another new ejecta site about 480 kilometers (290 
miles) from the crater rim.  This Belize site contains tiny 
spheres of altered green glass, called tektites.  Tektites are 
rocks that have been melted to glass by the severe heat of an 
impact.  Expedition member Jan Smit of Free University, Amsterdam, 
noted that the Belize tektites were similar to those found in 
Haiti and northern Mexico.  This finding links the stratigraphy of 
the Belize sites to the more distant Caribbean and Mexican ejecta 
sites.

Alfred Fischer of the University of Southern California, Michael 
Gibson of the University of Tennessee at Martin, and Jaime Urrutia 
and Francisco Vega of the National Autonomous University of Mexico 
helped the team collect 400 kilograms (900 pounds) of samples, 
including drill cores, for paleomagnetic studies.  They also 
collected fossils from the site to help date the deposits and add 
new pieces to the puzzle of what happened at Chicxulub 65 million 
years ago.

Impact ejecta is very rare on Earth, but covers much of the 
surface of Mars because Mars' surface has remained stable and 
unchanged for billions of years, thus preserving debris from these 
rare impact events.  Also, such fluidized ejecta lobes have never 
been observed directly on Earth before and can serve as an 
excellent laboratory for studying the ejecta lobes surrounding 
many Martian craters.

"The discovery of these new ejecta sites is very exciting," said 
team co-leader Ocampo.  "It is like seeing a bit of Mars on 
Earth."

The exact nature of these ejecta lobes on Mars remains a mystery, 
Ocampo noted.  Some scientists think they were created by an 
abundance of water in the Martian crust, which turned the ejecta 
into a muddy, molasses-like material.  Others suggest the 
fluidized ejecta lobes were enabled by a much thicker atmosphere 
in Mars' early history.  As flying ejecta from an impact event 
flew through the Martian atmosphere, it was reduced by friction to 
a very dense, turbulent cloud of debris that also flowed like 
water.  Study of the Chicxulub fluidized ejecta may help settle 
this debate and shed new light on theories that the Martian 
surface may once have been more hospitable for life.

Volunteers who assisted The Planetary Society and the scientists 
in the field have posted their photographs of the expedition on 
The Planetary Society web site at the following URL:  
http://planetary.org.

Information about and images of newly discovered near-Earth 
objects found by JPL's ongoing Near-Earth Asteroid Tracking (NEAT) 
program are available at 
http://huey.jpl.nasa.gov/~spravdo/neat.html.

Ocampo and Pope's research was funded in part by the Exobiology 
Program of NASA's Office of Space Science, Washington, DC.  NASA's 
Jet Propulsion Laboratory is a division of the California 
Institute of Technology, Pasadena, CA.
------------------------------------------------------------------

ASTEROID WILL MISS EARTH BY "COMFORTABLE DISTANCE" IN 2028
JPL release

12 March, 1998

Asteroid 1997 XF11 will pass well beyond the Moon's distance from 
Earth in October 2028 with a zero probability of impacting the 
planet, according to astronomers at NASA's Jet Propulsion 
Laboratory, Pasadena, CA.

The asteroid "is predicted to pass at a rather comfortable 
distance of about 600,000 miles (about 960,000 kilometers) in 
2028," reported Dr. Donald K. Yeomans and Dr. Paul W. Chodas, JPL 
scientists who specialize in computing the predicted orbits of 
comets, asteroids, planets and other bodies in the solar system.

Data on the asteroid from March 1990 (well before its discovery in 
December 1997) was integrated into the orbit calculations by 
Yeomans and Chodas to arrive at the distance the asteroid will 
pass Earth.  The 1990 observations of the object were found today 
in the Palomar Planet Crossing Asteroid Survey conducted at 
Caltech's Palomar Observatory, by JPL's Eleanor Helin and Ken 
Lawrence and by Brian Roman, formerly of JPL.

Even prior to the discovery of the earlier Palomar observations, 
however, Yeomans and Chodas had determined that the impact 
probability would be zero.  The new calculations further 
underscore that conclusion, they said.  JPL is a division of the 
California Institute of Technology.
------------------------------------------------------------------

FLIGHT TEAM MAKES FINAL ATTEMPT TO CONTACT PATHFINDER LANDER
JPL note

9 March, 1998

The Mars Pathfinder flight team will make its final attempt to 
contact the spacecraft tomorrow using NASA's Deep Space Network 
34-meter antenna at Goldstone, CA.

Project representative Ben Toyashima will be the "ace," or primary 
flight controller, listening for a signal from the spacecraft.  
One-way light time from Earth to Mars is currently 19 minutes, 30 
seconds, so a two-way signal could be received in about 40 
minutes.  If no signal is detected within the first hour of the 
pass, Toyashima will send a set of commands to activate the 
spacecraft's thumbnail-size auxiliary transmitter, located on the 
top of the lander's base petal.  Although the flight team is not 
optimistic that a signal will be received, they would see a brief 
blip on the computer monitor if the spacecraft is still operating.  
Mars Pathfinder fell silent on September 27, 1997, which was the 
83rd day of surface operations, after having nearly tripled its 
design lifetime of 30 days.
------------------------------------------------------------------

MARS PATHFINDER UPDATE
JPL release

10 March, 1998

Today starting at 10:00 AM PST we will make our final attempt to 
contact Pathfinder.

10:15 AM - The high efficiency 34 meter Deep Space Network (DSN 
Station #15) antenna located in Goldstone California is currently 
attempting to lock onto a carrier signal using a Block 5 receiver.  
Mars is currently 2.35 Astronomical Units (AU), or 351 million 
kilometers away from Earth.  The one way light time is 19.8 
minutes.  The first command will be sent at 10:51 AM PST

10:39 AM - At 10:51 AM PST we will send a command to Pathfinder to 
activate an onboard sequence designed to turn on the primary 
Pathfinder transmitter.  Since the one way light time is 19.8 
minutes, we will have to wait for approximately 40 minutes before 
we can expect a response from Pathfinder, assuming the command was 
received and the sequence activated.

10:53 AM - The command to activate the onboard sequence is now 
being radiated to Pathfinder.

11:22 AM - We are now waiting to receive the signal.  Mars is 
currently 49.2 degrees above the horizon at the Goldstone DSN 
station located in the Mojave desert in southern California.

11:35 AM - We should have heard the signal by now, but we have 
not.  We will sweep for the carrier for 50 minutes.
------------------------------------------------------------------

MARS PATHFINDER MISSION STATUS
JPL release

10 March, 1998

The long goodbye to NASA's Mars Pathfinder lander and the 
Soujourner rover ended today when the lander failed to respond to 
the final command to communicate with controllers at NASA's Jet 
Propulsion Laboratory.  The Pathfinder mission, which operated 
three times longer than its original 30-day planned lifetime on 
the martian surface, is acknowledged as one of NASA's most 
successful endeavors as a dramatic example of the space agency's 
new style of "faster, better, cheaper" planetary exploration.

Today's last-ditch effort to listen for a signal from Pathfinder 
effectively ends the mission, said project manager Brian Muirhead.  
No further attempts will be made to communicate with Pathfinder, 
he added.

Pathfinder flight controllers Ben Toyoshima and Rob Smith at JPL 
spent nearly four hours today alternately commanding the lander to 
turn on its transmitter, then listening for a response via NASA's 
Deep Space Network's 34-meter antenna at Goldstone, California, in 
the Mojave Desert.  One-way radio communications to Mars from 
Earth take nearly 20 minutes.

The final Pathfinder telecommunications session ended at 1:21 p.m.  
PST when no transmissions had been detected from Pathfinder.  A 
description of the efforts to reestablish contact with Pathfinder 
can bee found at the following URL:
http://mars.jpl.nasa.gov/readme.html
------------------------------------------------------------------

STARDUST STATUS REPORT
by Ken Atkins, Stardust Project Manager

6 March, 1998

The Assembly, Test, and Launch Operations (ATLO) activities 
continued to make progress.  The Telecom subsystem interface tests 
with the system were completed; work proceeded on commanding with 
the ground support equipment, and testing of compatibility with 
the Deep Space Network (DSN) was initiated.

The assembly of the flight Sample Return Capsule (SRC) is nearing 
completion.  The avionics package was installed.  And ballast was 
added to increase the entry stability margin.  This brings the 
capsule to 45 kg.

The SRC Structural Model was returned to Denver from the Utah Test 
and Training Range.  The recorded data showed an extremely soft 
(21 g) landing in the drop test.

The Inertial Measurement Unit (IMU) chassis seal review and 
assessment of the torque of the connector screws was completed.  
This resulted in agreement to proceed with installation of 
electronics for the dry o-ring leak test.  Thermal vacuum testing 
of the spacecraft test battery was completed indicating acceptable 
temperature gradients.  Random vibration with control on the test 
battery was also completed and qualified the composite bulkheads.

In other news, Ambient temperature solar array deployment tests 
were completed on the qualification unit.  Electromagnetic testing 
was completed on the Power Control Assembly (PCA).  Random 
vibration and 2 axes of shock testing of the flight Command and 
Data Handling (C&DH) subsystem has been completed.  The Block 
Dictionary and Flight Rules and Constraints were also published.

For more information on the STARDUST mission--the first ever comet 
sample return mission--please visit the STARDUST home page:  
http://stardust.jpl.nasa.gov/
------------------------------------------------------------------

NEW MARS GLOBAL SURVEYOR IMAGES
JPL release

7 March, 1998

http://mars.jpl.nasa.gov/mgs/msss/camera/images/3_9_98_release/ind
ex.html

Mission Update

As of March 7, 1998, the Mars Global Surveyor spacecraft has 
completed 163 orbits of Mars, during which it has reduced its 
orbital period from 45 to 13.75 hrs.  The local time at the 
equator of the orbit is now roughly 11 AM.  The spacecraft remains 
healthy and operating normally.  Following the Mars Surveyor 
Operations Project's Delta-Critical Design Review the first week 
of March, the Project is now preparing to complete the first phase 
of aerobraking, raising the periapsis out of the atmosphere to 
suspend aerobraking until early September 1998.  The planned 
orbital period (11.6 hr) should be reached around the end of 
March.  At that time, the spacecraft will be placed in what is 
called the Science Phasing Orbit (or SPO), and enter a period that 
consists of three phases:

* SPO-1 (early April to early May 1998), when science data will be 
collected from roughly 10:45 to 10:00 AM local Mars time,

* Conjunction (roughly the month of May 1998), when the spacecraft 
will be placed in a quiescent state while the orbit of Mars moves 
behind the sun as seen from the Earth and communications become 
more difficult, and

* SPO-2 (early June through early September 1998), when more 
science data will be acquired, at between 9:00 and 6:00 AM.

For more information about the spacecraft and mission, visit the 
Mars Global Surveyor Project Web Site.

Camera Update

The Mars Orbiter Camera was turned off in mid-February, when the 
orbital period of the MGS spacecraft became too short to support 
both the playback of science data and the engineering activities 
associated with aerobraking.  Although there is a low probability 
of any harm coming to the instrument while we are not receiving 
data from it, we felt it prudent to turn the camera off when not 
using it.  This allowed us to turn on the heaters used to protect 
the instrument from getting too cold.  Typical average 
temperatures within the camera rose from very near their coldest 
limits to as much as 20 degrees C (36 degrees F) warmer...  what 
we call "nice and toasty."  Preparations to resume imaging in 
early April are now underway.

Malin Space Science Systems and the California Institute of 
Technology built the MOC using spare hardware from the Mars 
Observer mission.  MSSS operates the camera from its facilities in 
San Diego, CA.  The Jet Propulsion Laboratory's Mars Surveyor 
Operations Project operates the Mars Global Surveyor spacecraft 
with its industrial partner, Lockheed Martin Astronautics, from 
facilities in Pasadena, CA and Denver, CO.
------------------------------------------------------------------

GALILEO EUROPA MISSION STATUS
JPL release

11 March, 1998

NASA's Galileo spacecraft is once again sending pictures and 
science information to Earth following a 2-1/2 week-hiatus caused 
by a period of "solar conjunction." Radio communications were 
hampered during this period, when the Sun passed between Earth and 
Galileo.

Now that full communications have been re-established, Galileo is 
sending to Earth pictures and information stored on its onboard 
tape recorder during the close Europa flyby this past December.  
Included are observations of the Pwyll impact crater region, the 
Conamara Chaos region, and fields and particles information on 
Europa's interaction with Jupiter's magnetic and electric fields.

This batch of information was actually transmitted once before, 
but this retransmission of the recorded data allows scientists to 
fill gaps caused by transmission problems, and to replay 
particularly interesting observations and additional data.

A turn for attitude maintenance was performed successfully on 
Sat., March 7.  On Tues., March 10, the spacecraft's attitude 
control system was tested.  This test was designed to determine 
how Galileo was affected by intense radiation exposure during the 
February 10 Europa flyby.  Intense radiation in the Jovian system 
is considered a prime candidate as a cause of recent anomalous 
behavior by an attitude control system gyroscope.  After analyzing 
results of the test, it was determined that the gyro's performance 
had degraded further.  Although this may affect future pointing 
accuracy and stability, the Galileo team believes strongly that 
spacecraft still can collect additional science information during 
future flybys.

Later this week, the spacecraft will perform a flight path 
adjustment to ensure that it is aimed correctly for its next 
encounter with Europa, scheduled for March 29.
------------------------------------------------------------------

RAINFOREST MAPPING TECHNIQUES HIGHLIGHTED IN JPL EVENING TALK
JPL release

11 March, 1998

"Mapping the Amazon:  Science, Supercomputers and Synthetic 
Aperture Radar" will be the subject of a free public lecture on 
Thursday, March 19 at 7 p.m.  in JPL's von Karman Auditorium, 4800 
Oak Grove Dr., Pasadena.  Seating is limited and will be on a 
first-come, first-served basis.

The lecture will be presented by Dr. Anthony Freeman, Radar 
Instrument Manager for NASA's planned LightSAR mission.  Freeman 
was manager of the Spaceborne Imaging Radar-C (SIR-C) Outreach 
Program from 1994-96, and was recently involved with the discovery 
of evidence of a prehistoric civilization and remnants of ancient 
temples in Angkor, Cambodia, using the JPL-developed Airborne 
Synthetic Aperture Radar (AIRSAR).

Scientists studying global climate change search for evidence of 
carbon, either released as carbon monoxide and methane, or stored 
in plant biomass in rainforest regions sometimes known as the 
"lungs" of the Earth.  Using
sophisticated supercomputers and synthetic aperture radar (called 
"SAR"), scientists are now developing large-scale models of the 
carbon exchange occurring over the world's rain forests.  SAR is 
an imaging technique that uses radar to "see" objects under thick 
cloud and surface cover and at night.  It was used in the early 
1990s on the Magellan mission, penetrating Venus' thick clouds 
providing detailed images of that planet's surface, and onboard 
the Space Shuttle Endeavour in 1994, allowing archaeologists to 
locate ancient Arabia's "lost" city of Ubar by revealing old 
caravan routes buried beneath the region's thick layer of sand.

A SAR instrument onboard the Japanese JERS-1 satellite is now 
involved in the Global Rain Forest Mapping project, begun in 1995, 
to systematically map the world's tropical rain forests to better 
form models of global carbon exchange.  The first result from that 
project is a new map of the entire Amazon basin, available on the 
internet at http://southport.jpl.nasa.gov/amazon.

Working in conjuction with the SAR investigations are a host of 
sophisticated supercomputers, capable of multi-dimensional 
mathematical modeling which allows the extensive computations a 
product such as the newly-created Amazon map requires.  The new 
map will be used by scientists to estimate the area subject to 
deforestation and the extent of the Amazon's annual flooding.  
These estimations are contributing to models of carbon exhange 
that are being developed for the Amazon as part of NASA's Mission 
to Planet Earth program.

This lecture is part of the von Karman Lecture Series sponsored 
monthly by the JPL Media Relations Office.  A web site on the 
lecture series is located at http://www.jpl.nasa.gov/lecture.  For 
directions and other information, call the Media Relations Office 
at (818) 354-5011.  JPL is a division of the California 
Instititute of Technology.
------------------------------------------------------------------

End Marsbugs Vol. 5, No. 7

