Subject:   PUBLIC INVITED TO BROWSE 20,000 NEW ADDITIONS
                     TO MARS PHOTO GALLERY
Date: Mon, 22 May 2000 15:40:12 -0400 (EDT)
From: NASANews@hq.nasa.gov
To:

Donald Savage
Headquarters, Washington, DC                                                           May 22, 2000
(Phone:  202/358-1727)

Mary Hardin
Jet Propulsion Laboratory, Pasadena, CA
(Phone:  818/354-0344)

Dr. Ken Edgett
Malin Space Science Systems, San Diego, CA
(Phone:  858/552-2650 x500)

RELEASE:  00-82

PUBLIC INVITED TO BROWSE 20,000 NEW ADDITIONS TO MARS PHOTO GALLERY

     More than 20,000 new images of the planet Mars taken by
 NASA's Mars Global Surveyor spacecraft are now available in a
 web-based photo album -- the single largest one-time release
 of images for any planet in the history of solar system
 exploration.

     The 'picture postcard' scenes in the new images reveal the
 Red Planet, often said to be the most Earth-like planet, as an
 alien, bizarre and puzzling world.

     "These are exciting times for Mars scientists and this
release of images is in my opinion something unprecedented in
the Mars science business," said Dr. Ken Edgett, staff scientist
at Malin Space Science Systems, San Diego, CA.  "People everywhere
with Internet access will be able to take their own personal
journey of exploration and discover Mars via these pictures.
They can experience them the same way that Mars Global Surveyor
scientists do -- one at a time, no captions or explanations, just
'Here it is. What does it show me?'"


     The archive of images now covers a period that spans one Mars
year (687 Earth days),beginning in September 1997 with pictures
taken during the aerobraking phase and extending through August
1999 when Global Surveyor was well into its mapping mission.Many
of the pictures have such high resolution that objects on the
surface the size of a school bus can be seen.


     According to the Mars Orbiter Camera imaging team, placing
these images within NASA's Planetary Data System for archiving is
an important step in the Mars Global Surveyor mission that permits
the public to examine the original data and make discoveries
"for themselves." -more--2-

     "Putting these data into perspective is very difficult.
 We have focused on 'themes.'Layers on the Martian surface are 
the biggest 'theme' or 'finding' of the imaging investigation
so far. To a geologist, layers record history and they are the
most geologically important,profound thing we have seen," said Dr.
Michael Malin, principal investigator for the camera system at
Malin Space Science Systems. "We see layers in the walls of
canyons, craters, and troughs. We see layers in both the north
and south polar regions. We see them in the craters on top of
volcanoes, we see them in pits at the bottoms of impact craters,
we see them virtually everywhere that some process has exposed
the subsurface so that we can see it from above."


     "Seeing Mars up close through the narrow angle camera has
been a humbling experience. We often find surfaces for which 
there are no obvious analogs on Earth, like certain ridges that
look like dunes. Our terrestrial geologic experience seems, at
times, to fail us," Edgett said. "Perhaps it is because water
is the dominant force of erosion on Earth, even in the driest
desert regions. But on Mars that force of change may have been
something else, like wind. The ridges seen in places like the
Valles Marineris floors are strange. They aren't dunes because
they occur too close together, their crests are too sharp, their
slopes too symmetrical. They often appear to be a specific layer
of material that has undergone erosion -- we just wish we knew
what processes are involved that cause this kind of erosion."


     The camera system uses a "push-broom" technique that
systematically builds up pictures of the surface directly below
one line at a time as the spacecraft orbits Mars.  The wide-angle
lens provides a complete low-resolution global map of the planet
every day showing surface features and clouds at a resolution
of about 4.6 miles (7.5 kilometers).  The narrow-angle telescope
takes close-up pictures of small areas with a resolution of 
about 5 feet (1.5 meters).  Because of the extremely high data
volume of the high-resolution images, controllers cannot use
this mode continuously. Instead, they painstakingly plan which
 areas they want to target.


     Mars Global Surveyor was launched on November 7, 1996 and
arrived at Mars on September 12, 1997.  The spacecraft has made
more than 5,000 orbits of and has been systematically mapping
the Red Planet since March 1999.


     Mars Global Surveyor is managed by the Jet Propulsion
Laboratory for NASA's Office of Space Science, Washington, DC.
The camera system was built and is operated by Malin Space
Science Systems, San Diego, CA. JPL's industrial partner is
Lockheed Martin Astronautics, Denver, CO, which developed and
operates the spacecraft. JPL is a division of the California
Institute of Technology, Pasadena, CA.
         - end -

NOTE TO EDITORS:  The archive of images can be found at:
http://www.msss.com/moc_gallery/
A subset of the images can be seen at:

http://photojournal.jpl.nasa.gov/new   
http://mars.jpl.nasa.gov/mgs

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