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Mars Pathfinder Photographs Provide Geological Support For The Important Role That Liquid Water Has Played On Mars


News Service
Cornell University

Contact: Blaine P. Friedlander, Jr.
Office: (607) 255-3290
E-Mail: bpf2@cornell.edu

December 4, 1997

Pathfinder photographs provide geological support for the important role
that liquid water has played on Mars, scientists report today

ITHACA, N.Y. -- After studying more than 9,500 images taken during the
acclaimed Mars Pathfinder mission, scientists report in today's journal
Science (Dec. 5) that surface photographs provide strong geological and
geochemical evidence that fluid water was once present on the red planet.

"We now have geological evidence from the Martian surface supporting
theories based on previous pictures of Mars from orbit that water played
an important part in Martian geological history," said James F. Bell, Cornell
senior research associate in astronomy and a member of the Mars
Pathfinder imaging team.

Bell, along with lead author P. H. Smith of the University of Arizona;
Robert J. Sullivan Jr., Cornell research associate in planetary science; and
23 other scientists authored the paper, "Results from the Mars Pathfinder
Camera." The report is part of a complete Mars Pathfinder mission report
published in Science.

During the first 30 days of the Mars Pathfinder mission, the Imager for Mars
Pathfinder (IMP) returned 9,669 pictures of the surface. These pictures
appear to confirm that a giant flood left stones, cobbles and rocks
throughout Ares Vallis, the Pathfinder landing site. In addition to finding
evidence of water, the scientists confirmed that the soils are rich in iron,
and that suspended iron-rich dust particles permeate the Martian
atmosphere.

Bolstering their evidence for once-present water, the imaging team found
evidence for a mineral known as maghemite -- a very magnetic iron oxide.
Bell explained that maghemite forms in water-rich environments on Earth
and could likely be formed the same way on Mars. Bell explained that
reddish rocks like Barnacle Bill, Yogi and Whale rock show evidence of
extensive oxidation on their surfaces. He said the oxidation -- or the rusting
of the iron -- is possible only if water existed on the surface at some time
and played an important role in the geology and geochemistry of the planet.

But, where did all the water go?

"That's the golden question. No one knows," said Bell, explaining that
several theories about the disappearing water exist, such as evaporation
into space, or seepage into sub-surface ice deposits or liquid aquifers, or
storage at the Martian poles. Bell said that robotic missions to Mars early
in the next century, including a Cornell-led rover mission to be launched
in 2001, will attempt to determine the water's whereabouts, as well as to
determine whether the Martian environment may once have been more
conducive to life.

Mars Pathfinder's camera also revealed that Mars' atmosphere is more
dusty and dynamic than expected, Bell explained. Surprisingly, the
scientists found wispy, blue clouds, possibly composed of carbon dioxide
(dry ice), traveling through Mars' salmon-colored sky. White cirrus-like
clouds, made of icy water vapor, also circulate throughout the thin Martian
atmosphere.

"We were surprised to see such variations in the clouds, particularly since
Mars has such a thin atmosphere," Bell said. "We figured the atmosphere
would be the same everyday, but there is a lot of real weather occurring
there. It's a small atmosphere, but a vigorous one."

Looking at Martian rocks like Yogi, Barnacle Bill and Scooby Doo reveals
that the rocks have been sitting on the planet's surface for billions of
years, enduring a slow-motion sandblasting from a usually weak, dusty
Martian wind. To carve rock with such a weak wind force requires a vast
amount of time, Bell explained.

"The slow, persistent weathering and erosion of the rocks is like water
torture to the max," he said. "Mars really is an ancient world. We're still
trying to sort it all out."
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