Copyright © 1998 Nando.net
Copyright © 1998 Reuters News Service
BOSTON (May 27, 1998 7:20 p.m. EDT http://www.nando.net) - A Martian mineral
deposit 300 miles wide may contain clues to one of astronomy's persistent
puzzles: Did the planet once sustain life? A huge deposit of the mineral
hematite has led to speculation that there was water on Mars long enough
for life to
form, according to a scientist at an American Geophysical Union meeting
in Boston on Wednesday.
The hematite deposit "is really the first evidence we have that hot
water was around ... long enough for a geological period of time so that
potentially life
could have had an opportunity to form," Arizona State University Professor
Phil Christensen told reporters.
Hematite is an iron oxide mineral that forms by a variety of ways that
often involve water. On Earth, the coarse-grained hematite spotted on Mars
occurs
around volcanic regions such as Yellowstone National Park. It is evidence
that a large scale hydrothermal system operated beneath the Martian surface,
said the scientists working on the Mars Global Surveyor Mission.
"If you want to find out about possible life on Mars, the deposit is
a good place to start," Christensen said. "You've got water, you've got
heat, got energy.
It's a good place if you want to have life."
Dr. David Smith of NASA's Goddard Space Flight Center said a laser altimeter
aboard the satellite orbiting above Mars mapped the topography and in April
discovered new information about the planet's north polar cap and its
surrounding features, including dune fields that share similar properties
to North
Africa's sand dunes.
The instrument also revealed the presence of high altitude clouds above
the polar cap. Now in the midst of winter, the polar cap has expanded.
"We want to
watch it closely during the summer -- another 18 months or so -- to
see what happens to both the cap and the clouds," Smith said.
Another researcher, Michael Malin, whose company makes cameras for NASA's
Mars mission, displayed a new composite photograph of a crater 25 miles
wide and 1 mile to 1.5 miles deep about 3,600 miles south of the Martian
equator. The deep, dark area near the middle of the crater appeared to
be a
frozen pond and there was evidence of seepage as well, Smith said.
"It's like a dry lake," he said.
The scientists are trying to determine what Mars was like 3 billion years ago and that is where the evidence of water and mineral deposits come into play.
"Because the minerals were formed a long time ago, they're evidence
of what the environment was like a long time ago," Christensen said. "We're
expecting
to find more. This is really just the tip of the iceberg."
By Leslie Gevirtz, Reuters