- (Reuters) -- Detailed analysis of Martian soil samples
taken by the Spirit rover has confirmed much that scientists already knew
but has posed other puzzles about the geologic history of the red planet,
mission scientists said.
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- "Mars is not going to give up its secrets easily.
It is going to take a lot of time," Steve Squyres, the mission's principal
investigator, said.
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- Soil samples taken by complex instruments on the six-wheeled
robot Spirit last week showed large amounts of silicon and iron, and smaller
amounts of sulfur, chlorine, calcium and nickel on the surface of the Gusev
Crater - a barren, wind-swept basin that scientists believe may have been
the site of an ancient lake bed once fed by a Martian river.
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- The findings largely confirm the basic pattern of elements
revealed by previous NASA missions to Mars but scientists were surprised
to find olivine - a mineral normally found in volcanic rocks and speculated
that the sample surface soil could be ground up lava.
-
- Mr Squyres said scientists were also puzzled by what
he called a "chemical glue" that was holding the fine grains
of reddish soil together in minuscule clumps.
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- Mr Squyres and other mission scientists at the earth-bound
Jet Propulsion Laboratory (JPL) in Pasadena said they expected that the
fine grains of soil would give way under the pressure of the Spirit's robotic
instruments but "nothing collapsed".
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- "These grains hung together - What is the force
holding them together?" Mr Squyres said.
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- Mr Squyres said the first surface particles examined
by Spirit may have been blown in from other parts of Mars by the planet's
dust storms or by other phenomena.
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- However, Spirit's instruments can sample soil well below
the surface which should give scientists more clues as to the planet's
geologic origins and the burning question of whether the climate on Mars
was ever wet or warm enough to sustain some form of life.
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- Spirit was spending examining its first Martian rock
- a smooth pyramid-shaped rock dubbed Adirondack.
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- The rover extended its instrument arm onto the rock to
take measurements but mission members are still debating whether to drill
into the rock, which is about the size of a football and which scientists
believe was spewed onto the surface of Mars hundreds of millions of years
ago by a volcano.
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- Mr Squyres said it was still too early in the planned
three-month mission to speculate on whether there was once life-sustaining
water on Mars despite previous evidence of ice caps on the planet.
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- "It is really too early to say ... I don't think
there is any question there was once a lake in the Gusev Crater,"
he said.
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- "But as I said, Mars is not going to give up its
secrets easily, and finding those elements is going to take the full capabilities
of this vehicle," he said.
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- © 2004 Australian Broadcasting Corporation
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- http://www.abc.net.au/news/newsitems/s1028892.htm
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