Mars Rover Discoveries Point to Planet's
Origins
NASA scientists are excitedly speculating that discoveries made
by a Mars rover over the weekend will help them finally unravel
whether water played a role in the Red Planet's geologic history, a
science team member said on Monday.
Scientists were pouring over data and microscopic images
returned to Earth by the rover Opportunity, which spent the weekend
examining a multilayered rock nicknamed El Capitan embedded in the
side of the small crater where Opportunity landed on Jan. 24. The
rover has yet to climb out of the small crater onto the flat
Meridiani Planum to examine a large deposit of what may be
water-formed hematite. The science team planned to command the
rover to use a rock scraping tool to clear away dust so that its
spectrometers can get clearer readings of El Capitan, which lies in
an outcrop of bedrock that scientists believe holds the key to the
planet's past.
"There are high expectations that we will understand the extent
to which the outcrop has been modified chemically and whether water
was involved," Ray Arvidson, deputy principal investigator, said.
Arvidson said scientists are working on competing theories about
how the fine layers in the 3 foot-high outcrop were formed, and
hoped to have preliminary findings within days.
"One idea is that it's associated with ash fall or simply
windblown material that was compacted," he said. "Or it's
associated with (sedimentation in) an old lake or shallow sea. The
hope is in the end you have the information to show how they were
formed and modified."
On the other side of the planet, Opportunity's twin, Spirit,
left the trench it dug and spent days examining, and rolled toward
Bonneville Crater, about 328 feet from its landing site in Gusev
Crater -- a massive depression the size of the U.S. state of
Connecticut. Preliminary data showed that the soil at the sides and
bottom of the trench was "coherent" but scientists were not yet
sure what was holding the fine particles together, Arvidson
said.
Mission manager Rob Manning said Spirit spent its 49th Martian
day, or sol, wrapping up its work in the trench and driving 62 feet
toward an area nicknamed Middleground, about halfway between
Bonneville Crater and the rover's landing point. The boulder-strewn
landscape becomes more treacherous the closer Spirit gets to the
crater, which ejected boulders into the surrounding area when a
meteor slammed into it eons ago, Manning said.
"We may see craters launched off from well below Gusev crater
that may have had some contact with ancient water," Manning
said.