[meteorite-list] Rover Arrives Safely at 'Home Plate'
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Feb 14 12:09:15 2006
Rover arrives safely at `Home Plate'
By ALICIA CHANG
February 14, 2006
LA CANADA FLINTRIDGE - The Mars rover Spirit has hit a home run by
landing in a rugged plateau dubbed "Home Plate," but scientists are
still trying to decipher its geology.
The six-wheeled Spirit reached the northern edge of the broad mesa last
week about four months after climbing down from a Martian hill as tall
as the Statue of Liberty. Scientists believe "Home Plate" - which stands
about 6 feet high - holds important geologic clues to the Red Planet's past.
So far, scientists say they are puzzled by what they have seen. Unlike
other areas of Gusev Crater that Spirit has analyzed, "Home Plate" is
made of highly layered rocks that are coarse at the bottom and fine at
"It's stunning ... by far the best layering we've ever seen at Gusev,"
principal investigator Steve Squyres of Cornell University recently
posted on his Web site.
Squyres said it's too early to say what the rocks are made of, or how it
fits into the Mars story.
Layered rocks can be formed several different ways, such as by a
volcanic eruption or impact crater. They also can be deposited there by
wind or water. Squyres said it appears that the rocks were formed from a
volcanic explosion, but more study is needed.
"The bottom line for now is that we've got a spectacular mystery in
front of us, and far more questions than we have answers," Squyres wrote.
Previous examination of the crater by Spirit reveals a violent history.
Three outcrops examined by the rover displayed deposits of water-altered
debris from explosive events. Scientists believe hot ash once fell from
the sky about 4 billion years ago. During that time, water was present,
but not a large amount.
Engineers plan to steer Spirit toward a rugged rock outcrop that
scientists have nicknamed "Gibson" after the baseball catcher Josh
Gibson. Engineers have not decided how long they intend to keep Spirit
Spirit and its twin, Opportunity, have been exploring opposite sides of
Mars since January 2004. The solar-powered robots, managed by NASA's Jet
Propulsion Laboratory, have outlasted their primary mission and are
working on overtime.
Received on Tue 14 Feb 2006 11:41:32 AM PST