[meteorite-list] NASA's Mars Rover Opportunity Begins Study of Martian Crater

[Ron Baalke]

Sept. 1, 2011

Dwayne Brown      
Headquarters, Washington                      
202-358-1726 
dwayne.c.brown at nasa.gov 

Guy Webster 
Jet Propulsion Laboratory, Pasadena, Calif. 
818-354-6278 
guy.webster at jpl.nasa.gov 
RELEASE: 11-284

NASA'S MARS ROVER OPPORTUNITY BEGINS STUDY OF MARTIAN CRATER

WASHINGTON - The initial work of NASA's Mars rover Opportunity at its 
new location on Mars shows surface compositional differences from 
anything the robot has studied in its first 7.5 years of exploration. 

Opportunity arrived three weeks ago at the rim of a 14-mile-wide 
(22-kilometer-wide) crater named Endeavour. The first rock it 
examined is flat-topped and about the size of a footstool. It was 
apparently excavated by an impact that dug a crater the size of a 
tennis court into the crater's rim. The rock was informally named 
"Tisdale 2." 

"This is different from any rock ever seen on Mars," said Steve 
Squyres, principal investigator for Opportunity at Cornell University 
in Ithaca, N.Y. "It has a composition similar to some volcanic rocks, 
but there's much more zinc and bromine than we've typically seen. We 
are getting confirmation that reaching Endeavour really has given us 
the equivalent of a second landing site for Opportunity." 

The diversity of fragments in Tisdale 2 could be a prelude to other 
minerals Opportunity might find at Endeavour. In the past two weeks, 
researchers have used an instrument on the rover's robotic arm to 
identify elements at several spots on Tisdale 2. Scientists have also 
examined the rock using the rover's microscopic imager and multiple 
filters of its panoramic camera. 

Observations by Mars orbiters suggest that rock exposures on 
Endeavour's rim date from early in Martian history and include clay 
minerals that form in less-acidic wet conditions, possibly more 
favorable for life. Discontinuous ridges are all that remains of the 
ancient crater's rim. The ridge at the section of the rim where 
Opportunity arrived is named "Cape York." A gap between Cape York and 
the next rim fragment to the south is called "Botany Bay." 

"On the final traverses to Cape York, we saw ragged outcrops at Botany 
Bay unlike anything Opportunity has seen so far, and a bench around 
the edge of Cape York looks like sedimentary rock that's been cut and 
filled with veins of material possibly delivered by water," said Ray 
Arvidson, the rover's deputy principal investigator at Washington 
University in St. Louis. "We made an explicit decision to examine 
ancient rocks of Cape York first." 

The science team selected Endeavour as Opportunity's long-term 
destination after the rover climbed out of Victoria crater three 
years ago this week. The mission spent two years studying Victoria, 
which is about one twenty-fifth as wide as Endeavour. Layers of 
bedrock exposed at Victoria and other locations Opportunity has 
visited share a sulfate-rich composition linked to an ancient era 
when acidic water was present. Opportunity drove about 13 miles (21 
kilometers) from Victoria to reach Endeavour. It has driven 20.8 
miles (33.5 kilometers) since landing on Mars. 

"We have a very senior rover in good health for having already worked 
30 times longer than planned," said John Callas, project manager for 
Opportunity at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, 
Calif. "However, at any time, we could lose a critical component on 
an essential rover system, and the mission would be over. Or, we 
might still be using this rover's capabilities beneficially for 
years. There are miles of exciting geology to explore at Endeavour 
crater." 

Opportunity and its rover twin, Spirit, completed three-month prime 
missions in April 2004 and continued working for years of extended 
missions. Both have made important discoveries about wet environments 
on ancient Mars that may have been favorable for supporting microbial 
life. Spirit ended communications in March 2010. 

"This is like having a brand new landing site for our veteran rover," 
said Dave Lavery, program executive for NASA's Mars Exploration 
Rovers at NASA Headquarters in Washington. "It is a remarkable bonus 
that comes from being able to rove on Mars with well-built hardware 
that lasts." 

NASA will launch its next-generation Mars rover, Curiosity, between 
Nov. 25 and Dec. 18, 2011. It will land on Mars in August 2012. JPL 
manages the Mars Exploration Rover Project for NASA's Science Mission 
Directorate in Washington. 

For more about Opportunity, visit: 

http://www.nasa.gov/rovers 
	
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