[meteorite-list] NASA Opportunity Rover Finishes Walkabout On Mars Crater Rim

[Ron Baalke]

Dec. 4, 2012

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: 12-418

NASA OPPORTUNITY ROVER FINISHES WALKABOUT ON MARS CRATER RIM

SAN FRANCISCO -- The latest work assignment for NASA's long-lived Mars 
rover Opportunity is a further examination of an area where the robot 
just completed a walkabout. 

"If you are a geologist studying a site like this, one of the first 
things you do is walk the outcrop, and that's what we've done with 
Opportunity," said Steve Squyres, the mission's principal 
investigator at Cornell University in Ithaca, N.Y. 

Coming up on its ninth anniversary, Opportunity still is a capable 
robotic explorer. It has been investigating a crater-rim site where 
observations from orbiting Mars spacecraft detected traces of clay 
minerals, which form under wet, non-acidic conditions that can be 
favorable for life. The rover's current activities were presented at 
the Fall Meeting of the American Geophysical Union in San Francisco. 

The rover team chose this site as a driving destination years earlier. 
The site is named Matijevic Hill in honor of the late Jacob 
Matijevic, who led the engineering team for the twin Mars exploration 
rovers Spirit and Opportunity for several years. 

Opportunity drove about 1,160 feet (354 meters) in a counterclockwise 
circuit around Matijevic Hill in October and November, bringing the 
total miles driven on the mission to 22 miles (35.4 kilometers). 
Researchers used the rover to survey the extent of Matijevic Hill 
outcrops and identify the best places to investigate further. 

"We've got a list of questions posed by the observations so far," 
Squyres said. "We did this walkabout to determine the most efficient 
use of time to answer the questions. Now we have a good idea what 
we're dealing with, and we're ready to start the detailed work." 

The hill is on the western rim of Endeavour Crater, a bowl 14 miles 
(22 kilometers) in diameter. An impact from a celestial object dug 
this crater more than 3 billion years ago, pushing rocks onto the rim 
from a greater depth than Opportunity reached during its first 
several years on Mars. Since the impact, those rocks may have been 
altered by environmental conditions. Sorting out the relative ages of 
local outcrops is a key to understanding the area's environmental 
history. 

"Almost nine years into a mission planned to last for three months, 
Opportunity is fit and ready for driving, robotic-arm operations and 
communication with Earth," said the mission's deputy project 
scientist, Diana Blaney, of NASA's Jet Propulsion Laboratory (JPL) in 
Pasadena, Calif. 

Two outcrops of high interest on Matijevic Hill are "Whitewater Lake" 
and "Kirkwood." Whitewater Lake is light-toned material that science 
team members believe may contain clay. Kirkwood contains small 
spheres with composition, structure and distribution that differ from 
other iron-rich spherules, nicknamed blueberries, that Opportunity 
found at its landing site and throughout the Meridiani Planum area it 
has explored. Squyres calls the Kirkwood spheres "newberries." 

"We don't know yet whether Whitewood Lake and Kirkland are from before 
or after the crater formed," he said. "One of the most important 
things to work out is the order and position of the rock layers to 
tell us the relative ages. We also need more work on the composition 
of Whitewater and debris shed by Whitewater to understand the clay 
signature seen from orbit, and on the composition of the newberries 
to understand how they formed." 

NASA launched Spirit and Opportunity in 2003. Both completed their 
three-month prime missions in April 2004 with Spirit ceasing 
operations in 2010. The mission's goal is to learn about the history 
of wet environments on ancient Mars. JPL manages the Mars Exploration 
Rover Project for NASA's Science Mission Directorate at NASA 
Headquarters in Washington. 

For more information about Opportunity, visit 

http://www.nasa.gov/rovers 

You can follow the project on Twitter and on Facebook at: 

http://twitter.com/MarsRovers 

and 

http://www.facebook.com/mars.rovers 

-end-