[meteorite-list] NASA Rover Nears Martian Victoria Bowl Goal

[Ron Baalke]

Sept. 6, 2006

Dwayne Brown/Erica Hupp 
Headquarters, Washington 
202-358-1726/1237

Guy Webster 
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6278 

RELEASE: 06-307

NASA ROVER NEARS MARTIAN VICTORIA BOWL GOAL

NASA's Mars rover Opportunity is closing in on what may be the 
grandest overlook and richest science trove of its long mission. 

During the next two weeks, the robotic geologist is likely to reach 
the rim of a hole in the Martian surface wider and deeper than any it 
has visited. The crater, known as "Victoria," is approximately 
one-half mile wide and 230 feet deep. 

Images from NASA's Mars Global Surveyor orbiter show the crater walls 
expose a stack of rock layers approximately 100 to 130 feet thick. 
Opportunity will send back its initial view into the crater as soon 
as it gets to the rim. Scientists and engineers will use 
Opportunity's observations from points around the rim to plot the 
best route for entering the crater. 

"Victoria has been our destination for more than half the mission," 
said Ray Arvidson of Washington University, St. Louis. Arvidson is 
deputy principal investigator for Opportunity and its twin rover, 
Spirit. "Examination of the rocks exposed in the walls of the crater 
will greatly increase our understanding of past conditions on Mars 
and the role of water. In particular, we are very interested in 
whether the rocks continue to show evidence for having been formed in 
shallow lakes." 

The NASA rovers have been exploring landscapes on opposite sides of 
Mars since January 2003. Their prime missions lasted three months. 
Both are still investigating Mars' rocks, soils and atmosphere after 
more than 30 months. Opportunity works in a region where rock layers 
hundreds of yards in thickness cover older, heavily cratered terrain. 

"We have a fully functional vehicle with all the instruments working. 
We're ready to hit Victoria with everything we've got," said Byron 
Jones, a rover mission manager at NASA's Jet Propulsion Laboratory, 
Pasadena, Calif. 

Though it's still winter in Mars' southern hemisphere, days have begun 
getting longer again, and Opportunity's power supply from its solar 
panels is increasing daily. During its first two months on Mars, 
Opportunity examined a one-foot stack of rock layers at its landing 
site inside "Eagle Crater" and found geological evidence that water 
had flowed across the surface long ago. 

The rover spent the next nine months driving to and exploring a larger 
crater, "Endurance." There it examined a stack of exposed layers 23 
feet thick. Over the drive from Endurance to Victoria, the rocks tell 
a history of shallow lakes, drier periods of shifting dunes and 
groundwater levels that rose and fell. Minerals indicate the ancient 
water was very acidic. 

The much thicker stack of revealed rock layers at Victoria beckons. 
Arvidson said, "We want to examine the thick section of rocks exposed 
on the walls in Victoria crater to understand whether the environment 
that produced these materials was similar to the environment recorded 
in the rocks that we have seen so far. Is there a record of a 
different type of deposition? Was there a wet environment that was 
less acidic, perhaps even more habitable? Where do the layers from 
Endurance fit in this thicker sequence?" 

NASA's Mars Reconnaissance Orbiter reached Mars in March 2006. It will 
begin its primary science phase in November, offering higher 
resolution images and mineral mapping than have been possible with 
previous orbiters. 

Victoria will be one target for the orbiter. "By combining the data 
from Opportunity and Mars Reconnaissance Orbiter, we'll be able to do 
some fantastic coordinated analysis," Arvidson said. Such analysis 
will enhance the science return of both missions and aid in 
interpreting orbiter data taken of potential landing sites for future 
missions elsewhere on Mars. 

"It's an amazing accomplishment that Spirit and Opportunity have 
completed the equivalent of 10 prime missions," said John Callas, 
rover project manager at JPL. "Each of them shows some signs of 
aging, though. We can't say how long the rovers will last, but we 
will push to get the best possible science out of these national 
treasures as long as they keep operating. Victoria could very well be 
the most productive and exciting science of the entire mission." 

JPL manages the rovers and the Mars Reconnaissance Orbiter for NASA's 
Science Mission Directorate. For rover images and information, visit: 

http://www.nasa.gov/rovers
	
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