Mars rover's search for life-friendly habitats heads to mountain
* Journey to Mount Sharp will take from 10 months to a year
* At least three stops for scientific studies are planned
* Rock layers might show how wet planet became dry desert
By Irene Klotz
CAPE CANAVERAL, Fla., June 5 (Reuters) - NASA's Mars rover Curiosity is on the road toward Mount Sharp, the primary target of a planned two-year mission to search for habitats that could have supported life, officials said on Wednesday.
Ten months ago the rover landed inside a giant impact basin near the planet's equator, a site selected because of the 3-mile-high (5-km-high) mound of layered rock rising from the crater floor.
Instead of heading directly to Mount Sharp, scientists wanted to explore an area in the opposite direction where images from orbit showed three different types of rocks coming together.
Curiosity drilled out a sample from a slab of bedrock and immediately hit pay dirt. The analysis showed it contained six elements needed for microbial life - hydrogen, carbon, oxygen, nitrogen, sulfur and phosphorus - plus water that had not been too acidic or too salty.
After a month's hiatus due to a communications blockage by the sun, Curiosity last month drove about nine feet (2.7 meters) and drilled into a second mudstone. Analysis of that sample is pending, deputy project scientist Joy Crisp from NASA's Jet Propulsion Laboratory in Pasadena, California, told reporters on a conference call on Wednesday.
On Monday, scientists sent commands for the rover to turn around and begin driving toward the base of Mount Sharp, located about five miles (eight km) southwest of its present position.
It will be a slow and circuitous journey. At least three stops for science studies are planned, including measurements to determine how much drier the region gets as Curiosity moves away from the low-lying Yellowknife Bay where it conducted its early investigations.
"We're going to keep our eyes open as we drive and if we in fact drive past something that's amazing, we might actually turn around and go back and check it out, but there's nothing that we see from orbit that's like some super-compelling clue to life or something like that," Crisp said.
"What we have is a real desire to get to Mount Sharp," she added.
What lures scientists to the mountain is a mineral map, compiled by orbital reconnaissance, showing chemical variations from base to summit. Scientists believe the mineral changes reflect and record transitions in Mars' environment from a warm and wet past to the cold, dry desert that appears today.
"It's like looking at layers of the Grand Canyon," Crisp said.
The older layers of the planet are at the base of Mount Sharp. Rocks at higher elevations contain chemical information about later climates.
"We're trying to read the record in the rocks to figure out what the environment was like when those rocks were forming," Crisp added.
Even by the most direct route with minimal stops, Curiosity's drive to the base of Mount Sharp will take 10 months to a year, said project manager Jim Erickson from the Jet Propulsion Laboratory.
That doesn't leave much time for mountain climbing and analysis during the rover's primary two-year mission, but with its early discoveries at Yellowknife Bay, Curiosity already has answered the key question about whether Mars was suitable for microbial life.
NASA's other operational Mars rover, Opportunity, which was designed to last three months, has been working for more than nine years.
(Reporting by Irene Klotz; Editing by Jane Sutton and Eric Beech)