- The Washington Times - Thursday, June 5, 2008

LOS ANGELES (AP) | NASA’s Phoenix lander was ordered Wednesday to begin its long-awaited exploration of Mars’ north pole region by clawing into the permafrost to search for evidence of the building blocks of life.

Scientists told the long-armed lander to dig the first of three shallow pits north of where it landed May 25. By the end of the week, it will dump the dirt into a tiny oven where it will be baked and studied.

Mission managers won’t know until Thursday how Phoenix fared on its first dig. Because the robot communicates with Earth through two Mars satellites, it has to wait until the end of the day when a satellite flies overhead to send back images and data.

The green light to scrape the Martian surface came after an extensive check of Phoenix’s 8-foot robotic arm and other scientific instruments. The lander is the first to settle in the northern latitudes to study whether the polar environment is capable of supporting primitive life.

“It’s absolutely an incredibly science-rich location,” said chief scientist Peter Smith of the University of Arizona, Tucson, who heads the three-month, $420 million mission.

Before the actual work, Phoenix had playtime in the Martian dirt, doing two practice runs that involved scooping up and then dumping out fistfuls of soil. The tests yielded an intriguing scientific find: In both cases, the loose soil was mixed with glints of white bits that scientists think is either surface ice or salt deposits.

Phoenix zeroed in on three sites to the right of the test dig area that scientists have playfully named Baby Bear, Mama Bear and Papa Bear after the Goldilocks fairy tale.

For the initial dig, scientists commanded the lander to cut into the Baby Bear site at an angle, dig three-tenths of an inch into the permafrost and drag the dirt into the arm’s scoop like a backhoe.

Then Phoenix will swing its robotic arm 90 degrees and wait for further instructions to drop the scoopful of dirt into a miniature oven designed to heat the sample and analyze the vapors for traces of organic compounds, said Ashitey Trebi-Ollennu, a robotic arm engineer with NASA’s Jet Propulsion Laboratory in Pasadena.

Although the oven’s spring-loaded doors did not fully open as scientists hoped, Mr. Smith said it should not be a problem. Over the next several days, Phoenix will scoop up soil from the other two sites for its microscope and wet chemistry lab to analyze.

Phoenix cannot detect fossils or living microbes. Instead, it will poke into the soil and ice to study whether liquid water ever existed and whether there are any organic compounds, those containing carbon and hydrogen atoms. Scientists generally agree that water, organics and a heat source are needed for a habitable environment.

Twin rovers that have been roaming near the Martian equator since 2004 have uncovered evidence that water once flowed at or near the surface of ancient Mars.

“We’re just taking an exploratory step here,” Mr. Smith said earlier this week. “Our instruments are not designed to decode DNA molecules … We’re looking for the basic ingredients that would allow life to prosper in this environment.”



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