Pasadena, Calif. -- NASA engineers in California set the Phoenix Mars Lander on a course toward the Red Planet's north polar region with a flight adjustment Thursday.
Phoenix is scheduled to set down on Mars May 25. The tentative site is a broad valley nicknamed the "Green Valley."
The final decision will be made after the Mars Reconnaissance Orbiter gets more images of the area.
Researchers have mapped 5 million rocks around the landing site that would be big enough to end the mission if Phoenix hits them.
The area was selected because of the possibility of finding microbial life there.
"Our landing area has the largest concentration of ice on Mars outside of the polar caps. If you want to search for a habitable zone in the arctic permafrost, then this is the place to go," said Peter Smith, principal investigator for the mission, at the University of Arizona, Tucson.
Phoenix is to dig down into the permafrost to search for signs of life.
Copyright 2008 by United Press International.