Did mile-deep canyon swallow Mars Polar Lander? Nobody knows

PASADENA - The vanished Mars Polar Lander could have tumbled down a canyon on the Red Planet, but investigators so far have uncovered no evidence supporting a single explanation for the disaster, NASA said today.

The $165 million lander was supposed to touch down Dec. 3 for a 90-day mission to analyze the planet's atmosphere and search for frozen water beneath its south pole. It has not been heard from since it started its descent after an 11-month cruise.

Members of the Lockheed Martin team that operated the craft believe it landed on the edge of a canyon nearly a mile deep and six miles wide, The Denver Post reported today, citing an unidentified Lockheed source who was on the mission team.

Nobody has ruled out the possibility of a rough landing - or any other scenario, such as a failure of the descent system or an explosion before entry, said Richard Zurek, the lander's project scientist at NASA's Jet Propulsion Laboratory.

"There are hazards in the area where we expected the lander to go down," he said today. "But it's by no means conclusive that that's the cause of us not being able to communicate with the lander."

The canyon covers roughly 10 percent of the selected landing site, a 1,500-square-mile ellipse near Mars' south pole.

"We don't know where it went," said Douglas Isbell, a NASA spokesman. "I'm not aware of any new information that would tell us that that area is more likely than the other areas. We were happy with our prelanding assessment, and we knew there were a few hazards, but nothing that we considered mission-threatening."

Lockheed scientists who steered the craft under JPL direction were surprised to learn that the canyon was inside the lander's projected landing zone, the Post said.

Joan Underwood, a Lockheed Martin spokeswoman, said today the company has not made any conclusions about the cause of the failure.