Tags:
Journalism of Courage
WASHINGTON, Dec 5: The Pathfinder robot uncovered evidence that Mars was once warm, moist and more like earth than its forbidding surface now suggests. “This is a shot in the arm for the possibility of finding evidence of life” on the red planet, says one researcher.
The body of evidence returned by Pathfinder are suggestive that “conditions had been conducive for the formation of life early in Mars’ history,” said Matt P Golombek, a Pathfinder mission scientist and lead author of a research report in the journal Science.
Golombek said that several lines of evidence have produced a strong consensus among scientists that Pathfinder landed on July 4 on a Martian plain that was sculpted by liquid water billions of years ago and that such water proves the planet once was a warmer, more life-friendly place.
Although Pathfinder and its faithful wheeled Rover, Sojourner, found no definite evidence of life, the report in Science said, “the spacecraft studies appear consistent with a water-rich planet that may be more earth-like than previously recognised, with a warmer and wetter past in which liquid water was stable and the atmosphere was thicker.”
“Finding evidence of liquid water,” a term used by scientists to differentiate from water in other forms it takes under various pressures and temperatures, is a shot in the arm for the possibility of finding evidence of life, said Golombek. “If there was no liquid water, then there would be no need to search for life on Mars.”
“There’s nothing we found that would preclude life on early Mars,” said John T Schofield of the Jet Propulsion Laboratory, the California Institute of Technology agency that controlled Pathfinder for NASA.
“Because there was liquid water billions of years ago, it is conceivable that there could have been life,” said H J Moore of the U S Geological survey, one of the principle researches with Sojourner. “The liquid water makes that a possibility.” Liquid water would mean that Mars was much warmer than the minus 100 degree temperatures experienced by Pathfinder, the researchers say in Science. This means that the atmosphere on Mars was then much thicker than it is now, researchers say.
Moore said that Sojourner, the small wheeled Rover that roamed for more than 170 feet around the landing site, found a number of rocks that bear a strong resemblance to rocks that on earth are formed in the presence of water.
He said rocks named Shark, Prince Charming and Ender all appear to be conglomerates, or rocks formed of smaller pebbles bound together by a matrix, such as clay. Such rocks are formed by water forces on earth, said Moore.
Some rocks also bore evidence that they may have been formed on a lake shore or even underwater, suggesting that water at one time possibly pooled on Mars, said Moore.
Moore said that a search for life will be a part of NASA’s continuing exploration of Mars, but he warns, “Mars is a big place and where would you go to look? it is a very tough question.”
“It’s unlikely that a search for life will turn up bones sticking out of Martian sand somewhere. More likely, any Martians that ever lived may have been microscopic,” he said.
Golombek said it is unlikely there will be final answers about Martian life until samples are returned from the red planet. And even then, finding evidence of life would be only a very remote possibility, he said.
