In its first chemical analysis of soil from Mars' northern plains, NASA's Phoenix lander has turned up no evidence of water, scientists said Monday.
Still, researchers remained confident that the craft is in the right place to uncover veins of ice believed to lie only inches beneath the surface.
A soil sample was cooked twice in one of Phoenix's eight ovens over the past few days, according to William Boynton, lead scientist for the Thermal and Evolved-Gas Analyzer. The first test reached 95 degrees Fahrenheit, while the second hit 350 degrees.
“Had there been any ice, it would have melted,” Boynton said. “We saw no water in the soil whatsoever.”
The instrument detected carbon dioxide, hardly a surprise since the thin Martian atmosphere is primarily made up of the gas.
The goal of the $420 million Phoenix mission is to find out whether Mars is, or ever was, suitable for rudimentary life forms. Phoenix landed near Mars' north pole May 25.
The science team at the University of Arizona and the Jet Propulsion Laboratory in La Canada-Flintridge, Calif., were not disappointed by the failure to turn up water on the first test sample. Phoenix's nearly 8-foot-long robotic arm has only dug into the soil between 2 inches and 3 inches. The ice layer, they said, is likely farther down.
The latest images of the trench from which the soil was taken show light-toned material that the scientists think could be ice protruding from the side of the trench.
“It looks like we clipped the edge of the top of a polygon,” said Ray Arvidson, a lead scientist.