Nasa scientists struggled yesterday to process the soil the Phoenix Mars Lander has scooped from the Red Planet's surface.
The Martian dirt is too clumpy to sift into the spacecraft's laboratory.
The scientists called it an important day last week when the Phoenix's robotic arm scraped its first,
cup-sized sample from the planet's surface.
Since then have been unable to get any of the clotted soil through a screen into the lander's "thermal evolved gas analyser".
"What we've found is although we had an awful lot of dirt break apart very few particles dropped into the instruments.
"We now at least know that the vibrator is functioning," said the man in charge of the analysis project, Dr William Boynton, of the University of Arizona.
"It looks like the soil is just too adhesive to make it through when it's put down as a mass."
He said if further attempts with a built-in vibrator failed to get enough dirt into the machine, the next step would be to try with a second scoop of soil, sprinkling a small amount on the screen to see if it would go through.
Boynton said the team was optimistic this technique would work, and was not ready to give up on the soil samples.
"It would be at least a week or two before we would start to get terribly concerned," he said. "We do have a number of things we're going to be trying."
The scientists don't know why the Martian dirt has proved so clumpy, saying the area under the lander could have got wet from the spacecraft's thrusters or melting ice, or that salts in the soil could act as a cementing agent.
The US$420 million ($554 million) lander spent 10 months journeying from Earth and touched down two weeks ago.
Its three-month mission was proposed after the Mars Odyssey detected frozen water below Mars' surface in 2002.
Scientists believe the Martian soil might contain salt left by evaporated water or ice, and hope to learn what minerals make up the soil.
- REUTERS
