Mars lander ready to do some digging

After troubleshooting an electrical problem on NASA's Phoenix lander and performing a test scoop into the crumbly surface of the Martian northern plain, scientists said Monday that they are ready to dig for ice as early as today.

Phoenix is the first spacecraft designed to sample the water on an alien planet. Over the weekend, it sent back images showing white streaks under the lander that could be surface ice.

Scientists were so excited that they nicknamed the site Holy Cow.

"It's a thrill for me to find out we're in a really great place to do the science we want to do," said Peter Smith of the University of Arizona, the lead scientist on the $420 million mission.

Even if the patches turn out to be a more common salt, scientists are certain large stores of ice lie just inches beneath the lander.

Scientists tested Phoenix's nearly 8-foot-long robotic arm by extending it to the ground, leaving an imprint that researchers dubbed Yeti (abominable snowman) because it resembles a large footprint. The arm also scooped up a bit of soil.

"The soil is crumbly," said Raymond E. Arvidson of Washington University in St. Louis during a briefing Monday morning from Tucson, Ariz. "It's kind of like cemented garden soil."

He said the robotic arm should not have any trouble. "When you push on it, it breaks apart. It's not going to be really strong stuff."