Lump spotted on Mars might be ice - or stone

Less than a week after landing safely on a cold, sunny patch of far northern Mars, NASA's Phoenix lander is at work and one of its cameras, scientist said Friday, has already detected a lump of ice - or maybe only a little Martian rock.

Either way, the Phoenix will begin digging up and analyzing Martian material, perhaps next week, in its search for ancient water and organic chemicals that might point to signs of long-ago life.

On the same day the Phoenix find was announced, however, some spoilers from Harvard and Stony Brook universities reported in the journal Science that a study of earlier findings by the veteran Mars rover Opportunity, exploring near the Martian equator, shows that any water left from the planet's early days billions of years ago would have been far too salty to have sustained any form of life known on Earth.

The Phoenix team is running the experiments aboard the spacecraft from the University of Arizona's control center in Tucson. The spacecraft was guided to a spectacular landing last Sunday by engineers and scientists at the Jet Propulsion Laboratory in Pasadena.