Phoenix prepares for life-on-Mars dig

Nasa’s Phoenix Mars Lander spent its first full day in the Martian arctic plains checking its instruments in preparation for an ambitious digging mission to study whether the site could have once been habitable.

The three-legged lander set down on Sunday in relatively flat terrain covered by fissures outlining polygon shapes. The geometric cracks are probably caused by the repeated freezing and thawing of buried ice.