Mars Soil Fit for Life, Tests Confirm

June 26, 2008 -- The Phoenix lander's first taste test of soil near Mars' north pole reveals a briny environment similar to what can be found in backyards on Earth, scientists said Thursday.

The finding raises hope that the Martian arctic plains could have conditions favorable for primitive life. Phoenix landed a month ago to study the habitability of Mars' northern latitudes.

"There's nothing about it that would preclude life. In fact, it seems very friendly," mission scientist Samuel Kounaves of Tufts University said of the soil. "There's nothing about it that's toxic."

Phoenix so far has not detected organic carbon, considered an essential building block of life. Last week, the lander found evidence of ice below the soil. Scientists generally agree that liquid water, a stable energy source and organic, or carbon-containing, compounds are required for a habitable zone.

The latest experiment was designed to test for minerals that do not have carbon in them. Earlier this week, Phoenix's 8-foot-long robotic arm delivered a pinch of dirt to its onboard lab.

Like a chemist, the spacecraft mixed the soil with water brought from Earth into a beaker the size of a teacup and stirred it. Sensors inside the beaker detect the soil's pH and probe for traces of the nutrients.