PHOENIX - Sharp new images received Saturday from the Phoenix lander largely convinced scientists that the spacecraft's thrusters had uncovered a large patch of ice just below the Martian surface.

That bodes well for the mission's main goal of digging for ice that can be tested for evidence of organic compounds that are the chemical building blocks of life.

Team members had said Friday that photos showing the ground beneath the lander suggested the vehicle was resting on splotches of ice.

Washington University scientist Ray Arvidson said the spacecraft's thrusters may have blown away dirt covering the ice when the robot landed one week ago.

On Saturday, scientists said a more detailed image taken under the lander shows one of the craft's three legs sitting on coarse dirt and a large patch of what appears to be ice -- possibly a metre in diameter -- that apparently had been covered by a thin layer of dirt.

Peter Smith, a University of Arizona scientist who is the chief project investigator, says scientists were worried that it may be 30-, 40-, 50-centimetres deep, which would be a lot of work.