November 11, 2008 The approaching Martian winter has spelled an end to the pioneering Phoenix Mars Lander mission. More than five months after reaching the red planet, the lander sent what is expected to be its final transmission back to Earth on November 2, exceeding its planned operational life-span by two months.

Increased cloud, dust and the onset of colder temperatures mean that the robot is no longer receiving enough sunlight to charge its batteries and although engineers will keep the airwaves open, further communication with the lander is not expected.

"Phoenix not only met the tremendous challenge of landing safely, it accomplished scientific investigations on 149 of its 152 Martian days as a result of dedicated work by a talented team," said Phoenix Project Manager Barry Goldstein at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The process of analyzing data collected by Phoenix is still in its early stages, but early results have already verified the presence of water-ice in the Martian subsurface, revealed a mildly alkaline soil environment, found small concentrations of salts that could be nutrients for life, and discovered calcium carbonate, a marker of effects of liquid water.

Phoenix also observed snow descending from clouds, provided unprecedented data on the Martian weather and returned more than 25,000 pictures, including those produced by the first atomic force microscope ever used outside Earth.

"Phoenix has given us some surprises, and I'm confident we will be pulling more gems from this trove of data for years to come," said Phoenix Principal Investigator Peter Smith of the University of Arizona in Tucson.

Further reading and images are available at the NASA site.

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