Looking back: The solar panel and robotic arm of NASA's Phoenix lander, with a sample of soil in the scoop. The image was taken on the 16th Martian day after landing.
Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University
SYDNEY: NASA's has lost radio contact with its Phoenix Mars lander after a five-month mission. As autumn sets in, the polar probe has failed to capture enough sunlight to charge its batteries and power instruments.
Mission engineers said today that the last time they received a signal was mid-last week. Despite this, they report that the mission exceeded its planned life of three months to conduct experiments and beam back data.
"Phoenix provided an important step to spur the hope that we can show Mars was once habitable and possibly supported life," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington.
Successful mission
In addition to shorter days, Phoenix has encountered a dustier sky, more clouds and colder temperatures as the summer of Mars' northern hemisphere comes to an end.
The project team will be listening carefully during the next few weeks to hear if Phoenix revives and phones home. However, engineers now believe that is unlikely because of the worsening weather conditions on Mars.
While the spacecraft's work has ended, the analysis of data it beamed back has only just begun.
"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 at the University of Arizona in Tucson.
Launched in August 2007, Phoenix landed on 25 May 2008, farther north than any previous spacecraft to land on the Martian surface. The lander dug, scooped, baked, sniffed and tasted the Red Planet's soil (see, After shakin', Phoenix ready to bake, Cosmos Online).
Martian microbes
Among early results, it verified the presence of water-ice in the Martian subsurface, which NASA's Mars Odyssey orbiter first detected remotely in 2002. Phoenix's cameras also returned more than 25,000 pictures from sweeping vistas to near the atomic level using the first atomic force microscope ever used outside Earth.
"Phoenix not only met the tremendous challenge of landing safely, it accomplished scientific investigations on 149 of its 152 Martian days," said Phoenix Project Manager Barry Goldstein at NASA's Jet Propulsion Laboratory in Pasadena, California.
Phoenix's major role was to gather data on whether the environment of the Martian arctic has ever been favourable for microbes. But additional findings include documenting a mildly alkaline soil environment; finding small concentrations of salts that could be nutrients for life; discovering perchlorate salt, which has implications for ice and soil properties; and finding calcium carbonate, a marker of effects of liquid water.
Other notable results included observations of Martian haze, clouds, frost, whirlwinds and even snow descending from clouds (see, Robot lander detects snow falling on Mars, Cosmos Online). The probe also succeeded in co-ordinating with NASA's Mars Reconnaissance Orbiter to perform simultaneous ground and orbital observations of Martian weather.
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