September 30, 2008

NASA Extends Phoenix Lander Mission

NASA announced on Monday it was extending the Mars Phoenix lander's mission, saying it will operate until it dies in the cold, dark Martian winter.

Since it was dropped onto the Martian surface in May, the Phoenix lander has already operated far longer than expected and its controllers said they would squeeze every drop of life they could out of the solar-powered lander.

The lander found evidence that the chemical makeup of the dust on the surface of Mars resembles that of sea water, adding to evidence that liquid water that once may have supported life flowed on the planet's surface.

Barry Goldstein, Phoenix project manager at the Jet Propulsion Laboratory in Pasadena, California, told reporters they are literally trying to make hay as the sun shines.

The lander has already operated for more than 120 Martian days, known as sols, but it was scheduled to last just 90.

However, the sun will soon dip below the horizon until April. Already the lander is getting less power, after a summer of light-filled days akin to the months of daylight at Earth's poles in the summer.

The Phoenix team reported definitive proof of water after the lander scraped up ice In July. It also found perchlorate, a chemical compound used by plants and microbes and it has sent back the first image of a speck of red Martian dust taken through an atomic force microscope.

William Boynton, who leads a team operating the lander's Thermal and Evolved-Gas Analyzer at the University of Arizona, said the latest analysis shows evidence of a carbonate chemical, likely calcium carbonate, best known as limestone.

And further analysis shows the Martian dust is about as alkaline as seawater, with a pH of 8.3, more evidence that life could have existed on Mars, said JPL's Michael Hecht.

The lander has seen snow, frost and clouds forming, according to Mars weatherman Jim Whiteway of the University of Toronto. "This is now occurring every night," he said -- although it is not yet clear whether any snow reaches the surface.

"Mars wobbles more than Earth does as it spins, so sometimes its poles point directly at the Sun," said Peter Smith, Phoenix principal investigator at the University of Arizona. They would be warmer then, perhaps warm enough to melt ice that Phoenix has confirmed lies just below the red dust.

"If you were to sweep away this thin soil layer on what looks like this flat plain you would find it is more like a skating rink," Smith said.

"Is this a habitable zone on Mars? I think we are approaching this hypothesis," he added.

The scientists plan to turn on a microphone that was supposed to record the lander's descent in May but did not, Smith said. "We are going to try and turn on this microphone and try to listen to Mars for the first time," he said.


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Mars Phoenix Mission