NASA extends Phoenix mission as snow falls on Mars

[Guest guest]

http://news.yahoo.com/s/nm/20080929/sc_nm/us_mars_phoenix & printer=1;_ylt=AnIiacO\

NLlbKaqgigfyqroQiANEA

NASA extends Phoenix mission as snow falls on Mars

By Maggie Fox, Health and Science Editor1 hour, 28 minutes ago

NASA extended the mission of the busy Phoenix lander Monday, saying it

will operate the lander until it dies in the cold and dark of the

Martian winter.

It is already snowing there, above the equivalent of the Arctic circle

on Mars, the researchers said.

The explorer found evidence that the dust on the surface of Mars

resembles seawater in its chemical makeup, adding to evidence that

liquid water that once may have supported life flowed on the planet's

surface.

The Phoenix lander already has operated far longer than expected when

it was dropped onto the Martian surface in May, and its controllers

said they would squeeze every drop of life they could out of the

solar-powered lander.

" We are literally trying to make hay as the sun shines, " Barry

Goldstein, Phoenix project manager at the Jet Propulsion Laboratory in

Pasadena, California, told reporters.

Scheduled to last just 90 Martian days, known as sols, the lander has

already operated for more than 120.

But soon the sun will dip below the horizon until next April. Already

the lander is getting less power, after a summer of light-filled days

that resemble the months of daylight enjoyed at the Earth's poles in

the summer.

Mars weatherman Jim Whiteway of York University in Toronto, Canada,

said the lander has seen snow, frost and clouds forming as the

atmosphere cools, although the snow is vaporizing before reaching the

ground.

" Nothing like this view has ever been seen on Mars, " Whiteway said.

" We'll be looking for signs that the snow may even reach the ground. "

LET IT SNOW

Scientists had known it likely snowed on Mars but the lander got

unique measurements showing it happening in real time.

The lander has already gathered more evidence of water on the surface

of the now-dry planet. In July, the Phoenix team reported definitive

proof that water exists on Mars after the lander scraped up ice, and

it also found perchlorate -- a chemical compound sometimes used by

plants and microbes.

It also sent back the first-ever image of a speck of red Martian dust

taken through an atomic force microscope.

The latest analysis shows evidence of a carbonate chemical, likely

calcium carbonate -- best known as limestone, said Boynton,

who leads a team that operates the lander's Thermal and Evolved-Gas

Analyzer at the University of Arizona.

And, said JPL's Hecht, further analysis shows the Martian dust

is about as alkaline as seawater, with a pH of 8.3. This provides more

evidence that life could have existed on Mars.

, Phoenix principal investigator at the University of

Arizona, said Mars wobbles more than Earth does as it spins, so

sometimes the poles are pointed directly at the sun. They would be

warmer at those times, perhaps warm enough to melt the 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, "

said.

" Is this a habitable zone on Mars? I think we are approaching this

hypothesis, " he added.

said the scientists plan to turn on a microphone that was

supposed to record the lander's descent in May but which failed to do

so. " We are going to try and turn on this microphone and try to listen

to Mars for the first time, " he said.

(Editing by Will Dunham and Vicki )

Copyright © 2008 Reuters Limited. All rights reserved. Republication

or redistribution of Reuters content is expressly prohibited without

the prior written consent of Reuters. Reuters shall not be liable for

any errors or delays in the content, or for any actions taken in

reliance thereon.

Copyright © 2008 Yahoo! Inc. All rights reserved.