Phoenix lander discovers evidence of water on Mars in Martian soil

Liquid water is required by all species on Earth and we've assumed that
water is the very least that would be necessary for life on Mars,

Phoenix landed on Mars on May 25 on a three-month hunt to determine
if it could support life. It is conducting experiments to learn whether
the ice ever melted in the red planet's history that could have led to
a more hospitable environment. It is also searching for the elusive
organic-based compounds essential for simple life forms to emerge.

The
ice confirmation earlier this week was accidental. After two failed
attempts to deliver ice-rich soil to one of Phoenix's eight lab ovens,
researchers decided to collect pure soil instead. Surprisingly, the
sample was mixed with a little bit of ice, said Boynton, who heads the
oven instrument.

Researchers were able to prove the soil had ice
in it because it melted in the oven at 32 degrees — the melting point
of ice — and released water molecules. Plans called for baking the soil
at even higher temperatures next week to sniff for carbon-based
compounds.NASA said Phoenix has achieved minimum success thus far. The space
agency on Thursday announced that it would extend the mission for an
extra five weeks until the end of September, adding $2 million more to
the $420 million price tag, said Michael Meyer, Mars chief scientist at
NASA headquarters.

Now the mission has been extended through September 30 to allow the
lander to analyze that water ice and soil for signs of organic
materials and for conditions suitable for life, NASA announced.

The additional five weeks of operation will cost some two million U.S. dollars.

Principal investigator Peter Smith, of the University of
Arizona, reported that all of Phoenix's instruments are healthy. A
troublesome short circuit problem appears to have been resolved.

"We're going to complete the science that we set out to complete," he
said of the mission's extended time. "But we have lots more to explore
within reach of our robotic arm."

Water Appears To Have Been Too Salty

 

Together with co-authors Andrew H. Knoll and Scott M. McLennan,
Tosca analyzed salt deposits in four-billion-year-old Martian rock
explored by NASA's Mars Exploration Rover, Opportunity, and by orbiting
spacecraft. It was the Mars Rover whose reports back to Earth stoked
excitement over water on the ancient surface of the Red Planet.

The new analysis suggests that even billions of years ago, when
there was unquestionably some water on Mars, its salinity commonly
exceeded the levels in which terrestrial life can arise, survive, or
thrive.

People have known for hundreds of years that salt prevents microbial
growth," Tosca says. "It's why meat was salted in the days before
refrigeration."

Tosca and Knoll say it's possible there may have been more dilute
waters earlier in Mars' history, or elsewhere on the planet. However,
the area whose rocks they studied -- called Meridiani Planum -- is
believed, based on Mars Rover data, to have been one of the wetter,
more hospitable areas of ancient Mars.