Washinton - A group of scientists who worked on the Phoenix
Mars lander last year say they have found evidence of liquid salt
water on the red planet.
An analysis of photographs from the lander that explored Mars for
six months shows drops of what could be salty, liquid water on the
legs of the lander.
They believe the droplets were kicked up from just below the
planet's surface when Phoenix landed in May and say they grew and
merged over time much as water particles would do.
The findings are to be presented in a report, The Physical and
Thermodynamic Evidence for Liquid Water on Mars, at an astronomy
conference in Texas on Monday.
'A large number of independent physical and thermodynamical
evidence shows that saline water may actually be common on Mars,'
said the report's chief author, University of Michigan professor
Nilton Renno. 'Liquid water is an essential ingredient for life. This
discovery has important implications to many areas of planetary
exploration, including the habitability of Mars.'
But the evidence is controversial even among scientists who worked
on the mission and was never raised by NASA at the time, with some
saying there were other more probable explanations. Still 22
scientists have signed onto the report.
Phoenix did confirm the existence of ice on Mars to much fanfare
and in the past researchers believed that was the only type of water
likely to be found on the planet, where temperatures average about
negative 60 degrees Celsius at the rover's landing site.
Renno, a co-investigator on the Phoenix mission, said another
discovery by Phoenix - the presence of perchlorate salts - is
consistent with liquid water.
The salts could significantly lower the freezing point of water to
between negative 67 and negative 75 degrees - much as salt is used in
cold climates on Earth to melt ice and snow. Renno said there could
be areas across the planet that are too salty to freeze.
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