Page last updated at 23:45 GMT, Tuesday, 24 March 2009

Briny pools 'may exist on Mars'

By Paul Rincon

Science reporter, BBC News, The Woodlands, Texas

The probe had surpassed its expected lifetime by more than two months

Pools of salty water might be able to exist just below the surface of Mars, planetary scientists believe.

Researchers previously thought water existed largely as ice or as vapour on Mars, because of the low temperatures and atmospheric pressure.

But Nasa's Phoenix lander has shown the presence in Martian soil of perchlorate salts, which can keep water liquid at temperatures of minus 70C.

Pockets of brine might form when soil interacted with ice.

Researchers have been discussing the idea at the 40th Lunar and Planetary Science Conference (LPSC), here in The Woodlands, Texas.

They were presenting some of the first scientific results from Phoenix, which touched down on Mars's northern plains on 25 May 2008.

"I do think those pools might exist. But there's still more to know about the properties of these perchlorate solutions, such as what their vapour pressure is," Dr Mike Hecht, from Nasa's Jet Propulsion Laboratory (JPL) in Pasadena, California, explained.

Full article here:

http://news.bbc.co.uk/2/hi/science/nature/7958471.stm