Scientists confirm water on Mars
Water definitely exists on Mars, scientists operating a probe that has been digging on the planet's surface confirmed.
The discovery made by the American space agency Nasa's Phoenix Mars Lander raises hopes of finding traces of life on the Red Planet.
The news scientists had been waiting for came after soil collected on Wednesday was tested in the craft's on-board laboratory.
Water vapour given off when the sample was heated was identified by a chemical analyser carried on Phoenix. The sample was scooped up from a 2in trench dug by the probe's robot arm.
Phoenix landed on Mars on May 25 in a region near the north pole where scientists suspected frozen water may lie a few inches under ground.
Dr William Boynton, from the University of Arizona in Tucson, lead scientist for Phoenix's thermal and evolved-gas analyser (Tega) instrument, said: "We have water. We've seen evidence for this water ice before in observations by the Mars Odyssey orbiter and in disappearing chunks observed by Phoenix last month, but this is the first time Martian water has been touched and tasted."
With such encouraging results, Nasa has decided to extend the original three month mission by five weeks. Two previous attempts to deliver icy soil to the lander's gas analyser failed when the samples became stuck inside the scoop. Only after Wednesday's sample had been exposed to the air for two days, allowing some of the water to evaporate, was it possible to carry out the test.
Principal investigator Dr Peter Smith, from the University of Arizona, said: "Mars is giving us some surprises. We're excited because surprises are where discoveries come from.
"One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck, different from what we expected from all the Mars simulation testing we've done. That has presented challenges for delivering samples, but we're finding ways to work with it and we're gathering lots of information to help us understand this soil."
A key question scientists want to answer is whether the ice ever thaws, because life needs liquid water to exist. The researchers have also been studying a panorama of colour images captured by Phoenix showing the surrounding landscape.
