BBC NEWS | Science/Nature | Ice lake found on the Red Planet:
"Ice lake found on the Red Planet
A disc of water ice in a Martian crater, ESA
The presence of water makes life a more likely possibility
A giant patch of frozen water has been pictured nestled within an unnamed impact crater on Mars.
The photographs were taken by the High Resolution Stereo Camera on board Mars Express, the European Space Agency probe which is exploring the planet.
The ice disc is located on Vastitas Borealis, a broad plain that covers much of Mars' far northern latitudes.
The existence of the water-ice patch on Mars raises the prospect that past or present life will one day be detected.
It also boosts the chances that manned missions could eventually be sent to the Red Planet - because they would probably need accessible water to survive."