Mars water clues offer life search site

01:56, Jan 16 2013
A photo from Nasa's Curiosity Mars rover reveals clear signs of ancient water. The white arrows show mineral-filled veins and the black arrows mineral spheres, both of which require water to form.

The Curiosity rover has entered a Martian terrain offering clear signs of ancient water and tantalising hints of a scientific bonanza.

In a press teleconference today, Nasa rover team members reported the discovery of mineral-filled veins and small mineral spheres that require water to have once saturated the muddy floor of Gale crater.

But geologists are particularly enticed by the sedimentary rock that Curiosity has roved across on its way from its landing site.

As it descended deeper into the exposed strata and further back in geologic time, it first encountered pebbles and cobbles laid down in deep torrents of water, then sandy sediments deposited by less turbulent currents, and finally, fine and silty sediments.

The silty sediments speak of a far quieter time in Gale, perhaps when a placid lake filled the crater.

Lake sediments are the ideal place to look for organic matter lingering from ancient Martian life, which is what Curiosity will do when it begins rock drilling in a few weeks.