Chile desert combed for Mars clues

ESTACI YUNGAY, Chile - The Atacama desert may seem to contain little besides red-grey rocks and sand - but scientists are busy searching here for clues to life in a place it much resembles: Mars.

This desert in northern Chile, like the red planet, is hot, dusty and extremely dry.

Yet life exists here: tiny algae and bacteria that have evolved to survive in the parched earth on little more than sunlight.