BBC:
After just seven weeks of roaming the surface of Mars, NASA's
Curiosity rover has found evidence of ancient liquid water. The
robot has sent pictures of classic conglomerate rocks, made up
of gravel and sand, found on the planet's surface. One large
slab, named Hottah for a lake in Canada's Northwest
Territories, contains pebbles whose size and rounded shape
indicate they were transported and eroded in water. Researchers
think the rock was part of a network of ancient streams that
flowed several billion years ago. With further study, they hope
to determine the water's pH value and the speed and distance of
the water flowâmdash;and, ultimately, whether
such an environment could ever have supported microbial
life.
