Scientists announced Thursday that waterâ€”fast-running and relatively deepâ€”once coursed over the now bone-dry surface, a finding based on the presence of rounded pebbles and gravel near the rover’s landing site in Gale Crater.
What’s more, the team has concluded that the water was present for “thousands or millions of years,” though the researchers said it would take far more research to get a clearer picture of the flow’s longevity.
The discovery is the first proof that surface water once ran on Mars. Planetary scientists have hypothesized that the cut canyons and riverlike beds photographed by Mars satellites had been created by running water, but only now do researchers have on-the-ground confirmationâ€”and the promise of learning much more about the nature and duration of the water flows.
“We’ve now identified pebbles and gravel at the landing site that clearly have been carried down by water, have been broken down and very much smoothed out,” said William Dietrich, a geomorphologist working with the Curiosity imaging science team. “This is the beginning of our process of learning how much water was running and how long this area was wet.”