PASADENA, Calif. — The landing site of the Mars rover Curiosity was once covered with fast-moving and possibly waist-high water that could have possibly supported life, NASA scientists announced Thursday.
While planetary scientists have often speculated that the now-desiccated surface of Mars was once wet, Curiosity cameras provided the first proof that flowing water was present on a least one part of Mars for “a long time.”
The early finding led Mars Science Laboratory mission top scientist John Grotzinger to conclude that Curiosity had found a potentially “habitable” site — a central goal of the mission — well before heading to its primary destination.
He said the area needed to be studied far more extensively but that “a long-flowing stream can be a habitable environment. We’re still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment.”
Curiosity team scientists determined that flowing water was once present near the Gale Crater landing site based on the telltale size, shape and scattering of pebbles and gravel nearby.
The roundedness of the pebbles is especially significant, they said, and strongly suggests that the rocks were carried down a roughly 25-mile stream or river and were smoothed along the way.
William Dietrich, professor of geomorphology and member of the Curiosity imaging science team, presented some rounded earthly pebbles, which he said are similar to those in the images.
“Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them,” Dietrich said. “This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”
Curiosity made its dramatic landing in early August, and it has spent much of its time since testing out systems and instruments and preparing for its two-year drive.
But the rover’s suite of cameras began sending back images soon after landing, and they provided sufficiently detailed pictures to convince scientists that the pebbles and gravel had a watery past.