The US Mars rover Opportunity has found evidence that the surface of Mars was once "drenched" with water, NASA scientists announced Tuesday.
The rover has been working on part of the Red Planet "where liquid water once drenched the surface," said Ed Weiler, NASA's associate administrator, at a news conference.
"NASA launched the Mars Exploration Rover mission specifically to check whether at least one part of Mars had a persistently wet environment that could possibly have been hospitable to life. Today we have strong evidence for an exciting answer: Yes," said James Garvin, a leading NASA scientist.
A layered rock studied by the robot detected evidence of sulfates and other minerals that form in the presence of water. However, no traces of living organisms have been discovered.
The Opportunity mission to the Mars began in January and is expected to continue its probe of looking for sings of life until April.