(SPACE.com) -- Researchers can now say definitively that Mars once supported a watery environment, but whether the Red Planet could have ever supported life is still far from certain.

The success of NASA's Mars rover Opportunity in finding tell-tale signs of past water at its Meridiani Planum landing site has left some researchers believing the region could have once been a habitable, albeit still hostile, environment.

"We can say 'yeah, it was probably a habitable environment, but was it an environment in which life could have arisen,'" said Cornell University's Steve Squyres, principal science investigator for the Mars rover mission, in a telephone interview. "That's a good question."

While Opportunity has not found any signs of life since landing at Meridiani in January, knowing water was once abundant there makes it a good candidate for future study.

"In everything we know about life on Earth, there is no known example without liquid water," Squyres said. "That's the reason the search for water was so important at Mars."

http://www.cnn.com/2004/TECH/space/12/03/marschances.water/index.html