A hearing held by the House Science Committee that aimed to discuss the largest of NASA's upcoming projects — including launching another Mars rover in 2020 and a Europa flyby mission with a possible subsequent landing — took a strange turn when congressman Dana Rohrabacher, of California, asked "Is it possible that there was a civilization on Mars thousands of years ago?"
Kenneth Farley, a professor of geochemistry at the California Institute of Technology and project scientist for the 2020 rover team, answered: "there's no evidence that, uhh, I'm aware of [...] I would say that is extremely unlikely." Additionally, he corrected Rohrabacher's timeline by saying that "the evidence is that Mars was different billions of years ago. Not thousands of years ago."
Conditions on Mars could have been conducive to life in the past — scientists have found water on the red planet along with its atmosphere would have been more habitable before it was stripped by cosmic and solar winds. Recently, a team from the University of Arkansas has argued that even current conditions on the Red Planet could be capable of hosting microbial life.
The chances of our planetary neighbor ever hosting a civilization, however, are extremely small — although some, perhaps not entirely credible sources, claim that evidence of a previous sophisticated species can be found in photos released by the Curiosity Rover, which may show a six inch man who bares a startling similarity to the Atacama Alien found in Chile.