Is there life on Mars? While recent evidence indicates ancient water may once have supported life on the red planet, our search for E.T. has come up dry.
Of course, that hasn't stopped folks from trolling through photos taken by NASA rovers and probes -- spotting objects that look like faces, bones, and various critters.
Psychologists say the human brain is hard-wired to look for patterns, meaning, and even faces in images -- it's a phenomenon called pareidolia.
Want to experience a little off-planet pareidolia firsthand? Scroll down to see 11 "alien" objects spotted on Mars in recent months, and decide for yourself if you're looking at real signs of intelligent life...
...or just rocks.