Since the dawn of the telescopic age and even now in the age of robotic probes, people have been finding "evidence" of alien civilization on the planet Mars. With even a simple telescope, the Martian polar ice caps can be distinctly seen as can regions of darker and lighter features. As telescopic technology improved, more details could be discerned. Unfortunately, the human mind has the ability to see things that aren’t actually there, a phenomenon known as pareidolia.
Visit Mars with Curiosity and Kim Stanley Robinson
One of the most amazing things about the images coming to us from the Mars Science Laboratory Curiosity rover is that the scenery looks oddly familiar. One NASA scientist remarked that Gale Crater was reminiscent of the American West. Having lived in the Intermountain West, I concur. Take a look for yourself with this interactive 360 degree panorama of Curiosity’s surroundings.