The planet Mars has intrigued humans since we first began to study the sky. It is the only planet that looks red to the naked eye, which may explain why the ancient Greeks and Romans associated it with the bloody god of war. Spacecraft that visited Mars in the 1960s and 1970s found a freezing, arid, dead world. Nevertheless, the idea of life on Mars, and, in particular, intelligent life on Mars, fed by years of science fiction stories, persists in the public mind, despite the weight of scientific evidence against it.
Astronomers see it as a mere optical illusion, proof of the power of human imagination.
But a few, very vocal individuals see it as proof of an ancient Martian civilization. But the Face on Mars is not the first time humans have been misled about evidence for life on our neighboring planet. When early astronomers trained their crude telescopes on Mars, they could see few details of its surface beyond some dark patches and white polar caps. In some ways, the mysterious planet seemed tantalizingly like Earth. A Martian day is only 37 minutes longer than one on Earth.