mars photos

Many people -- from scientists to sci-fi writers -- have ruminated on the possibility that Earth was long ago discovered by another society. After all, the planet's been sitting around for more than four billion years. If anyone has ever visited our world, it's possible they left a calling card.
"The black object looks like a crashed UFO."
The dark veins? They're a bit of a mystery. "Some of them look like ice-cream sandwiches: dark on both edges and white in
A weird circular landform recently spotted on the surface of Mars might look like a deformed waffle--or maybe the surface
Of course, that hasn't stopped folks from trolling through photos taken by NASA rovers and probes -- spotting objects that