Like Earth and the solar system's other planets, Mars formed roughly 4.5 billion years ago. Early in its history, Mars was ...

The surface of Mars looks like an empty red wasteland. But if you look a bit closer, the remnants of an ancient alien civilization begin to take shape. At least, that's the conclusion of George J.

Add Yahoo as a preferred source to see more of our stories on Google. The so-called Candor Tetrahedron. (NASA/JPL-Caltech/UArizona) It would be tempting to assume there's nothing much of note ...