NASA has revealed a concept for the next generation of flight on the Red Planet, the "Mars Chopper." Credit: Space.com | ...

Sotheby's is putting some rare items up for auction, including what it calls the largest piece of Mars ever found on Earth.

Mars is easiest to see when it’s closest to Earth, which happens about every two years. This event is called “opposition.” In ...

A 54-pound (25-kilogram) rock with an estimated auction price of $2 million to $4 million. Why so expensive? It’s the largest ...