possible Mars meteorites have no pristine samples to be compared with. During the Apollo years, astronauts physically brought hundreds of pounds of moon rocks back to Earth, and those samples still serve as the isotopic reference point for determining ...

A chunk of the Martian surface that made an unlikely voyage to Earth will be available to the highest bidder at Sotheby's auction in New York.

The red, brown and gray hunk is about 70% larger than the next largest piece of Mars found on Earth and represents nearly 7% of all the Martian material currently on this planet, Sotheby’s says. It measures nearly 15 inches by 11 inches by 6 inches.