Among items going up for auction at Sotheby's in New York is a 54-pound rock that the auction house calls the largest piece ...

The largest fragment of Mars ever discovered on Earth, a 54-pound meteorite named NWA 16788, is set for auction at Sotheby's in New York.

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