Estimated auction price: $2 million to $4 million. Why so expensive? It's the largest piece of Mars ever found on Earth. Sotheby's in New York will be auctioning what's known as NWA 16788 on Wednesday ...

NWA 16788 is the largest martian meteorite ever found, weighing in at 54 pounds. Soon, it’ll be up for auction.

On Wednesday, Sotheby’s will auction off a chunk of rock believed to have originated on Mars for an anticipated two to four ...

Out of the 122 lots, the main event is NWA 16788, a Martian meteorite that is the largest piece of Mars ever found on Earth.