A meteorite that is the largest known piece of Mars on Earth is expected to fetch up to $4 million when it goes up for auction at Sotheby’s on July 16.

Bias on the basis of color has gnawed at me all my life because it does not make any sense and cannot be reconciled, Will Arvelo writes.

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