A chunk of the Martian surface that made unlikely voyage to Earth will be available to highest bidder at Sotheby's auction in New York July 16, 2025.

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.

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 later this month.