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.

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.

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.