If rocks could talk, this one (NWA 16788) would have a great tale to tell. It was ejected from its own planet by a massive asteroid collision, wandered around in space for ages, then eventually found its way into the gravitational field of Earth and landed 140 million miles from where it started, being found in 2023.
NWA16788 is the largest known piece of Mars on Earth, and its internal composition suggests it was disgorged from the surface of the Red Planet by an asteroid impact so extreme that it turned some of the meteorite’s minerals into glass.
Looking certain to blow past its lower estimate of US$2 million, this monumental 54-lb (24.67-kg) lump of Mars has already been bid to $1,920,000 (inc Buyer’s Premium) 12 days before the on-line hammer falls, and even its $4-milllion upper estimate doesn’t look safe with this much interest so early in an online auction.
The reason for this rock's hyper-expensive price is rarity: of the more than 77,000 officially recognized meteorites, only 400 are Martian meteorites, and this is by far the biggest ever found.
Those familiar with the nomenclature of meteorites will already be aware from the NWA prefix that it was found in North West Africa, but to be more specific, it was found in Niger’s remote Agadez region of the Sahara desert by a professional meteorite hunter.
The largest known piece of Mars on Earth will sell on 16 July 2025 during Sotheby’s annual marquee science series of auctions known as Geek Week.
Update (July 17, 2025): As predicted, NWA 16788 went for more than its $2 million to $4 million estimate, the hammer dropping on a final bid of $4.3 million. Add on the various fees and costs and the official bid price was $5.3 million.
