Largest Known Martian Meteorite on Earth Set for Auction in New York

A 54-pound Martian meteorite, described by Sotheby's as the largest piece of Mars ever discovered on Earth, is set to be auctioned in New York on Wednesday. The specimen, known as NWA 16788, is estimated to sell for between $2 million and $4 million as part of a natural history-themed sale that also features a juvenile Ceratosaurus dinosaur skeleton.

According to Sotheby's, the meteorite is believed to have been ejected from Mars by an asteroid impact, traveling approximately 140 million miles before landing in the Sahara Desert. It was discovered in Niger by a meteorite hunter in November 2023. The rock measures nearly 15 inches by 11 inches by 6 inches and is about 70% larger than the next largest known Martian meteorite, representing nearly 7% of all Martian material found on Earth.

Cassandra Hatton, vice chairman for science and natural history at Sotheby's, stated, > "This Martian meteorite is the largest piece of Mars we have ever found by a long shot. So it’s more than double the size of what we previously thought was the largest piece of Mars."

The meteorite was confirmed to be of Martian origin after a laboratory analysis matched its chemical composition to samples identified by the Viking space probe in 1976. Sotheby's reports that it is an olivine-microgabbroic shergottite, a rare type of Martian rock formed from slowly cooled magma, and features a glassy surface from its entry through Earth's atmosphere. Only about 400 Martian meteorites are among the more than 77,000 officially recognized meteorites on Earth.

The meteorite was previously exhibited at the Italian Space Agency in Rome, though Sotheby's has not disclosed the current owner. Testing suggests it arrived on Earth in recent years.

Also included in the auction is a juvenile Ceratosaurus nasicornis skeleton, discovered in Wyoming in 1996 and estimated to fetch between $4 million and $6 million. The skeleton, dating to the late Jurassic period, was assembled from nearly 140 fossil bones and additional sculpted materials. The auction is part of Sotheby's Geek Week 2025, featuring 122 items including meteorites, fossils, and minerals.