The largest piece of Mars ever found on Earth was sold for just over $5m at an auction of rare geological and archaeological objects in New York on Wednesday, while a juvenile dinosaur skeleton went for more than $30m.
The 54-pound (25kg) rock named NWA 16788 was discovered in the Sahara desert in Niger by a meteorite hunter in November 2023, after having been blown off the surface of Mars by a massive asteroid strike and traveling 140m miles (225m km) to Earth, according to Sotheby’s. The estimated sale price before the auction was $2m to $4m.
The identity of the buyer was not immediately disclosed. The final bid was $4.3m. Adding various fees and costs, the official bid price was about $5.3m.
Two advance bids of $1.9m and $2m were submitted. The live bidding went slower than for many other objects that were sold, with the auctioneer trying to coax more offers and decreasing the $200,000 to $300,000 bid intervals to $100,000 after the proposals hit $4m.
The red, brown and gray meteorite 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 15in by 11in by 6in (375mm by 279mm by 152mm).
It was also a rare find. There are only 400 Martian meteorites out of the more than 77,000 officially recognized meteorites found on Earth, the auction house says.
“This Martian meteorite is the largest piece of Mars we have ever found by a long shot,” Cassandra Hatton, vice-chairman for science and natural history at Sotheby’s, said in an interview before the auction. “So it’s more than double the size of what we previously thought was the largest piece of Mars.”
It is not clear exactly when the meteorite was blasted off the surface of Mars, but testing showed it probably happened in recent years, Sotheby’s says.
Hatton said a specialized lab examined a small piece of the red planet remnant and confirmed it was from Mars. It was compared with the distinct chemical composition of Martian meteorites discovered during the Viking spacecraft that landed on Mars in 1976, she said.
The examination found that it was an “olivine-microgabbroic shergottite”, a type of Martian rock formed from the slow cooling of Martian magma. It has a coarse-grained texture and contains the minerals pyroxene and olivine, Sotheby’s says.
It also has a glassy surface, probably due to the high heat that burned it when it fell through Earth’s atmosphere, Hatton said. “So that was their first clue that this wasn’t just some big rock on the ground,” she said.
The meteorite previously was on display at the Italian Space Agency in Rome. Sotheby’s did not disclose the owner.
Bidding for the juvenile Ceratosaurus nasicornis dinosaur skeleton started with a high advance bid of $6m, then escalated with offers $500,000 higher than the last and later $1m higher than the last before ending at $26m. The official sale price was $30.5m with fees and costs. The original estimate was $4m to $6m.
Parts of the skeleton were found in 1996 near Laramie, Wyoming, at Bone Cabin Quarry, a goldmine for dinosaur bones. It is more than 6ft (2 meters) tall and nearly 11ft long.
Specialists assembled nearly 140 fossil bones with some sculpted materials to recreate the skeleton and mounted it so it is ready to exhibit, Sotheby’s says.
The skeleton is believed to be from the late Jurassic period, about 150m years ago, Sotheby’s says.
Ceratosaurus dinosaurs were bipeds with short arms that appear similar to the Tyrannosaurus rex, but smaller. Ceratosaurus dinosaurs could grow up to 25ft long, while the Tyrannosaurs rex could be 40ft long.
The skeleton was acquired last year by Fossilogic, a Utah-based fossil preparation and mounting company.
Wednesday’s auction was part of Sotheby’s Geek Week 2025 and featured 122 items, including other meteorites, fossils and gem-quality minerals.