One lucky bidder will soon fork over millions of dollars to take home NWA 16788, a 54-pound (24-kilogram) Martian meteorite. This space rock, discovered in the Sahara Desert in 2023, is the largest chunk of the Red Planet ever found on Earth.
Sotheby’s, a New York-based auction house, estimates the meteorite could fetch up to $4 million during its natural history sale on Wednesday, July 16. Bidding starts at a cool $1.9 million. Sotheby’s describes NWA 16788 as an “incredibly rare discovery” that traveled 140 million miles (225 million kilometers) through space before plunging into Earth’s atmosphere and crash-landing in the desert. Based on its composition, scientists believe a powerful asteroid impact dislodged this meteorite from the surface of Mars.
“NWA 16788 is a discovery of extraordinary significance—the largest Martian meteorite ever found on Earth, and the most valuable of its kind ever offered at auction,” Cassandra Hatton, vice chairman for science and natural history at Sotheby’s, said in a statement. “This remarkable meteorite provides a tangible connection to the red planet—our celestial neighbor that has long captured the human imagination.”
The reddish-brown boulder is roughly 70% bigger than the next-largest piece of Mars found on Earth, which makes it a singular find among an incredibly rare class of geologic specimens. According to Sotheby’s, only 400 of the more than 77,000 officially recognized meteorites come from Mars. The auction house estimates that this single rock represents roughly 6.5% of the total mass of all known Martian material on Earth.
A meteorite hunter discovered NWA 16788 exactly two years before its auction date while searching for space rocks in the Kefkaf region of Niger, according to The Meteorological Society. The organization documented its physical characteristics as a “grey to brown exterior surface partially covered with a grey to brownish fusion crust.”
A fusion crust is a key feature that distinguishes meteorites from Earth rocks. This dark, glossy exterior forms when the meteorite plummets through our planet’s atmosphere at incredibly high speeds. The force of its descent compresses and heats the air in its path, causing its exterior to melt and ablate. When the meteorite slows down enough to stop melting, the last melt cools to create a glassy coating. According to Sotheby’s, NWA 16788’s surface also bears regmaglypts—shallow depressions probably created by small vortices of hot gas carrying droplets of molten meteorite that erode parts of the surface as the space rock falls to Earth.
Aside from these markings, NWA 16788 shows minimal signs of terrestrial weathering, indicating that it probably arrived on our planet relatively recently, Sotheby’s explains. Following its discovery, The Shanghai Astronomy Museum received a small piece of the meteorite for identification, classifying it as a shergottite, the most abundant type of Martian meteorite found on Earth. These igneous rocks form from volcanic activity on Mars, solidifying from molten magma.
It may seem unusual to put this remarkable specimen up for sale rather than displaying it in a museum. Before it arrived at Sotheby’s, the Italian Space Agency in Rome and a private gallery in Arezzo publicly exhibited NWA 16788, Tuscany, according to Sotheby’s. Some experts aren’t thrilled to see it stashed away in someone’s personal collection.
“It would be a shame if it disappeared into the vault of an oligarch. It belongs in a museum, where it can be studied, and where it can be enjoyed by children and families and the public at large,” Steve Brusatte, a professor of paleontology and evolution at Scotland’s University of Edinburgh, told CNN. Julia Cartwright, a planetary scientist and independent research fellow at the University of Leicester, England, sees things differently. “Ultimately, if there was no market for searching, collecting and selling meteorites, we would not have anywhere near as many in our collections—and this drives the science!” she told CNN.
No matter where it ends up, NWA 16788 will always serve as a reminder of the strange and extraordinary ways Earth interacts with other planets in the solar system. Human exploration of Mars may still be a long way off, but once in a while, the cosmos brings a piece of the Red Planet to us, helping scientists unravel the mysteries of our celestial neighbor.
