A rock is expected to fetch up to $4 million in an auction — it's the biggest chunk of Mars on Earth

Deep space requires deep pockets. Sotheby’s annual Natural History Auction includes several out-of-this-world items, including the largest Martian meteorite ever found, a piece of the moon shaped into a sphere, and a space rock that’s being advertised as “the oldest matter than can be seen and touched.”

Lot 69 is a Martian meteorite with the prosaic name NWA 16788 . It was found in 2023 in the Sahara Desert region of Niger. Covered in reddish-brown crust “giving it an unmistakable Martian hue,” the rock was probably blasted out of the surface of the red planet by an asteroid strike, before making the 225-million-kilometre journey to Earth.

The meteorite weighs almost 25 kilograms, making it almost twice as heavy as the next biggest specimen from Mars. There are only about 400 known Martian meteorites on the Earth with a total weight of 374 kilograms, so this one rock represents about 6.5 per cent of all the known Martian material on our planet.

“NWA 16788 shows minimal terrestrial weathering,” the auction house catalogue says, “indicating that its physical and chemical makeup have not been significantly altered since its arrival in the Sahara Desert. In other words, NWA 16788 is likely a relative newcomer here on Earth, having fallen from outer space rather recently.”

This slab of Mars is expected to sell for between $2 million and $4 million (all figures in U.S. dollars) when the auction takes place on July 16. As of Monday, July 7, it already had a pre-auction bid of $1.6-million.

Among the other 122 lots up for sale is the largest known lunar sphere — other than the moon itself, which is about 3,500 kilometres across. This piece of the moon was also found in the Sahara Desert and is thus part of only 1,536 kilograms of confirmed lunar meteorites found to date.

Collectors have previously shaped lunar meteorites into spheres, although the auction catalogue notes that fear of cracking them gives many pause. And while most of the spheres are less than 40 mms in diameter, the one for sale by Sotheby’s is 120 mm across (almost five inches) and weighs a hefty 2.54 kilograms. The rock is expected to fetch between $300,000 and $500,000.

Another meteorite up for sale has a bit of lunar history attached to it. On Feb. 8, 1969, a fireball was seen in the skies over northern Mexico. In the days that followed, pieces of the meteorite were found on the ground and analyzed by scientists from NASA, using equipment that would, a few months later, study samples of the moon brought back by the crew of Apollo 11.

Those scientists discovered that the Allende meteorite (named for where it fell in Mexico) contained what is believed to have been some of the first solid matter to form in the solar system, billions of years ago. As such, it’s become known as “the Rosetta Stone for planetologists.” But for the sake of the auction it’s also described as “the oldest matter than can be seen and touched.” The winning big for this ancient space rock is expected to be a relatively modest sum of $3,000 to $5,000.

The auction, which will take place in New York City on July 16, has a number of other oddities, both from space and Earth. There’s the Sikhote-Alin meteorite, which landed in the Soviet Union in 1947 and comes “adorned with collection stickers and offered with a collection tag from the Soviet Union’s Vernadsky Museum.”

The catalogue also notes that the rock is “made even more special by the fact that it has not been cleaned since it was collected,” surely one of the few times that dirt has been listed as a selling point.

Items of a more terrestrial origin include a neolithic stone axe from Normandy, roughly 6,000 years old, and a “neanderthal tool set” dating from somewhere between 40,000 and 300,000 years ago. There are also a variety of fossils including a mounted juvenile ceratosaurus from the late Jurassic era, about 150 million years ago.

That one is expected to fetch between $4 million and $6 million. A more affordable dino-centric relic is the original LED sign From SEGA’s The Lost World: Jurassic Park arcade game, circa 1997. More than three metres wide and almost two metres tall, it’s likely to go under the hammer for between $20,000 and $30,000.