7 days ago
Why this rare Martian rock could fetch up to $9 million at auction
At first glance, it might seem like an ordinary hunk of stone, but this particular rock is poised to fetch upwards of AU$6 million at an upcoming auction.
Why would someone invest millions in a rock? Well, this cosmic treasure is far more interesting than it looks.
Like some men, this rock is from Mars (crashing Earth's party uninvited is so on brand) and is the largest piece of the red planet ever found on Earth.
Sotheby's in New York is set to auction this 25-kilogram Martian Meteorite on 16 July, as part of its natural history-themed sale. The estimated price ranges from $2 million to $4 million USD, equivalent to AU$6 million to AU$9 million.
This event is a highlight of Sotheby's 'Geek Week' 2025 series, showcasing 122 fascinating items, including fossils, meteorites, and gem-quality minerals.
Officially known as Northwest Africa 16788 (NWA 16788), it's believed to have been ejected from Mars by a colossal asteroid impact.
According to Sotheby's, it travelled approximately 225 million kilometres through the cosmos, landed on Earth, and was eventually discovered in the Sahara Desert.
A meteorite hunter found the blackened rock in Niger in November 2023. Sotheby's says it's about 70 per cent larger than the next biggest known Martian specimen and represents nearly 7 per cent of all Martian material ever found on Earth.
'This Martian meteorite is the largest piece of Mars we have ever found by a long shot,' said Cassandra Hatton, vice chairman for science and natural history at Sotheby's.
'So it's more than double the size of what we previously thought was the largest piece of Mars.'
The meteorite measures nearly 37.5 centimetres by 27.9 centimetres by 15.2 centimetres and weighs 24.67 kilograms. Its glassy outer layer formed from the extreme heat it experienced while falling through Earth's atmosphere.
A small sample was sent to a specialised lab for analysis, which confirmed its Martian origin. Scientists matched its unique chemical composition with rocks analysed by NASA's Viking landers, which touched down on Mars in 1976.
'That was their first clue that this wasn't just some big rock on the ground,' Hatton told the Associated Press.
Sotheby's classifies the meteorite as a type of volcanic rock formed from the slow cooling of Martian magma. The specimen has a rough texture and contains the common rock-forming minerals pyroxene and olivine.
With only about 400 known Martian meteorites among over 77,000 officially recognised meteorites on Earth, this find is exceptionally rare.
'It really is quite an impressive specimen,' Hatton said.
Background information released by Sotheby's notes that the meteorite was previously exhibited at the Italian Space Agency in Rome. However, the auction house has not disclosed its current owner.
The exact timing of the meteorite's arrival on Earth remains uncertain, though tests suggest it likely fell in recent years.
Sotheby's notes that collectors often share such specimens with museums or lend them to institutions, but some scientists worry that private sales might limit research access to these rare planetary materials.
The auction will also feature a nearly complete juvenile Ceratosaurus skeleton, discovered in Wyoming in 1996. This dinosaur, standing almost two metres tall and over three metres long, is also expected to sell for $6 million to $9 million.
