For sale: a 25-kilogram rock. The expected price is between $2 million and $4 million. This is the largest piece of Mars ever found on Earth.

Sotheby's auction house in New York will offer this unique meteorite, known as NWA 16788, at auction on Wednesday as part of a themed sale dedicated to natural history. Other items on offer include the skeleton of a young ceratosaurus, a dinosaur over 2 meters tall and almost 3 meters long.

According to Sotheby's, the meteorite was ejected from the surface of Mars after a massive collision with an asteroid and traveled 225 million kilometers before falling in the Sahara. There it was discovered by a meteorite hunter in Niger in November 2023.

The piece, with red, brown, and gray hues, is about 70% larger than the second-largest Martian meteorite found on Earth and represents nearly 7% of all Martian material known on our planet. Its dimensions are approximately 38 x 28 x 15 cm.

"This is the largest piece of Mars we have ever found — by a huge margin," said Cassandra Hatton, vice president of scientific and natural history objects at Sotheby's.

The meteorite is extremely rare. Of the more than 77,000 officially recognized meteorites on Earth, only about 400 are of Martian origin.

A small part of the find was sent to a specialized laboratory, which confirmed this. The sample was compared to the characteristic chemical composition of meteorites analyzed during NASA's Viking mission in 1976. | BGNES