A 30-pound piece of the moon is up for sale

The lunar meteorite, known as NWA 12691, fell to Earth in a meteor shower and was found two years ago in the Sahara Desert, according to a news release from Christie's.

The asking price is in the neighborhood of $2.5 million, Christie's said. It's a private sale instead of an auction, so anyone with the money can buy it immediately.

The moon rock weighs in at just under 30 pounds (13.5 kilograms) and is the fifth-largest piece of the moon on Earth, the statement said.

"There aren't even a handful of larger lunar meteorites: this is the fifth largest known. Nothing brought back by the Apollo Missions is as large," James Hyslop, Christie's Head of Science & Natural History told CNN via email. "It is really an incredible opportunity to acquire a world class specimen from the Moon."

The rock was probably knocked off the moon's surface by a collision with an asteroid or a comet, Christie's said.It then had to travel at least 239,000 miles through space before falling to Earth in a fiery meteor shower. About 30 meteorites from that shower have been found in Northwest Africa, the statement said.

Lunar meteorites are very rare and Christie's said that only 1,443 pounds of them (650 kilograms) are known to exist on Earth.

"It is an order of magnitude larger than any other lunar meteorite we've sold," Hyslop said. "All previous examples would have been able to fit in your hand, but this is over 10 times larger."

Apollo 16 astronauts brought home a specimen nicknamed "Big Muley" in 1972 that weighed almost 26 pounds (11.7 kilograms).