Three rock fragments retrieved from the moon by an unmanned Soviet space mission in 1970 were sold for $855,000 at a New York auction on November 29.
Sotheby's auction house said the moon rocks are the only documented lunar material in private hands. They were offered for sale by an unidentified private American collector who purchased them at auction in 1993 for $442,500.
Sotheby's said the latest buyer was another private American collector, but did not disclose the name.
The lunar samples originally belonged to Nina Korolyova, the widow of former Soviet space program director Sergei Korolyov. They were presented to her as a gift by the Soviet government in recognition of her husband’s contributions to the program, Sotheby's said.
Korolyov was a rocket engineer, aircraft and spacecraft designer, and mastermind behind the Soviet space program during the 1950s and 1960s.
The fragments were retrieved in September 1970 by the unmanned Luna-16 mission, which drilled a hole in the moon's surface to a depth of 35 centimeters and extracted a core sample, the auction house said.
Most other known samples taken from the moon remain with the two governments that collected them: the United States during the Apollo missions and the Soviet Union -- now Russia -- via the unmanned Luna missions.
Collectors pay large sums for space artifacts. Last year Sotheby's fetched $1.8 million for a zippered bag used by U.S. astronaut Neil Armstrong to bring back rock samples taken during the first manned mission to the moon in 1969.
"Space exploration is something that's universal," Sotheby's expert Cassandra Hatton told AFP.
"Anybody can look up at the sky and get excited about it. So we have a lot of interest from around the world."