There are plenty of lunar samples on Earth. These are only ones known to be in private hands. Returned to Earth by the unmanned Soviet Luna-16 mission, these moon rocks were presented to the widow of the Soviet space program’s director. They have remained in the same private collection since being initially sold in 1993 for nearly $450,000. They’re encased under glass below an adjustable lens and labeled “ЧАСТИЦЫ ГРУНТА ЛУНЫ-16” [SOIL PARTICLES FROM LUNA-16] on a plate below. The samples will be offered as part of a larger Space Exploration auction, taking place at Sotheby’s in New York on November 29.