Moon

Article By:

Burke, James D. Formerly, Spacecraft Systems Engineering, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.

Last reviewed:August 2022

DOI:https://doi.org/10.1036/1097-8542.434600

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• Moon, published February 2019:Download PDF Get Adobe Acrobat Reader
• Moon, published June 2014:Download PDF Get Adobe Acrobat Reader

The Earth's natural satellite. The Moon is a solid body orbiting our planet and is by far the brightest object in the night sky (Fig. 1). Many nations including the United States, China, members of the European Space Agency, India, Japan and Russia have all sent spacecraft that have orbited or landed on the Moon. The Apollo missions undertaken by the American government in the late 1960s and early 1970s represent the only times that humans have visited the Moon. The Apollo crews landed, walked, and roved upon the lunar surface. The crews brought back a total of 382 kg (842 lb) of Moon rocks for study on Earth, the vast bulk of lunar material retrieved so far. After a long hiatus, significant interest has resumed in humans returning to and perhaps eventually residing upon the Moon. See also: Astronautics; Space probe

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