The colonization of the Moon is the proposed establishment of permanent human communities on the Moon. Advocates of space exploration have seen settlement of the Moon as a logical step in the expansion of humanity beyond the Earth. Recent indication that water might be present in noteworthy quantities at the Lunar poles has increased interest in the Moon. Polar colonies could also avoid the problem of long Lunar nights (about 354 hours, a little more than two weeks) and take advantage of the sun continuously.
Permanent human habitation on a planetary body other than the Earth is one of science fiction's most prevalent themes. As technology has advanced, and concerns about the future of humanity on Earth have increased, the argument that space colonization is an achievable and worthwhile goal has gained momentum. Because of its proximity to Earth, the Moon has been seen as a prime candidate for the location of humanity's first permanently occupied extraterrestrial base.
A lunar outpost was an element of the George W. Bush era Vision for Space Exploration, which has been replaced with President Barack Obama's space policy. The outpost would have been an inhabited facility on the surface of the Moon. At the time it was proposed, NASA was to construct the outpost over the five years between 2019 and 2024. The United States Congress directed that the U.S. portion, "shall be designated the Neil A. Armstrong Lunar Outpost".
On December 4, 2006, NASA announced the conclusion of its Global Exploration Strategy and Lunar Architecture Study. The Lunar Architecture Study's purpose was to "define a series of lunar missions constituting NASA's Lunar campaign to fulfill the Lunar Exploration elements" of the Vision for Space Exploration. What resulted was a basic plan for a lunar outpost near one of the poles of the Moon, which would permanently house astronauts in six-month shifts. These studies were made before the discovery of water ice (5.6 ± 2.9% by mass) in a polar crater, which may substantially affect plans.