Luna

Description
An early source of helium-3, Luna is now mined for materials used in space habitat construction. Two dozen major stations have been constructed at Earth's L4 and L5 Lagrange points, all from lunar resources.

Trivia

 * The presence of the CCCP Luna 23 probe allows the operational zone to be established as the southern portion of Mare Crisium.
 * In the novel Mass Effect: Revelation, it is stated that Luna was "terraformed". It would not be physically possible for Luna to gravitationally retain an Earth-like atmosphere, due to its mass. However, the issue was clarified by the game's developers; several of the moon's craters were "domed over", allowing localized terraforming of the surface.
 * Helium-3 isotope is a potential fuel for future nuclear fusion reactors. Many scientists and science fiction authors have proposed mining the isotope from the planets and moons of the solar system, as a new energy economy, to replace oil and nuclear fission.
 * When looking at Earth from the surface of Luna, a reversed image of North America (Mexico, U.S. West Coast) can be seen.
 * A prevalent in-game wind can be heard, even though Luna's atmosphere is very negligible.
 * Luna is briefly mentioned in Mass Effect 2 when EDI is first introduced if Shepard orders EDI to be shut down due to distrust towards AIs.
 * To hear the rachni song, go to the location on the map, along the ridge near the cliff edge. After a while you'll start hearing a noise that sounds like irregular, guttural whalesong. You may need to stand outside of the mako to hear it, although it can be heard from in the mako once triggered.