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.
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.