Luna is a small planet located in the orbit of the planet Earth of which it lies as one of the two moons of the Earth.
Luna was at the time of the arrival of the Old Ones devoid of an atmosphere but this changed as while the Old Ones worked on turning Earth into their version of utopia it was Luna that became the site of their work stations and watching posts. For the ease of their operations the Old Ones terraformed Luna adding atmosphere and oceans and also moved Luna's orbit slightly further away from the Earth itself and it was this condition that Luna would remain ever following the departure of the Old Ones.