Luna

The sole natural satelite of Earth, renamed from a 'Moon' when Mankind colonized numerous other moons within the Solar System. It ended up being terraformed with the use of the wondrous nanotechnology of the Sidhe, though mostly due to its proximity to Earth and the fact that it was already housing a substantial population before the Blackout.
Today, Luna remains an equal of any of the signatory states of Earth. Most of the extraterrestrial colonies consider Luna to be an extension of Earth, an additional continent located a bit further from the others than the rest of those.

Geography

Luna isn't an oceanic world, but it has a rather expansive hydrosphere composed of two large and mostly connected oceans and numerous endorheic water basins with no connection to the ocean, typically depending on the rainfall to sustain themselves (although this has been changed by human engineering - expect many manmade canals made to control the water level of such places).
The low gravity means high waves, especially on the side facing Earth. As a result of that, coastlines are usually reinforced by extremely tall walls supposed to break them before they would flood the continents of Luna. There is a single landmass, and a number of smaller islands, typically wrecked by tidal waves on an almost daily basis. It's also a rather rainy place, as the air currents make a light rain fall almost every night, almost everywhere. This is at least partially caused by large temperature amplitude between the day and night.

Fauna & Flora

Luna is suffering from the same problem as all terraformed worlds of the Solar System - the fact that soil can't be rendered fertile as quickly as the atmosphere can be made breathable. As a result, most of its plantlife is limited to the standard set of fungi, lichen, algae and moss.
This, naturally, limits the selection of animals that can thrive on this planet to rodents and other small herbivores. There are plans of introducing many other animals, though for now most of them are in the planning stage.

History

Luna was the place of the first permanent human habitat outside of Earth. It was also the field of the first extraterrestrial ground warfare of Earth, as it become a battleground during the Third World War. Just like the Venus, it was initially colonized by the Union of Progress and Freedom, though soon enough the Alliance for the Preservation of Democracy have also created their own colonies on Luna, only to be driven out from it during the Third World War.
This, however, didn't last, as the UPF lost the war on Earth and subsequently collapsed. Luna become the place of the last stand of the UPF forces, finally dislodged in 2090 during the short Lunar War. The moon remained in the Alliance sphere of influence until the Fourth World War, during which the remaining Union loyalists staged a brief civil war that they ended up losing. After the war ended, Luna turned independent, although not before driving the rebels off-world.
It has continued existing as the United Lunar Republic ever since, becoming a notable power of the Solar System, especially due to housing a significant part of Earth pre-Blackout shipyards, taking advantage of its low gravity to easily lift materials processed on the surface back onto its orbit - or to just construct smaller starships on its surface and launch them from there. That's what allowed Luna to lobby for an access to the terraformation nanotechnology in order to make their world significantly more habitable.
Today, its situation is rather complicated. On one hand, it's still remaining as the centre of starship construction for the Earth Subsystem and houses a rather vibrant economy that's required to support it - and it can also largely feed itself, even if food imported from Earth is still much better and only a bit more expensive. However, while it's cooperating with the nations of Earth, there are still some grievances between the two sides, especially considering Luna siding with the other colonies in order to bid for independence after the Fourth World War.

Luna
Summary
Distance from Sun: 149.5 mil. km
Distance from Earth: 0.38 mil. km
Diameter: 3484 km
Solar Constant: 1.98
Mass: 0.0123 Earths
Gravity: 0.166g
Mean density: 3.44 kg/l
Orbital period: 27.322 days
Day Length: 29.53 days
Rotation Axial Tilt: Similar to Earth

Avg. Temperature per Latitude
poles: -22 C
75 deg: -2 C
60 deg: 6 C
45 deg: 12 C
30 deg: 18 C
15 deg: 22 C
equator: 27 C

Astrography

Object Type: Terrestrial Moon
Object Subtype: Terran Eccentric
Primary Location: Core Sector
Secondary Location: Solar System
Tertiary Location: Earth Subsystem
Transshipment Station: Hephaestus Station

Habitation Status

Status: Colonized
Classification: Civilized World
Population: ~98 mln.
Capital: Horizon City
Government: United Lunar Republic
Solar Commonwealth Member: Yes.