Mercury

Mercury is one of the worlds that were terraformed in the aftermath of the Blackout through generous application of terraforming nanites obtained from the Sidhe, turning it into one of the largest bodies in the Solar System with a breathable atmosphere. Following almost four decades of accepting new settlers - and then, immigrants - from Earth, it has become a major population center and a signatory of the Second Treaty of Deimos.
It has a - to some degree justified - reputation of a backwater planet inhabited by weirdoes, hillbillies and fringe religious groups. The fact that it has become an unofficial capital for the Commonwealth's more supernatural endeavours, including a sizeable population of Metaphysicists, Holders and Psychics, only strengthens the image.

Geography

Mercury is a mountain planet, with massive mountains and equally massive depths being its geography's main defining features. The highest mountains approach 10km in height, and while this doesn't seem to be much higher than the highest mountains of Earth, the problem is the sheer number of mountains approaching this limit and how often they can be found right next deep valleys.
While it's not very noticeable for now, the hydrosphere shows signs of moving north and south, away from equator. It is believed that within a century or two large swathes of the planet will began to turn into deserts, at least without human intervention.

Climate

Due to its mountains surface, planet's hydrosphere is formed of many disconnected regions, without oceans but with many rivers, lakes and small inland seas. This leads to harsh weather shifts and storms that often ravage only one particular pocket of valleys surrounded by the giant mountains. This also causes many rivers to enlarge and shrink depending on the rain, with large parts of Mercury being regularly flooded.

Fauna & Flora

In the process of being introduced, though Mercury is still at the stage where biodiversity is almost non-existent and most niches are occupied by a single type of an animal as the planet's inhabitants are busy establishing a basic framework for the ecosystem and its foodchain.
Near the poles, liveforms imported from tundras of Earth thrive relatively well, and the seas are seeded with a new types of fish and other animals every year. The temperate regions are struggling a bit more due to the soil being largely infertile, a fact that's in the process of being remediated by large scale soil-enrichment projects. As a result, thus far most of those regions have their ecosystem limited to lichens, fungi and moss.
In few places, where the soil fertilization process started earliest, first trees can be find.
The equator region has an ecosystem that was mostly imported from arid regions of Earth, which appears to fare pretty well - in a way, better than the temperate region due to weather being somewhat more stable there.

History

Mercury is one of the planets that were rapidly terraformed using the Sidhe nanotechnology in the aftermath of the Blackout, turning it habitable within a decade. It required - and still does - some additional engineering work, in the form of an artificial magnetic shield in the Mercury-Sun L1 point, which allowed Mercury to regain its natural magnetic field, and sunshades that repel some of the excess light and lower the temperature on the surface to managable levels.
Security worries concerning the stability of those installations - and the less than ideal weather conditions on the surface of the planet - led to Mercury not attracting as many settlers as other planets of the Inner System, at least in the early stages of colonization. This made the Commonwealth offer to transport people there pretty cheaply, which in turn led to many fringe groups deciding to take advantage of that in order to be allowed to live under their own rules, away from the Commonwealth's 'boot'.
This over time reduced the planetary government into a mediator between hundreds of local autonomous communities, with its direct control limited to the planetary capital and the surrounding region.

Mercury
Summary

Distance from Sun: 57 mil. km
Diameter: 4879 km
Solar Constant: 13.196
Mass: 0.055 Earths
Gravity: 0.378g
Mean Density: 5.427 kg/l
Orbital Period: 88 Earth days
Day Length: 116 Earth days
Rotation Axial Tilt: <10 degrees

Avg. Temperature per Latitude

Poles: -44 C
75 deg: -10
60 deg: 2 C
45 deg: 12 C
30 deg: 20 C
15 deg: 27 C
equator: 33 C

Astrography

Object Type: Terrestrial Planet
Object Subtype: Terran Eccentric
Primary Location: Core Sector
Secondary Location: Solar System
Tertiary Location: Mercury Subsystem
Satellites: None
Transshipment Station: Icarus Station

Habitation Status

Status: Colonized
Classification: Civilized World
Population: ~102 mln.
Capital: New Geneva
Government: Mercurial Confederation
Solar Commonwealth Member: Yes.