Terraforming

Template:Generic The principle of Terraforming in Aurora is based on changing the atmosphere in order to alter the environment of the planet so it is suitable for your species.

The actual mechanics of using terraforming in the game interface are relatively straightforward. If you have any terraforming installations on a planet or any ships with terraforming modules in orbit, go to the Environment tab, select the gas you want and type the target amount of gas for the terraformers to meet. Make sure to check the Add Gas checkbox if you're adding gas (or uncheck it if you're removing it).

Terraforming installations are ground-based and require workers. Terraforming modules are installed on ships in space, and do not require any workers, but do require the overhead of building a ship instead. Spaceborne and ground-based terraforming installations are boosted by the Terraforming skill of the ship captain and governor, respectively.

There are a wide range of gases you can add or remove from an atmosphere, with some being safe (no impact on colony cost) and others being dangerous (colony cost 2-3 minimum if they're in the air at all (VB6) or beyond the safe concentration of that gas (C#)).

Increasing a planet's atmosphere will warm it somewhat, and some gases are greenhouse gases that warm it much more aggressively.

Surface Temperature in Kelvin = Base Temperature in Kelvin x Greenhouse Factor x Albedo
Greenhouse Factor = 1 + (Atmospheric Pressure / 10) + Greenhouse Pressure (Maximum = 3.0)

There is also an anti-greenhouse gas, which can lower a planet's temperature significantly. Mechanics for this differ between versions - see the version pages for details.

The gas your race breathes (oxygen, by default) has some special mechanics. You must have an absolute pressure of that gas within a given range (0.1-0.3 atm, by default), and it must not have a relative pressure above 30%, since atmospheres with too much oxygen can be extreme fire risks. This means that the minimum atmosphere required for safety is 0.334 atm, so you can have 0.1 atm of oxygen, along with 0.234 atm of other gases to keep the relative oxygen pressure down (since 0.1/0.334 = 29.94%, which is below the 30% safety level).

C# additionally contains mechanics related to gases freezing out of the atmosphere, water liquifying into oceans, and terraforming difficulty scaling with body size. See the C-Terraforming article for details.