Terraformers are used to adjust planet temperature, atmosphere, weather and gravity to ideal levels. They are generally inefficient on their own and often take quite a long time to function.

Each terraformer on a world raises the chance of the planet improving over time. The more there are on a planet, the higher the chance.

The worse a planet's conditions, the quicker it will change. The better the planet's habitability the smaller the chance. So your terraformers may work for a while, but as the planet improves, further changes become less likely.

Once a planet has been terraformed, terraformers are no longer necessary and can be demolished to recover some resources.

See Also: Terraforming