The atmosphere terraformer can increase and decrease the atmosphere pressure on an entire planet planet by using connected Biome changing remote. This allows for changing previously uninhabitable planets to habitable ones, and allows customizing things like star visibility and crater generation on a per-planet basis. The Terraformer is quite an expensive machine, requiring a very large amount of titanium to get off the ground, through many advanced machine structures. It also requires copious amounts of power and gasses to run.
The Terraformer requires 40 mb/t of nitrogen and oxygen and 1000RF/t for the duration of the terraforming process and takes about an 15 minutes (configurable) to raise/lower the atmosphere by 0.01%. Each 0.01% increase/decrease in atmosphere requires 720 buckets of Oxygen and Nitrogen as well as 18 Million RF.
Once the atmosphere on a planet reaches a critical point (0.25atm, 0.75atm, 2.00atm) the planet's biomes will be modified to reflect the change. Chunks that have not been loaded will appear to have been generated with the new biomes, chunks that have already been loaded will slowly change to the new biome set.