Currently, we only have a vauge form of planetary terraforming based on changing planetary atmospheres. However, some planets are impossible to make completely habitable because, although otherwise perfect, they are too far from a star to be made warm enough to support life without getting too much atmospheric pressure, or else too close.
These new terraforming options would be massive constructions:
- Star Shade: Built by the planet's industrial capacity, these shades would decrease received solar energy by a percentage. Researching this technology further would decrease the cost of building additional shades. In practice, you would enter the desired amount of solar shading on the terraforming screen, and the percentage of production capacity to devote to that; at which point, depending on the tech you have, the amount of stellar energy blocked would gradually increase. Note that attacking a planet stands of chance of damaging any shades it might have, and of course every production cycle there's a chance that natural damage is discovered that would need to be repaired. Keeping a small amount of PC assigned to the solar shades would be ideal.
-Echelon Mirror: Very much like the Star Shade, this mirror system would increase the energy received by a planet. In both cases, not only would research increase the speed of construction, but also the maximum percentage of starlight blocked/increased, and the resilience of existing star shades/mirrors.
Other constructions (such as anti-gravity systems for high-G planets) are already adequately simulated by Infrastructure. These two structures, however, stand the potential of acting as hypothetical colony weapons- like atmospheric terraforming, it can be done to unwilling planets.
Hydroforming:
Currently, it seems that there's no way to change the prevalence of the hydrosphere on a planet. This would basically be the same as an additional "gas" being added to the atmosphere, even if it takes the form of ice or liquid water.
It presumably would not effect atmospheric pressure.
Hypothetically, if you're decreasing the amount of water on a planet significantly, that would represent a great deal of dissolved gold, uranium, ect... that would get collected. Perhaps there would be a small economic bonus for planets that are currently draining the oceans? Perhaps not.
