Terraforming is the process of reshaping or otherwise modifying the ecology of a planet or moon to make it more habitable for life that depends on an environment much like Earth. As other cultures came into contact with Humans, they may have adopted the word into their language, or the universal translator may simply have translated their equivalent word into English. Hence, in its broadest sense, terraforming came to mean transforming the ecology of a planetary body such that those performing the procedure could live safely on the surface.
Its converse is bioforming.
- Blue Horizon (DS9: "Second Sight")
- Browder IV - a project that was assisted by the starships USS Hood and USS Enterprise-D in 2366 (TNG: "Allegiance")
- Caldos colony - established in the 22nd century (TNG: "Sub Rosa")
- Doraf I - in 2368, the Enterprise-D was scheduled to undertake a terraforming mission here (TNG: "Unification I")
- Epsilon 119 - a dead star was reignited with protomatter in the first phase of creating a new star system (DS9: "Second Sight")
- Genesis Planet - created in 2285 from the Mutara Nebula, but destroyed as a result of the Genesis Device, which contained protomatter (Star Trek II: The Wrath of Khan; Star Trek III: The Search for Spock)
- Mars - as of 2155, conditions on Mars were sufficiently altered to allow Humans to survive on the surface by only having to use small breathing gear and thermal insulation (ENT: "Demons")
- Moab IV - site of the Genome colony (TNG: "The Masterpiece Society")
- New Halana (DS9: "Second Sight")
- Regula - a Class D planetoid whose interior was terraformed as the second phase of Project Genesis (Star Trek II: The Wrath of Khan)
- Velara III - site of the Velara Base; mission abandoned in 2364 after life was discovered on the planet (TNG: "Home Soil")
- Venus - site of several terraforming stations by the 24th century (DS9: "Past Tense, Part I")
- Weytahn - a Class D planetoid terraformed by the Andorians for habitation in the 2050s (ENT: "Cease Fire")