Paraterraforming

Paraterraforming (or World House Design) is a subset of Terraforming where it takes place inside huge structures which may cover a large fraction of a world's surface. A key advantage is that the economic benefits of terraforming can be enjoyed much more quickly.

Introduction:

Many people are concerned about long term Atmospheric loss on Mars, and by building huge structures this can be completely avoided. A large crater (say 10 km across), could have a 'tent pole' placed in the centre of it, and then a transparent material could drape from the tent pole to the crater rim. Under this tent, atmospheric pressure could be increased, and it could be given a breathable atmosphere. Over time, more and more larger craters can be so engineered, until a significant fraction of the world is habitable. At this time, you could say that Mars has been Paraterraformed.

Asteroids are far too small to have an atmosphere, but are close enough to Sol to allow the growing of crops. Let us say that we surrounded Ceres with a rigid, self-sealing, transparent dome. Everywhere the 'glass sky' would be a couple km above the surface. Under this planet-covering dome, a thick atmosphere can exist.