Abstract
The Inner Solar System hosts several valuable planet-sized objects, that should be
targeted by human colonization.
The Moon has the major advantage of being close to Earth, plus also having several
useful features, such as low gravity (perfect for space launch) and useful mineral
resources. It hosts vast areas suitable for enclosed settlements of limited terraformation.
However, there are clues that, in time, it could be fully terraformed.
Mercury is a small, hot and dry planet, a tough target for future colonists. Planetary
engineering could also work in these conditions, eventually allowing terraforming, or at
least large-scale paraterraformation, under a planetary "shell”.
Finally, in the Main Asteroid belt, Ceres could be the easiest terraformable object in the
whole System. There are also technical solutions that could turn other planetoids and
small moons into new homeworlds for humankind.