Colonization of the inner Solar System Colonization of the inner Solar System Bodies in the inner Solar System have been considered for terraforming and space colonization. The main candidates for colonization in the inner Solar System are Mars and Venus. Other possible candidates for colonization include the Moon and even Mercury. The short distance between the Earth and the Moon makes it a natural expansion after Earth. A number of government space agencies have periodically floated lunar plans such as Russia (2014), China (2012) and the US have made plans in constructing the first lunar outpost. The European Space Agency (ESA) head Jan Woerner has proposed
Moons of Jupiter closer to Jupiter; these serve as sources of the dust that makes up Jupiter's rings. The remainder of Jupiter's moons are irregular satellites whose prograde and retrograde orbits are much farther from Jupiter and have high inclinations and eccentricities. These moons were probably captured by Jupiter from solar orbits. Twenty-seven of the irregular satellites have not yet been officially named. The physical and orbital characteristics of the moons vary widely. The four Galileans are all over in diameter; the largest Galilean, Ganymede, is the ninth largest object in the Solar System, after the Sun and seven of the planets, Ganymede