Colonization of the outer Solar System Colonization of the outer Solar System Many parts of the outer Solar System have been considered for possible future colonization. Most of the larger moons of the outer planets contain water ice, liquid water, and organic compounds that might be useful for sustaining human life. Colonies in the outer Solar System could also serve as centers for long-term investigation of the planet and the other moons. In particular, robotic devices could be controlled by humans without the very long time delays incurred in communicating with Earth. There have also been proposals to place robotic aerostats in the upper atmospheres of
Minor planet asteroids. A minor planet seen releasing gas may be dually classified as a comet. Objects are called dwarf planets if their self-gravity is sufficient to achieve hydrostatic equilibrium and form an ellipsoidal shape. All other minor planets and comets are called "small Solar System bodies". The IAU stated that the term "minor planet" may still be used, but the term "small Solar System body" will be preferred. However, for purposes of numbering and naming, the traditional distinction between minor planet and comet is still used. Hundreds of thousands of minor planets have been discovered within the Solar System and thousands