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
Extraterrestrial liquid water to conclusive confirmation of deposition by liquid water. On December 9, 2013, NASA reported that the planet Mars had a large freshwater lake (which could have been a hospitable environment for microbial life) based on evidence from the Curiosity rover studying Aeolis Palus near Mount Sharp in Gale Crater. Comets contain large proportions of water ice, but are generally thought to be completely frozen due to their small size and large distance from the Sun. However, studies on dust collected from comet Wild-2 show evidence for liquid water inside the comet at some point in the past. It is yet