Colonization of the outer Solar System is subject to only 0.01 rem a day. When NASA carried out a study called "HOPE" (Revolutionary Concepts for Human Outer Planet Exploration) regarding the future exploration of the Solar System, the target chosen was Callisto. It might be possible to build a surface base that would produce fuel for further exploration of the Solar System. The Keck Observatory announced in 2006 that the binary Jupiter trojan 617 Patroclus, and possibly many other Jupiter trojans, are likely composed of water ice, with a layer of dust. This suggests that mining water and other volatiles in this region and transporting them
Formation and evolution of the Solar System the Sun's retinue of planets. Some planets will be destroyed, others ejected into interstellar space. Ultimately, over the course of tens of billions of years, it is likely that the Sun will be left with none of the original bodies in orbit around it. Ideas concerning the origin and fate of the world date from the earliest known writings; however, for almost all of that time, there was no attempt to link such theories to the existence of a "Solar System", simply because it was not generally thought that the Solar System, in the sense we now understand it, existed.