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
Solar 2 with asteroids, planets, stars and solar systems. Life forms are also present in the game. They appear on planets sufficiently big to store life, and are represented by a variety of ships of different size and attack power. Spaceships are coloured green if they belong to the player's planet, or to a planet that belongs to the player's solar system; red if they belong to an enemy planet or solar system; and white if they don't belong to any planet or system. All the spaceships in the map are controlled by the game's artificial intelligence (AI), and they will constantly