Colonization of the outer Solar System the Solar System's gas giant planets for exploration and possibly mining of helium-3, which could have a very high value per unit mass as a thermonuclear fuel. The Jovian system in general has particular disadvantages for colonization, including its severe radiation environment and its particularly deep gravity well. Its radiation would deliver about 3,600 rems per day to unshielded colonists on Io and about 540 rems per day to unshielded colonists on Europa. Exposure to about 75 rems over a few days is enough to cause radiation poisoning, and about 500 rems over a few days is fatal. Jupiter itself,
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