Jupiter Facts The planet Jupiter is the fifth planet out from the Sun, and is two and a half times more massive than all the other planets in the solar system combined. It is made primarily of gases and is therefore known as a “gas giant”. read more
If Jupiter had become 80 times more massive, nuclear fusion would have occurred in its core. Had that happened, it would have become a star instead of a planet. More information and facts about Jupiter. What is even more provocative is the theory that Jupiter is a failed star. read more