- Jupiter is the largest planet in the Solar System. In fact, the other major planets would fit inside it and still leave room to spare.
- Jupiter’s diameter is 142,984 km, 11 times the diameter of Earth. Its mass is 1.900e27 kg – that’s 318 times that of Earth.
- The gravity on Jupiter is around 2.4 times that of Earth, meaning you’d be more than twice as heavy on its surface.
- Jupiter is a very bright object and can often be seen in the night sky without the aid of binoculars. This is partly because of its size, but also because it’s reflective.
- Jupiter has the fastest day of any Solar System planet, completing its rotation in a little under ten hours.
- Jupiter’s orbit around the Sun is elliptical. A complete orbit around the Sun takes Jupiter approximately 12 Earth years.
- Jupiter has 63 satellites but the best known of those are the four largest Galilean moons: Io, Ganymede, Europa and Callisto.
- Circular winds are a famous feature of Jupiter, notably the Great Red Spot, which is thought to be a storm that has lasted centuries.
- Jupiter is an uninhabitable gas planet, as dense clouds of mostly helium and hydrogen make up its composition.
- Jupiter radiates out double the energy it gets from the Sun, which suggests it has a very high core temperature.
- Jupiter has its own set of rings. However, these are darker and smaller than those of Saturn, and were not discovered until the late 1970s.
- Jupiter is named after the Roman king of the Gods (Zeus is the Greek equivalent). Its moons are named for those significant to him.
For more details on the planet and its satellites, read the Open University’s free course unit Jupiter and its moons, and also NASA’s World Book article Jupiter.
Sources
Jupiter and its moons, Open University Learning Space website, accessed: 22nd March 2009, author: Rothery, D.
Chapter 9, Teach Yourself Planets, published by Hodder Education in 2003, author: Rothery, D.
Jupiter, World Book at NASA website, published 2004, accessed: 22nd March 2009, authors: Gierasch, P.J. and Nicholson, P.D.
Teach Tourself Planets (Teach Yourself)

















