Jupiter is the largest planet in our solar system.
It is a gas giant composed primarily of hydrogen, helium, methane and ammonia
The density of the gas increases at great depths, until it turns into a liquid and there is a rocky core in the middle thought to be twice the size of Earth.
The upper layers of gas can be seen to be very active with huge storm like features. Jupiter contains the largest storm of any planet called the Great Red Spot. This storm is known to have existed for at least 336 years, when it was first spotted by Robert Hooke. This kind of storm is visible on all the gas giants, and it is unknown what causes them or why they last so long.
Jupiter has an amazing array of satellites with various properties. The main Satellites are Io, Europa, Ganymede and Callisto and are collectively known as the Gallilean Satellites. Io is the closest of the four and is the most volcanicaly active body in the Solar System. It is thought the position of Io, i.e. between Jupiter and the other Galillean Satellites, is causing Io to be squashed and squeezed by gravitational forces. This inturn causes friction to heat Io`s core and so keeps it predominantly in a molten state.
The next of the Galillean Satellites is Europa, the smallest of the four. It is encased in a shell of ice, and there is a debate whether beneath the ice there is a sea of water. If there is then this body could be the best hope for finding life elsewhere in the Solar System. Nasa is reportedly designing a mission to travel to Europa within 10 years to analyze this hypothesis.
Moving on from Europa we have Ganymede, the largest of the Galillean Moons. It is the largest Moon in the Solar System and at 5260 km diameter is even larger than Mercury. It has a rocky cratered surface covered with ice with no or negligable external activities.
The last of the Galillean Satellites is Callisto, similar in appearance to Ganymede, it has a diameter of 4600 km and also has a rocky cratered surface covered in ice that has seen many bombardments in its life.
Planetary Information
| Maximum Distance from the Sun | 814MKms |
| Minimum Distance from the Sun | 741MKms |
| Diameter | 143884 km |
| Mass | 318 |
| Sidereal period | 11.86y |
| Rotation period | 9h 55m |
| Velocity | 13 km/s |
| Gravity | 2.64 |
| Mean Temperature | -50 C |
| Number of Moons | 17 |
| Escape Velocity | 214500 km/h |