Jupiter belongs to the outer part of the solar system. The space probes Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2 visited Jupiter. It is one of four planetary giants: Saturn, Jupiter, Uranus en Neptune. We can only see the thick atmosphere of these giants. We cannot observe the surface, if there is any.
This is an image of the atmosphere of Jupiter	Jupiter is the next to one biggest planet in our solar system. Its mass is 318 times that of the earth and its diameter is 142 800 km, 11 times that of the earth. Astronomers are pretty sure that Jupiter for the biggest part is made of hydrogen and helium.
It rotates in 0,41 earthly day, that is about 10 hours. Its orbit around the sun takes 11,9 years. Deep in the atmosphere at a depth of several km the pressure becomes so high that the gasses are compressed to the liquid state. Jupiter is often referred to as gas-giant but liquid-giant would be better. It has a very powerful inner energy source. That is the reason that astronomers had the idea that the planet represented a failed companion star of the sun. It became clear that this notion was wrong.	Another image
	The cloud cover of the planet is spectacular. The colors vary from white and orange to blue and brown. They are continuously moving with great speed. Most visible clouds are made of crystals of frozen ammonium. The temperature of the highest clouds is about minus 130 degrees Celsius.