Why are some planets so big?

The largest planets of the solar system are the planets Jupiter and Saturn. Both planets have distinct bands around them with stripes. Saturn can be recognized easily by its rings. Uranus, uniquely tilted sideways, and the blue Neptune, the coldest of the outer planets, are also much larger then the inner planets. The outer planets are so big because they are comprised mainly of gases such as helium and hydrogen. These planets have a solid core, which is surrounded by liquid or frozen gas. This reason why they are also known as 'gas giants'

Why does Saturn have so many rings?

Although the rings of Saturn can be seen clearly with a normal telescope and have been known for 350 years, nobody knows exactly how they were formed. Scientists are still trying to learn more about them. The ring system has a diameter of 278,000 km, but is only a few kilometers thick. The rings are not solid 'bands', but are believed to be made of varying sizes of comets, asteroids, and shattered moons that broke up before reaching the planet. They revolve around Saturn at different speeds.

Why does Jupiter have so many stripes?

Jupiter rotates very fast on its axis, once every 10 hours. This has formed a pattern of stripes in its atmosphere, which runs parallel to the equator. The lighter zones are warm, rising masses of clouds, and the dark ones are cold, descending clouds. This pattern is disturbed by storms. One of these, the 'large red spot', is huge and can be seen from the Earth. Jupiter is not only the biggest but also the heaviest planet. It has more than 60 moons. Four of them were detected by the Italian astronomer Galileo Galilei with a telescope as early as 400 years ago