For information on one of the planets please click on one of the links below

Jupiter.

Jupiter is the largest of all the planets in the solar system. It is quite right that it is named after the Roman King of the Gods. Jupiter is so massive that, by itself, it accounts for more than 70% of the mass of all the planets in the solar system. It gives off more energy than it gets from the Sun, it has storms that are big enough to swallow up a few planet Earths and that have lasted for over 340 years, and it could possibly have life.

Jupiter takes about 11.86 years to do a complete loop around the Sun. Maybe this 11.86 year cycle is related to the roughly 11-year sunspot cycle of the Sun - Jupiter does have a magnetic field 100 times stronger than the Earth’s. Jupiter spins on its own axis faster than any other planet - its "day" is slightly less than 10 hours long! This is why Jupiter looks "flattened" at the Poles. Some of the surface winds have been clocked at over 400 km/hr.

Jupiter is about 150,000 km across, about one tenth of the size of the Sun. Basically, it is a giant ball of gas, with a solid core. At the centre it is solid, because of the pressure of the overlying layers. The pressure is enormous - about 45 million times more than the pressure at sea level on Earth. Above the solid core is a layer of liquid hydrogen, and then several layers of various gases, including hydrogen and helium There are also several trace gases, including unstable compounds of arsenic and phosphorus. Scientists have been trying to explain why these unstable gases are there.

Like the three other giant gas planets, Jupiter has a set of rings. These rings are very flimsy and hard to see, as compared to the magnificent rings of Saturn. There are less than 30 km thick.

One of the astonishing things about Jupiter is the Great Red Spot. It is an enormous oval - about 14,000 km by 35,000 km. It's big enough to swallow two or three of our planet Earths lying side by side! This strange weather pattern is incredibly stable. It has looked practically the same ever since it was first seen over 340 years ago. It actually stands some 8 km above the surrounding atmosphere - roughly the height of Mt. Everest. As is proper for the King of the Planets, Jupiter has its own collection of about 30+ satellites. One of them, Io, has as many as 8 volcanoes erupting at a time. Some of these eruptions reach up more than 100 km!

Some of the moons are bigger than our own Moon. Some of them are covered with water ice - and they probably have oceans of water under the ice, and maybe even living creatures in this water. These moons would get most of their energy from Jupiter, not the Sun.