Outer Planets

The four giant planets which come next in order of distance from the Sun - Jupiter, Saturn, Uranus and Neptune, are called the major planets or the outer planets.

Jupiter

Jupiter is the giant among the planets. Its mass is 71 percent of the total mass of the planets. It has one and a half times the volume of all the other planets combined. But its mean density is only one-fourth of the Earth's.

Much of Jupiter's mass is made up of atmosphere which is estimated to be some 40225 kilometre deep. The atmosphere consists largely of hydrogen and helium which explain the low density of the planet.

Jupiter has 63 satellites.

Saturn

Saturn, nine times larger across than the Earth, is the outermost planet visible to the naked eye. With a rocky core of the size of the Earth, Saturn is the second largest planet (next to Jupiter).

The most spectacular feature of Saturn is its system of Rings. Saturn has the second biggest family of Satellites, a total of 61.

Uranus

Uranus is not visible to the unaided eye, but may be seen through good field glasses. It has five satellites.

Neptune

Neptune, between 4600 and 4300 million kilometres from the Earth, is also visible through good field glasses. It is denser and little smaller than Uranus. 

Neptune has only two satellites.

Neptune takes 165 years in making one revolution around the Sun but it completes one rotation in 16 hours.

Pluto

Pluto is visible only through a telescope, as a light spot of the 14th or 15th magnitude.

This maverick planet, the farthest, the smallest, the darkest, and the coldest, follows the most elongated and tilted orbit in the solar system.