The Planets

The Planets

A planet is a fairly large object that has a star as the focus of its orbit. Historically, the Sun has been considered to have nine planets. The four inner terrestrial planets are Mercury, Venus, Earth and Mars. The four gas giants are Jupiter, Saturn, Uranus and Neptune. The controversial ninth planet, Pluto, may be just a large inner member of the Kuiper Belt of asteroids. The terrestrial planets are small rocky bodies relatively close to the sun. They tend to have few or no moons. The gas giants are big cold balls of gas with small rocky cores. They tend to have many moons. The distance between the Sun and various planets is given in Astronomical Units or AU. One AU equals the distance from the Sun to the Earth or 93 million miles. [TB] {SL}