The Solar System

• Mercury (rock planets)
• Venus (rock planets)
• Earth (rock planets)
• Mars (rock planets)
• (asteroid belt)
• Jupiter (gas planets) 
• Saturn  (gas planets) 
• Uranus  (gas planets) 
• Neptune  (gas planets) 
• (pluto) (rock planets)

Earth is at a 23 degree tilt, that is why we have seaons

All the planets are held in orbit by the sun's gravity

A Satellite is something which orbits a planet. 

The moon is a natural satellite of Earth. It takes 28 days for the moon to do a full orbit of Earth. The moon reflects light from the sun. IT IS NOT LUMINOUS. The moon is held next to Earth by Earth's gravity. The moon's gravity affects the tides ect.

Artificial Satellites, the four main uses:

1. Communication and Navigation. e.g. Radio, T.V, telephones

2. Weather e.g. weather forecasts

3. Observing Earth e.g. spy satellites, maps

4. Exploring the solar system e.g. the hubble telescope

These too are kept in position by gravity