1. Satellites Smaller bodies orbiting larger ones

2. How big are satellites? ► The moon is a satellite of earth ► The earth is a satellite of the sun ► A satellite orbits a larger body

3. Geostationary satellites ► Located above the same point of the earth’s surface ► One orbit takes 24 hours ► Approximately 42000 km from the centre of the earth ► Beyond the atmosphere – no air resistance

4. Geostationary satellites ► Signal weakens as you get nearer the poles which are dead zones Earth Satellite Signal

5. Spy satellites ► In polar orbit ► Lower and faster than geostationary satellites ► Pass over both poles ► Earth turning as they travel, so the entire earth can be scanned ► High resolution images

6. Polar Orbits ► Passes over the poles

7. GPS ► Global positioning system ► Mainly geostationary, backed up with others. ► Military and civilian uses ► Up to 30m accuracy