Artificial Satellites

SNC1D

Satellites

Satellite: an object that orbits another object

The Earth has one natural satellite: the Moon.

There are over 1000 man-made artificial satellites currently orbiting Earth.

Uses

How do satellites stay up?

Orbits

Earth-observing satellites and the International Space Station are in Low Earth Orbit (LEO).

Low Earth Orbits are fast.The ISS orbits once about every 90 minutes.

Orbits

To observe the entire Earth, a satellite is placed in a polar orbit. Since the Earth rotates, it observes a different slice of the Earth on each orbit.

Orbits

Satellites that are part of the Global Positioning System (GPS) network are more distant, in Medium Earth Orbit (MEO).

Orbits

Communication satellites often stay over one position on the Earth in geostationary orbit (GEO).

Orbits

For the orbit to take 24 hours, the satellite needs to be far above Earth, which gives the satellites wide area coverage.

Satellites do gradually lose energy and de-orbit.