Satellites

OK, maybe there's no proof of aliens yet, but that doesn't mean we aren't receiving communications from outer space!

How it Works

Electromagnetic Waves
Radio
Television
Internet

A satellite is an object that orbits around a planet, such as the moon. A communication satellite orbits around earth just like the moon, except it’s a whole lot smaller and can transmit large amounts of information to any place on earth that has a direct line of sight with it.

The first communication satellite was the Telstar, in 1962. Since then, hundreds have been launched, circling the planet thousands of miles a way. Most are located 22 279 miles above the equator, and travel 6 870 miles per hour eastward (the same way earth is travelling). They are situated in a specific spot allowing them to travel in sync with the planet. The higher the satellite the larger footprint - area it can transmit signals to - it is capable of.

How it works
Satellites can transmit telephone calls, TV signals, Internet data, and provide information for weather, navigation, and international intelligence. There are many times of satellites, but they all contain transponders, which send and receive microwave signals. In most cases, a ground antenna transmits information upto the satellite, which replicates the information and relays it at a different frequency to many antennas situated all over the planet. Each transponder can only hold a single TV channel, or upto 2600 telephone conversations. Most satellites over a dozen transponders. Information is received by a telemetry antenna, and is sent back to earth using the transponders. Other equipment is also necessary, such as a propulsion system to control the satellite’s position, and solar panels to gather energy the energy needed to transmit the signals.

Sources
Click here for a list of sources used in this project.
Glossary
All the words in bold are found in the Glossary. If you don't understand a word, click on the beside it, to go directly to the Glossary Page.
[/10005/library/satellites.html]
Unless otherwise stated, information on this site was created by The Unica Island Team, and may be reproduced for educational purposes without permission. For complete information, please see the copyright information pages.