A satellite is a moon, planet or machine that orbits a planet or star. Satellites can be mainly classified into two: Natural Satellites and Artificial Satellites.

Natural Satellites : Moon that orbits around our Earth is a natural satellite. Earth is a natural satellite since it orbits the star, The Sun.

Artificial Satellites: Artificial satellites are man made satellites which has been intentionally put into desired orbits. Based upon the orbit into which satellites are put into, these can be classified into four,

1. Low Earth orbit [180-2000 Km]
2. Medium Earth orbit[2000-35786 Km]
3. Geosynchronous orbit[35786 Km]
4. High Earth orbit[>35786 Km]

Sputnik 1 was the first artificial satellite launched into space. It was launched by the Soviet Union in 1957. The Hubble Space Telescope is an astronomical satellite launched into Low Earth Orbit in 1990.

This image is the artistic illustration of the ESA NASA Hubble Space Telescope in its orbit 600 km above the Earth.

Based upon applications , Satellites can be classified as :

• Communication satellite,
• Astronomy Satellite,
• Atmospheric studies satellite,
• Navigation satellite,
• Reconnaissance satellite,
• Remote sensing satellite,
• Search and Rescue satellite,
• Weather satellite.

Image Courtesy: http://moonblink.info/File/Graphics/diagrams/SolSysOver.png

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