- A satellite is a body that orbits round a planet.
- The moon is a satellite of the earth.
- The number of satellites or moons of the planets are listed below:
Planets Number of Moons/Satellites Mercury None Venus None Mars 2 Earth 1 Jupiter 79 Saturn 82 Uranus 27 Neptune 14
Natural and Artificial Satellites
Examples of Natural Satellites (Photo Credit: SlidePlayer.com)
- All the moons that orbit the planets in our solar system are natural satellites.
- Artificial satellites are human made bodies launched by various countries and are now orbiting the earth.
- Rockets are used to place satellites is space.
- Some countries which have so far independently launched satellites that orbit the earth are:
Country Year of First Launch First Satellite Russia 1957 Sputnik 1 U.S.A 1958 Explorer 1 Britain 1964 Blue Streak France 1965 Asterix Japan 1970 Ohsumi China 1970 Dong Fang Hong 1 U.K 1971 Prospero (X-3) India 1980 Rohini Israel 1988 Ofeq Nigeria 2003 SAT 1
- Artificial satellites differ from one another in the following ways:
- Height or orbit round the earth.
- Slope of orbit.
- Speed of revolution round the earth.
An Example of an Artificial Satellite (Photo Credit: QKnowBooks.com)
Uses of Satellites
- Weather Satellites – These monitor the weather conditions in the atmosphere and supply the information to ground stations. This information helps to make accurate weather forecasts.
- Observation Satellites – are used for geographical studies such as photographing of areas, map making, census, and locating mineral deposits, etc.
- Communication Satellites – These satellites are sent into space for the purpose of sending information from one place to another.
- Reconnaissance Satellites – They are used for military or intelligence purposes such as locating enemy locations or troop movement.
Nigerian Surveillance Satellite
- Nigeria’s SAT 1 is called a surveillance satellite.
- It is used to observe happenings on the ground and also for geographical mappings of boundaries between states.