What is a Satellite?

Anything that revolves around Earth or another body in space in a circular or elliptical path is called as "Satellite".It can be a planet or a machine.

Example: Earth and the moon are  natural satellites. 

                  Sputnik 1, Explorer 1 are man-made satellites(artificial satellites).

Satellites are in many shapes and sizes.Commonly most satellites contains two parts namely,  an antenna and a power source. 

- The antenna sends and receives information, often to and from Earth. 
- The power source can be a solar panel or battery. Solar panels make power by turning sunlight into electricity. 

Satellites are generally propelled by rockets for launching into space.

Artificial satellites carry cameras and scientific sensors  and are used to  

* take pictures of our home planet and  provides information about clouds, oceans,air, land,ice that help meteorologists predict weather and track hurricanes.

 take pictures of other planets, the sun, black holes, dark matter or faraway galaxies that help scientists better understand the solar system and universe. 

*monitor wildfires, volcanoes and their smoke.

* monitor space to collect data from the solar system and universe. ,explore asteroids, comets and more.


Satellites are also used  for communications, such as beaming TV signals and phone calls around the world. TV signals and phone calls are sent upward to a satellite. Then, almost instantly, the satellite can send them back down to different locations on Earth. 

Satellites used for communications is called Communication Satellite or Comsat.

A group of more than 20 satellites make up the Global Positioning System(GPS). If you have a GPS receiver, these satellites helps to figure out your exact location. 

Natural Satellites works continuously without a break.

Do you know Why?

Day and Night,Time,Climate everything will get affected if this natural satellites slows down or stops its work.


sputnik satellite
Credits:NASA
Earth,a  natural satellite orbits the sun  because of the pull of the Sun's gravity.The gravity of the Sun keeps earth in their orbit. Earth takes one year to revolve around the sun.Earth takes 24 hrs(a day) to rotate on its axis from west to east. The Earth revolves around the Sun at a speed of about 18.5 miles/sec (30 km/sec)

Moon ,a  natural satellite orbits Earth because of the pull of Earth's gravity.The Moon takes about 27 days to orbit the Earth.The moon orbits Earth at an average speed of 2,288 miles per hour (3,683 kilometers per hour).It travels at different speeds during different parts of its orbit. It moves slowest when it is at furthest distance from Earth.It moves fastest in its orbit when it is closest to Earth.