Profile
Settings
Refer your friends
Sign out
What is a Satellite?
A satellite can be referred to as an object that goes into space and orbits around other more significant objects. Satellites can be artificial (made by humans) or natural. Satellites can receive signals from Earth and retransmit those signals back using a transponder which works as a receiver and transmitter of radio signals.
What is an Orbit?
Planets and objects take a curved path to move around another planet, star or moon. This curved path is known as an Orbit.
Satellite
As we now know what a Satellite is, let us discuss its uses. Satellites are used for various purposes; some of them are listed below:
- Television – Television signals are sent by Satellites directly to homes.
- Telephones – In-flight phone communications on aeroplanes are provided by Satellites. Satellites also work as a channel for voice communication in rural areas and in places where phone lines are damaged.
- Navigation – Navstar: Global Positioning System (GPS) is a Satellite-based navigation system. GPS helps us to find locations on Earth.
- Weather – Satellites provide meteorologists with the ability and information to check the weather on a global scale and follow the effects of phenomena, such as volcanic eruptions, burning gas, etc.
- Climate and Environmental Monitoring – Satellites are the best sources for climate change research to gather information and data. They can determine long-term patterns of vegetation cover, rainfall, emission of greenhouse gases, etc.
A satellite successfully orbits the Earth when the pull of Earth’s gravity balances its speed, and in the absence of this balance, the satellite would fly in tangent off into space or fall back to Earth. Satellites orbit Earth at different speeds, heights and along different paths. The two most common types of orbits are “geostationary” and “polar”.
An orbiting satellite’s motion can be described by the same motion characteristic of any object that is in a circular motion. The satellite’s velocity would be directed tangent (in a straight line) to the circle at every point along its path. The satellite’s acceleration would be directed towards the centre of the circle, which is towards the central body that it is orbiting. This acceleration is caused by a net force that is directed inwards in the same direction as the acceleration. This centripetal force is supplied by gravity.
Satellites require energy to move around the Earth. This energy is known as orbiting energy. The satellites that revolve around the Sun (orbits around the Sun has kinetic energy and as it is in a gravitational field, it also possesses potential energy.
Satellites in India
India has been successfully launching various ranges of satellites since 1975. Indian Space Research Organization (ISRO) is India’s State-run space agency. This state-run space agency is responsible for building, designing, launching and operating satellites. India’s first Satellite is Aryabhatta, launched in the year 1975.
Conclusion
Satellites play a vital role in our lives today and will continue to do so in the future as well. Satellites provide information about clouds, oceans, land, ice, gases in the atmosphere, volcanoes, earthquakes, etc. It has proven itself to be crucially important for scientists as this information helps them predict the weather, climate and future calamities, and take precautions. Some satellites even watch for dangerous rays coming from the Sun and explore asteroids and comets. As of the present, Satellites are looking for evidence of water on Mars.
