Satellites are objects that orbit another object due to gravitational pull. They can be natural or man-made, and there are over 10 types of artificial satellites. Satellites can be classified by type, height, orbit, and primary object. The International Space Station is the largest artificial satellite, and there are currently around 5,000 artificial satellites orbiting the Earth.
A satellite can be defined as any object, man-made or natural, that orbits something else. For example, the moon orbits the Earth, so it satisfies this definition. The Earth is a satellite of the sun. Other natural examples include comets, stars, asteroids and other planets.
The orbit is determined by the gravitational pull of the object around which the other body rotates. The thing that a satellite revolves around is called the primary object. However, primary objects are also affected by their satellites and feel some of their gravitational pull. In some cases, when two objects have similar size and mass and similar gravitational attraction, they can be called binary systems. Some argue that the moon Charon and Pluto represent a binary system instead of a primary object and a satellite, as both have similar masses.
Most are more familiar with the term in relation to the many satellites circling the earth. Sputnik was the first artificial satellite, launched in 1957 by the Soviet Union. The launch of Sputnik is almost analogous to the start of the Space Race that followed between the US and the USSR. In today’s climate, however, many countries have found that a cooperative effort is more successful in space exploration and studies. The International Space Station, which orbits the Earth, is currently the largest artificial satellite in space and represents the cooperative effort of several countries.
Artificial satellites are classified by type and there are more than ten types. Some of the major types used today include astronomical, communications, Earth observation, and weather satellites, and space stations. Others include those used to monitor the Earth militarily and biosatellites, which can carry animals or other life forms for research into Earth’s life forms in space. Navigation satellites are now popular and form a vital part of the global positioning system (GPS) now available in many cars.
These objects can also be classified according to the height at which they orbit the earth or another body. A satellite in low Earth orbit circles the planet at an altitude of between 0 and 1,240 miles (1,995.59 km). High Earth orbits can be up to 22,240 miles (35,791.81 km) away. Average Earth orbits represent the distance between high and low Earth orbits.
There are further distinctions to describe the type of orbit it has; for example, Pluto has a slightly elliptical orbit. It can also be classified based on the primary object it orbits. A satellite circling the Earth has a geocentric orbit, for example. The Earth and the planets of this solar system are classified as having a heliocentric orbit as they surround the sun.
An artificial satellite can serve many purposes. People currently use many different systems to keep track of things like the weather, to operate cell phones, to find out how to get somewhere, and to gather more information about the Earth and the galaxy. About 5,000 artificial satellites currently orbit the Earth, and on clear, dark nights, you can often see one in the night sky. Of course, planets, stars and comets are also satellites. People should also remember that the Earth is not stationary in the sky, as it orbits the sun.
Protect your devices with Threat Protection by NordVPN
