Being a kid, a question that always haunted my mind was, when I walk at night why is the moon always moving with me in my direction? If we look into the scientific reason now, we can reason it out. Satellite can be defined as celestial body that surrounds any planet and rotates around it. For example, moon is a satellite that surrounds Earth and rotates around it. Any satellite has its own independent orbit. There are two types of satellites – Artificial satellite and natural satellites.
Natural satellites are the one which preexist in universe. For instance, moon is a natural satellite that surrounds Earth.
These are man-made satellites that have been projected into the solar system to surround some planet for some particular purpose. These are the reasons behind that we are able to view live cricket matches, existence of dish televisions. These satellites communicate with Earth by using radio waves to send signals to antenna attached to Earth. The antennas catch hold of these signals, interpret them, get the information and process it in the form that can be understood by the human mind. One example of artificial satellite being, satellite sent to Mars from Earth to study about the existence of life on Mars.
IMPORTANCE OF SATELLITES
Since satellites are projected at a much larger distance from Earth, they have a full view of larger areas of Earth at any instance. This allows them to collect more information about these areas than any other object which is grounded on Earth would do. Satellites can see a larger surface area. This information collected by satellite is more accurate and quicker. One more reason being: since they are above cloud, they are able to neglect dust and molecules in the atmosphere that acts as an obstruction.
HISTORY ABOUT SATELLITES
The first satellite in space that was launched by Soviet Union in 1957 was Sputnik 1. NASA has launched lots of satellites since its inception. It started with Explorer 1 satellite in 1958 (USA’s first artificial satellite). It had a sensor that could measure high-energy particles in space called cosmic rays. NASA then continues in its series of expeditions and launched Explorer 6 in 1959. Explorer 6 gave the first picture of Earth. It was followed by TIROS-1 in 1960 which gave first TV picture of Earth from space.