30 Amazing Facts in Science (Download link below)

A : Artificial satellites are given a definite path around the Earth. The Earth’s gravity holds the satellite in a path called an orbit. There are several kinds of orbits. One is Leo or Low Earth Orbit. A Leo satellite circles 160–480 kilometres (100–300 miles) above the Earth’s surface. It has to travel very fast to avoid being sucked back to the Earth by gravity. Leos travel at about 28,164 kilometres per hour (17,500 miles per hour) and can circle the Earth in less than two hours. Medium Earth Orbit or Meo satellites are placed 9,656–19,312 kilometres (6,000–12,000 miles) above the Earth. They are often used for communications of all kinds. Geos or Geostationary Earth Orbit satellites circle the Earth in 24 hours, which is the time the Earth takes to rotate once on its axis. So they seem to be fixed above one spot on the Earth. Geo satellites orbit 35,859 kilometres (22,282miles) above the Earth. They carry television signals across the world, telephone calls between countries and internet messages. They also help predict the weather.