Satellite

satellite is an object in space that orbits another body, such as a planet. The Moon is a natural satellite of Earth. An artificial satellite is a small spacecraft sent into orbit from Earth.

Artificial satellites are used for com­munication, weather forecasting, navi­gation, military surveillance, and scien­tific research. A satellite remains in orbit because of the gravitational pull of the larger body around which it travels. Any spacecraft orbiting Earth is technically a satellite, although manned spacecraft are not usually referred to as satellites. The International Space Station is the biggest artificial satellite. The Hubble

Space Telescope also is a satellite. There are about 2,500 satellites orbiting Earth, and others have been placed in orbit around the Moon, Venus, and Mars.