There was a time when no one knows that why planets are stayed in the orbits. Sir Isaac Newton proved that planets and their moons were held in the solar system due to the Gravity of Sun. He was able to show the relationship between Force, mass and distance. He changed the way people think about the solar system. Though another great physicist, Einstein, thinks the idea of gravity by Newton is not completely accurate, still he was first who gives the idea of gravity. It makes other scientist to research on this topic.