Theories of Planetary Motion

Theories of planetary motion describe how planets move around the Sun. Early ideas, like Ptolemy's, saw planets moving in complex loops. Copernicus proposed the Sun at the center, with planets orbiting in circles. Kepler improved this with laws showing planets move in elliptical (oval) paths, speeding up and slowing down as they get closer or farther from the Sun. Newton later explained these motions through gravity, showing that a force between the Sun and planets causes them to stay in orbit, similar to how an apple falls from a tree. These theories collectively explain the predictable and precise paths planets follow.