Nobody knows why or how.
The planets move on little circles that move on bigger circles.
He was certain that all planets moved in a uniform, orderly manner, and his contemporaries figured that meant it had to be in circles because in circles there is no beginning and no end.
coins wheels planets and so on ...
ptolemy did something
Circle around the sun some say the sun circles the planets but it does not
Johannes Kepler, using measured planetary positional data provided by Tycho Brahe, showed that the orbits of the planets were ellipses ("flattened circles"), with the Sun at one focus of the eliipse.
It makes them go round in circles.
The revolution of the planets about the sun, but he wanted to use circles.
In the Ptolemaic system, the motions of Mercury, Venus, Mars, Jupiter, and Saturn were described with epicycles. These epicycles were small circles that the planets were thought to move in while also orbiting the Earth on larger deferent circles.
Johannes Kepler
to explain the motion of planets, especially the phenomenon of retrograde motion where planets appear to temporarily reverse their direction of motion. Ref: Andrew Liddle "An Introduction to modern Cosmology".
Planets travel around the Sun in elliptical orbits due to the gravitational pull of the Sun. This gravitational force keeps the planets in their respective paths, causing them to move in a continuous loop around the Sun. The speed at which a planet travels around the Sun depends on its distance from the Sun and the mass of the Sun.