Kepler formulated the three laws of planetary motion from observations made by the Danish astronomer Tycho Brahe of the orbit of Mars.
These laws were enunciated to mathematically describe the movement of the planets in their orbits around the Sun. However, the scientific resources existing in his time did not allow him to prove these laws. It was Newton who did it after having developed the Differential and Integral Calculus and formulating the Laws of Universal Gravitation.
Aristotle mistakenly thought that the Earth was the center of the universe, thus establishing a geocentric cosmological model.
According to this model, Aristotle proposed that the universe (the cosmos) was spherical and finite, with the Earth immobile at its center, composed of the four fundamental elements (made up of spherical layers): ground, water, air and fire; and the Sun along with the fixed planets in their respective concentric spheres revolving around the Earth. The outermost sphere being that of the stars and all these external elements being made of a fifth element which he called ether.
