While earlier astronomers like Nicolaus Copernicus proposed a heliocentric model where planets revolved around the Sun, they still assumed circular orbits. Kepler, through meticulous analysis of Tycho Brahe's extensive astronomical observations, formulated his three laws of planetary motion:
1. Law of Orbits: Planets move in elliptical orbits with the Sun at one focus.
2. Law of Areas: A line connecting a planet to the Sun sweeps out equal areas in equal times.
3. Law of Periods: The square of a planet's orbital period is proportional to the cube of its average distance from the Sun.
Kepler's groundbreaking work published in the early 17th century revolutionized our understanding of planetary motion and laid the foundation for Isaac Newton's later work on universal gravitation.
