Johannes Kepler, a renowned 17th-century astronomer, discovered the fundamental laws of planetary motion, which revolutionized our understanding of the solar system. His first law states that planets orbit the Sun in elliptical paths with the Sun at one focus.
The second law, or the law of equal areas, explains that a planet sweeps out equal areas in its orbit in equal times, indicating varying orbital speeds. His third law establishes a relationship between the orbital period and the distance of a planet from the Sun, revealing a consistent mathematical pattern. These laws laid the foundation for modern celestial mechanics.