Kepler's three laws of planetary motion define the elliptical orbits of planets, the area-speed relationship during orbits, and the mathematical relationship between a planet's orbital period and its orbit's size.
Kepler's Laws of Planetary Motion
Johannes Kepler formulated three laws that describe the motions of planets in the solar system. These laws are:
- Kepler's First Law: States that planets orbit the Sun in elliptical paths, with the Sun at one focus of the ellipse.
- Kepler's Second Law: Also known as the Law of Equal Areas, this law declares that a planet sweeps out equals areas in equal times during its orbit, implying that the planet's velocity varies depending on its distance from the Sun.
- Kepler's Third Law: Indicates that there is a proportional relationship between the square of a planet's orbital period and the cube of the semi-major axis of its orbit, mathematically expressed as P² ≈ a³ where P is the orbital period and a is the semi-major axis.
Kepler's laws enhanced the understanding of celestial mechanics and paved the way for Isaac Newton's work on universal gravitation.