Kepler's first law

Definition

Kepler's first law, also known as the law of orbits, states that all planets move in elliptical orbits around the Sun, with the Sun at one of the two foci of the ellipse.

Related terms

Kepler's second law: This law, also known as the law of areas, states that a line connecting a planet to the Sun sweeps out equal areas in equal time intervals.

Kepler's third law: Also called the harmonic law, it relates a planet's orbital period to its average distance from the Sun.

Ellipse: A closed curve resembling an elongated circle, which describes planetary orbits according to Kepler's laws.