Kepler’s First Law, also known as the law of ellipses, describes the shape of planetary orbits around the sun. It states that planets move in elliptical paths with the sun at one of the two foci of the ellipse.
Where:
- is the distance between the Sun and the planet.
- is the semi-latus rectum (half the length of the chord through the focus parallel to the conic section’s directrix).
- is the eccentricity of the orbit.
- is the true anomaly (angle between the planet, the focus, and the perihelion point).