Kepler's Laws of Planetary Motion

Three empirical laws of orbits: ellipses, equal areas in equal times, and the period-distance relation.

Core Principles & Analysis

• Distilled from Tycho Brahe’s decades of naked-eye Mars observations.
• The first two laws appeared in Astronomia Nova (1609), the third in Harmonices Mundi (1619).
• Newton’s derivation of all three from universal gravitation was the decisive test of his theory.

Specifications & Metrics

• SYMBOL: T² ∝ a³