Kepler’s laws of planetary motion reshape how humans understand the solar system
Kepler’s laws of planetary motion emerged between 1609 and 1621, when a German mathematician working with a dead Danish astronomer’s data realized the planets don’t move in circles. Studying Mars, Johannes Kepler found an eight-arc-minute discrepancy he refused to ignore, and followed it to elliptical orbits. Four centuries later, NASA still uses his math to plot spacecraft trajectories.









