Kepler's First Law8.4 -Understand Kepler's laws of planetary motion
Law #1. Planets move in elliptical orbits around the Sun.
They do not move in circular orbits. Before Kepler astronomers did not recognise this and so their computations were flawed.
An ellipse is an oval shape with two foci (a focus). The Sun is at one focus and the other is in space.
Mix & Match
- Bill Drennon, Central Valley Christian High School Animated Kepler's Laws
- Davidson's WebPhysics Animations
- UBC's Interactive Mathematics Interactive Simulator