Explore how human understanding of planetary orbits has changed throughout history in this video about Kepler's laws of planetary motion. Kepler's three laws of planetary motion accurately describe the elliptical orbits of objects around the Sun. This video presents the story of Johannes Kepler and Tycho Brahe, who worked together at the turn of the seventeenth century. Animations show the geocentric model of the solar system (in which Earth was believed to be the center) and the heliocentric model (in which the Sun is the center).This video is available in both English and Spanish audio, along with corresponding closed captions.