Age of DiscoveryScience & Math Kepler's laws of planetary motion 1609Turning point Planets move in ellipses, not perfect circles. The heavens obey mathematical laws. ▲ MattersSaveShareTrace roots Longest chain: The Big Bang → First stars ignite → Supernovae seed heavy elements → The Sun forms → Earth forms → First oceans → First life → Photosynthesis evolves → Great Oxidation Event → Complex cells (eukaryotes) → Multicellular life → First animals → Cambrian Explosion → First vertebrates → Jawed fish → Fish walk onto land → The amniotic egg → The Great Dying → Dinosaurs appear → Asteroid ends the dinosaurs → Early primates → Apes split from monkeys → Human line splits from chimpanzees → Walking upright → First stone tools → Genus Homo appears → Homo erectus → Control of fire → Habitual fire and cooking → Homo sapiens appears → Complex language → Natufian villages → Oldest known bread → Agriculture begins → Irrigation → Uruk and the first cities → Cylinder seals → Writing (cuneiform) → Babylonian mathematics → Babylonian astronomical diaries → Thales and natural philosophy → Trial and death of Socrates → Plato's Academy → Euclid's Elements → Hipparchus and trigonometry → Ptolemy's Almagest → Copernicus' heliocentric model → Tycho Brahe's observations → Kepler's laws of planetary motion Community notesLoading notes… Learn more ranked by votesDocumentplato.stanford.eduJohannes Kepler (Stanford Encyclopedia of Philosophy) ↗Editor's pickDocumentbritannica.comKepler's laws of planetary motion (Britannica) ↗Editor's pickBookArthur KoestlerThe Sleepwalkers ↗Editor's pickVideoSearch on YouTubeKepler's laws explained ↗Editor's pick