In today's Crash Course Astronomy, Phil takes a look at the explosive history of our cosmic backyard. We explore how we went from a giant ball of gas to the system of planets and other celestial objects we have today. This episode is sponsored by Squarespace: Check out the Crash Course Astronomy solar system poster here: -- Chapters: Introduction 00:00 Geocentrism vs Heliocentrism 0:51 Makeup of the Solar System 2:38 Is Pluto a Planet? 3:14 Our Solar System 4:24 How Our Solar System Formed 5:36 Planet Formation Depends on Distance to Sun 7:14 Review 8:57 -- PBS Digital Studios: Follow Phil on Twitter: Crash Course is on Patreon! You can support us directly by signing up at Want to find Crash Course elsewhere on the internet? Facebook - Twitter - Instagram - CC Kids: -- PHOTO/VIDEO CREDITS Sun: [credit: NASA/ESA] Jupiter: [credit: NASA/ESA] Geocentric celestial spheres; Peter Apian's Cosmographia (Antwerp, 1539): #mediaviewer/File: Ganymede: : Mercury: [credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington] Understanding Solar System Dynamics: Orbits and Kepler's Laws (2008): Mercury: Venus: Earth: Mars: Jupiter: Saturn: %20Years%20at%20Saturn/ [credit: Photo by NASA/JPL/Space Science Institute/Gordan Ugarkovic] Uranus: Neptune: [credit: JHUAPL/SwRI/Dan Durda] Bennu’s Journey: Artist's impression of a protoplanetary disk: #mediaviewer/File:Artist%E2%80% Rocky Ring of Debris Around Vega: [image credit: NASA/JPL-Caltech] Proplyds in the Orion Nebula: