Welcome to the first episode of Crash Course Astronomy. Your host for this intergalactic adventure is the Bad Astronomer himself, Phil Plait. We begin with answering a question: "What is astronomy?" Check out the Crash Course Astronomy solar system poster here: null -- Chapters: Introduction 00:00 What is Astronomy? 3:00 Who Studies Astronomy? 3:50 Origins of Astronomy 5:27 Astrology vs Astronomy 6:19 Geocentrism 7:51 Revolutions in Astronomy 8:58 Astronomy Today 10:26 Review 11:29 -- PBS Digital Studios: null Follow Phil on Twitter: https://twitter.com/badastronomer Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Instagram - https://www.instagram.com/thecrashcourse/ CC Kids: null -- Photos: http://commons.wikimedia.org/wiki/File:Earth_cutaway.png http://en.wikipedia.org/wiki/Earth%27s_magnetic_field#mediaviewer/File:Geodynamo_Between_Reversals.gif http://en.wikipedia.org/wiki/Geomagnetic_storm#mediaviewer/File:Magnetosphere_rendition.jpg http://en.wikipedia.org/wiki/Saturn#mediaviewer/File:Saturn_PIA06077.jpg http://en.wikipedia.org/wiki/243_Ida#mediaviewer/File:243_Ida_large.jpg http://commons.wikimedia.org/wiki/File:Comet_Hale_Bopp_NASA.jpg http://solarviews.com/raw/comet/kuiper3.jpg http://solarviews.com/cap/comet/kuiper3.htm http://en.wikipedia.org/wiki/List_of_nearest_bright_stars#mediaviewer/File:3_Solar_Interstellar_Neighborhood_(ELitU).png http://www.slate.com/blogs/bad_astronomy/2013/06/28/planetary_nebula_sh2_68_the_flaming_skull_nebula.html http://www.slate.com/blogs/bad_astronomy/2013/06/06/milky_way_galaxy_two_new_discoveries_about_its_spiral_arms.html http://en.wikipedia.org/wiki/Black_hole#mediaviewer/File:PIA16695-BlackHole-Corona-20130227.jpg http://commons.wikimedia.org/wiki/File:Messier_69_HST.jpg http://www.slate.com/blogs/bad_astronomy/2013/06/25/nearby_galaxies_swift_uv_pictures_of_two_galactic_neighbors.html http://upload.wikimedia.org/wikipedia/commons/0/0f/Earth%27s_Location_in_the_Universe_SMALLER_%28JPEG%29.jpg http://www.slate.com/blogs/bad_astronomy/2013/03/21/age_of_the_universe_planck_results_show_universe_is_13_82_billion_years.html http://www.esa.int/spaceinimages/Images/2007/02/True-colour_image_of_Mars_seen_by_OSIRIS http://en.wikipedia.org/wiki/Andromeda_Galaxy#mediaviewer/File:WISE-_Andromeda.jpg http://en.wikipedia.org/wiki/Triangulum_Galaxy#mediaviewer/File:VST_snaps_a_very_detailed_view_of_the_Triangulum_Galaxy.jpg http://en.wikipedia.org/wiki/Hubble_Space_Telescope#mediaviewer/File:HST-SM4.jpeg http://www.slate.com/blogs/bad_astronomy/2013/12/21/winter_solstice_2013_the_shortest_day_of_the_year.html http://www.slate.com/blogs/bad_astronomy/2012/12/28/full_moon_today_is_the_13th_full_moon_of_2012.html http://en.wikipedia.org/wiki/Nicolaus_Copernicus#mediaviewer/File:Nikolaus_Kopernikus.jpg http://en.wikipedia.org/wiki/Tycho_Brahe#mediaviewer/File:Tycho_Brahe.JPG http://en.wikipedia.org/wiki/Johannes_Kepler#mediaviewer/File:Johannes_Kepler_1610.jpg http://en.wikipedia.org/wiki/Isaac_Newton#mediaviewer/File:GodfreyKneller-IsaacNewton-1689.jpg http://en.wikipedia.org/wiki/Galileo_Galilei#mediaviewer/File:Justus_Sustermans_-_Portrait_of_Galileo_Galilei,_1636.jpg http://www.slate.com/blogs/bad_astronomy/2012/09/25/revealing_the_universe_the_hubble_extreme_deep_field.html