Asteroids: Crash Course Astronomy #20

Now that we’ve finished our tour of the planets, we’re headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of smallish planets but were destroyed after collisions. Most orbit the Sun between Mars and Jupiter, but some get near the Earth. The biggest, Ceres is far smaller than the Moon but still big enough to be round and have undergone differentiation. CORRECTION: In the episode we say that 2010 TK7 is 800 km away. However, 2010 TK7 stays on average 150 million kilometers from Earth, but that can vary wildly. Sorry about that! -- Table of Contents Asteroids Are Chunks of Rock, Metal, or Both 1:45 Most Orbit the Sun Between Mars and Jupiter 7:16 Ceres is Far Smaller Than the Moon, But Large Enough to be Round 3:43 -- PBS Digital Studios: http://youtube.com/pbsdigitalstudios Follow Phil on Twitter: https://twitter.com/badastronomer Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Patreon: http://www.patreon.com/crashcourse -- PHOTOS/VIDEOS Timelapse of Asteroid 2004 FH's flyby http://en.wikipedia.org/wiki/File:Asteroid_2004_FH.gif [credit: NASA/JPL Public Domain] Asteroid Discovery Video https://www.youtube.com/watch?v=2k2vkLEE4ko [credit: Scott Manley - scottmanley1972@gmail.com] Inner Solar System http://en.wikipedia.org/wiki/File:InnerSolarSystem-en.png [credit: Wikimedia Commons] Kirkwood gaps http://commons.wikimedia.org/wiki/File:Kirkwood-gaps-as-disk.png [credit: Wikimedia Commons] Ceres, Earth & Moon size comparison http://en.wikipedia.org/wiki/File:Ceres,_Earth_%26_Moon_size_comparison.jpg [credit: NASA] Dawn Glimpses Ceres’ North Pole http://www.jpl.nasa.gov/news/news.php?release=2015-133 [credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA] Ceres cutaway http://commons.wikimedia.org/wiki/File:Ceres_Cutaway.jpg [credit: NASA, ESA, and A. Feild (STScI)] Bright Spot on Ceres Has Dimmer Companion http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA19185 [credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA] Vesta http://en.wikipedia.org/wiki/4_Vesta#/media/File:Vesta_full_mosaic.jpg [credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA] Lutetia http://en.wikipedia.org/wiki/21_Lutetia#/media/File:Lutetia_closest_approach_(Rosetta).jpg [credit: ESA] Gaspra http://commons.wikimedia.org/wiki/File:Galileo_Gaspra_Mosaic.jpg [credit: NASA] Steins http://neo.ssa.esa.int/image/image_gallery?uuid=db747cf5-9d21-405e-bcdb-e70fe475edc9&groupId=10157&t=1340734455649 [credit: ESA/Osiris] Mathilde http://neo.jpl.nasa.gov/images/mathilde1.jpg [credit: NEAR Spacecraft Team, JHUAPL, NASA] Ida http://en.wikipedia.org/wiki/243_Ida#/media/File:243_ida_crop.jpg [credit: NASA/JPL] Kleopatra http://apod.nasa.gov/apod/ap000510.html [credit: Stephen Ostro et al. (JPL), Arecibo Radio Telescope, NSF, NASA] An artist's conception of two Pluto-sized dwarf planets in a collision around Vega. http://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets#/media/File:Massive_Smash-Up_at_Vega.jpg [credit: NASA/JPL-Caltech/T. Pyle (SSC)] Itokawa http://apod.nasa.gov/apod/ap140209.html [credit: ISAS, JAXA] An artist's illustration showing two asteroid belts and a planet orbiting Epsilon Eridani http://en.wikipedia.org/wiki/Epsilon_Eridani#/media/File:NASA-JPL-Caltech_-_Double_the_Rubble_(PIA11375)_(pd).jpg [credit: NASA/JPL-Caltech] Near-Earth Asteroids http://www.jpl.nasa.gov/images/asteroid/20130204/asteroid20130204-full.jpg [credit: NASA/JPL-Caltech] Lagrange Points Diagram http://en.wikipedia.org/wiki/Trojan_(astronomy)#/media/File:Lagrange_very_massive.svg [credit: Wikimedia Commons] TK7 http://en.wikipedia.org/wiki/2010_TK7#/media/File:PIA14405-full_crop.jpg [credit: NASA/JPL-Caltech/UCLA] 165347 Philplait http://www.slate.com/content/dam/slate/blogs/bad_astronomy/2014/01/20/asteroidphilplait_panstarrs.jpg.CROP.original-original.jpg [credit: Larry Denneau/Pan-STARRS via Amy Mainzer]