* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Pluto_Friends
Discovery of Neptune wikipedia , lookup
History of astronomy wikipedia , lookup
Circumstellar habitable zone wikipedia , lookup
Nebular hypothesis wikipedia , lookup
Geocentric model wikipedia , lookup
James Webb Space Telescope wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Observational astronomy wikipedia , lookup
Spitzer Space Telescope wikipedia , lookup
Astrobiology wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Hubble Space Telescope wikipedia , lookup
Hubble Deep Field wikipedia , lookup
Exoplanetology wikipedia , lookup
Planetary system wikipedia , lookup
Hubble's law wikipedia , lookup
Solar System wikipedia , lookup
Extraterrestrial life wikipedia , lookup
Planetary habitability wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Clyde Tombaugh wikipedia , lookup
Astronomical naming conventions wikipedia , lookup
Eris (dwarf planet) wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
Definition of planet wikipedia , lookup
Hubble Space Telescope Max Mutchler Space Telescope Science Institute Friends School Collection February 6, 2007 Overview • Hubble mission background • Discovery of Pluto (1930) and moon Charon (1978) • Hubble observations of Pluto: discovery of moons Nix and Hydra (2005) • Planet vote of 2006: planets and “dwarf planets” • History: how many planets are there? • The “problem” of being first: Ceres & Pluto • Hubble observations of Ceres, another dwarf planet • New Horizons and Dawn missions: follow the data, not the voting • Inspiring students, and “teachable moments” Hubble was launched into orbit by the Space Shuttle in 1990 Hubble is serviced in orbit by astronauts 1993 1997 1999 2002 2008? Advanced Camera for Surveys (ACS) Installed during Hubble Servicing Mission 3B March 2002 The “Home of Hubble” Space Telescope Science Institute (STScI) on the campus of Johns Hopkins University in Baltimore Hubble observations of Ceres and Pluto What is a planet ? The discovery of Pluto in 1930 Clyde Tombaugh Blink-comparator that Tombaugh used to compare two images, and discover Pluto by it’s motion The discovery of Pluto’s moon Charon in 1978 James Christy & Robert Harrington U.S. Naval Observatory Washington, D.C. The discovery of two new moons of Pluto Weaver, Stern, Mutchler, Steffl, Merline, Buie, Spencer, Young, Young, 2006, Nature, 439 Notice the star trails, cosmic rays, chip gap… 15 May 2005, frame 1 Notice the star trails, cosmic rays, chip gap… 15 May 2005, frame 2 Dithering across the chip gap now…see anything? 15 May 2005, frame 3 Dithering across the chip gap now…see anything? 15 May 2005, frame 4 Looking for real objects among all the artifacts… 15 May 2005, sum 4 frames Hydra Nix Charon Pluto Hubble ACS image on 15 May 2005 Hydra Nix Charon Pluto Hubble ACS image on 18 May 2005 New moons are roughly 3-4x farther out than Charon, and co-planar with possible 6:4:1 orbital resonances Hydra (P1) Charon Nix (P2) 15 and 18 May 2005, median 8 frames What does a “quadruple planet” look like? http://www.stsci.edu/~mutchler/pluto_50.html Animations produced with Celestia Relative sizes of Pluto, Charon, and new moons Nix Hydra 2300 km 1200 km ~100 km The new moons are roughly 12x smaller and 600x fainter than Charon, and 4000x fainter than Pluto Common origin of Pluto and all 3 moons: a giant impact ~4 billion years ago Similar to Earth-Moon formation? The planet vote of 2006… and the reaction http://www.iau2006.org Final Resolution 5 for GA-XXVI: Definition of a Planet 24 August 2006 The IAU therefore resolves that planets and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way: (1) A “planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit. (2) A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite. (3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as “Small Solar System Bodies”. Dysnomia …and Ceres are “dwarf planets”? Nix Y Y Y Hydra Eris Y ? ? Historical perspective: how many planets are there? • Antiquity -- 7 planets in geocentric model (Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn) • 1550 – 6 planets in heliocentric model (add Earth, remove Moon and Sun); the reaction was truly Medieval! • 1781 – 7 planets (add Uranus) • 1807 – 11 planets (add Ceres, Pallas, Juno, Vesta) • 1845 – 12 planets (add Astraea) • 1846 – 13 planets (add Neptune) • 1851 – 8 planets (too many objects in Asteroid Belt to include them all – feeling any déjà vu yet?) • 1930 – 9 planets (add Pluto) • 1992 – Discovery of 1992 QB1…the Kuiper Belt! • 2005 – Discovery of Eris (UB313) • 2006 – 8 planets (remove Pluto; don’t add Ceres, Charon, Eris or other “dwarf planets”) Ceres and Pluto: The “ugly duckling” problem of being the first of an entire class Asteroid Belt Kuiper Belt Discovered 1801-1851 Discovered in 1992…or 1930? Ceres Inferring planets from extra-solar Kuiper Belt’s (vice versa): where planetary meets stellar astronomy Ground-based Hubble undithered Hubble dithered High resolution images of Ceres reveal roundness, surface features, and colors Ground-based Hubble undithered Hubble dithered High resolution images of Ceres reveal roundness, surface features, and colors Three different faces of Ceres Three different faces of Ceres Why does roundness matter ? Differentiation of the asteroid Ceres as revealed by its shape Thomas, Parker, McFadden, Russell, Stern, Sykes, Young, 2005, Nature Letters, Vol 437 Annette and Patsy Tombaugh Jim Christy Jim Christy New Horizons launch 19 January 2006 Dawn Ceres 2015 New Horizons Pluto 2015 Vesta 2011 http://www.dawn-mission.org http://pluto.jhuapl.edu A “teachable moment” • Pluto has not changed at all • Classification is an important tool in science; imperfect, but allows us to move forward • Progress is sometimes messy, the truth often seems counterintuitive at first – not determined by a vote • Science is not a static body of facts, it is an ongoing process of discovery and debate I’m delighted when Hubble inspires kids… …because I was inspired