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Killer Asteroids Lab 1
Killer Asteroids Lab #1: Learning how to measure positions and determine orbits GOALS: The goal of this assignment is to learn how to measure asteroid positions in digital images, and how to use these positions to determine the orbit of the asteroid. You will also learn what parameters are necessary to specify an orbit, and the effect of each on the shape and orientation of the orbit. Finally, you will learn how to generate alternate possible orbits for a given asteroid. You will use these skills over the coming weeks to study the asteroid 2007 WD5, which narrowly missed hitting Mars on January 30, 2008. In particular, you will estimate the probability of impact based upon what was known about this object’s orbit at various points between its discovery and the date of the possible impact. You should then understand why every “impact scare” to date has followed the same pattern: Odds first go up, but then they fall quickly to near zero. You’ll also get the “bigger picture”: Science involves uncertainty, and it takes time and hard work to get good results. Part I: Measuring Asteroid Positions with ImageJ The first goal of this assignment is to teach you how to measure the positions of celestial objects in digital images. In particular, you will be measuring the position of an asteroid as it streaks through a field of background stars. (The measurement of positions of celestial objects is known as astrometry.) Of course, since the asteroid is moving, it is also important to accurately note the time at which it was found at a particular position. -
Oca Club Meeting Star Parties Coming Up
February 2008 Free to members, subscriptions $12 for 12 issues Volume 35, Number 2 On January 14, 2008, MESSENGER became the first spacecraft to visit Mercury since Mariner 10 more than 30 years ago. This image shows the hemisphere of Mercury that was not previously imaged by Mariner 10; the Caloris impact basin is visible at upper right. MESSENGER will complete two more flybys of Mercury, in October 2008 and September 2009, before entering orbit around the planet in 2011. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington OCA CLUB MEETING STAR PARTIES COMING UP The free and open club The Black Star Canyon site will be open on The next session of the meeting will be held Friday, February 9th. The Anza site will be open on Beginners Class will be held on February 8th at 7:30 PM in February 2nd. Members are encouraged to Friday, February 1st (our annual the Irvine Lecture Hall of the check the website calendar, for the latest ‘Basics of Astrophotography Hashinger Science Center updates on star parties and other events. class’) at the Centennial at Chapman University in Heritage Museum at 3101 West Orange. The featured Please check the website calendar for the Harvard Street in Santa Ana. speaker this month is Scott outreach events this month! Volunteers GOTO SIG: TBA (contact Kardel of Palomar are always welcome! coordinator for details) Observatory, discussing You are also reminded to check the web Astro-Imagers SIG: Feb. 19th, the 60th anniversary of the site frequently for updates to the calendar Mar. -
Absolute Magnitudes of Asteroids and a Revision of Asteroid Albedo Estimates from WISE Thermal Observations ⇑ Petr Pravec A, , Alan W
Icarus 221 (2012) 365–387 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations ⇑ Petr Pravec a, , Alan W. Harris b, Peter Kušnirák a, Adrián Galád a,c, Kamil Hornoch a a Astronomical Institute, Academy of Sciences of the Czech Republic, Fricˇova 1, CZ-25165 Ondrˇejov, Czech Republic b 4603 Orange Knoll Avenue, La Cañada, CA 91011, USA c Modra Observatory, Department of Astronomy, Physics of the Earth, and Meteorology, FMFI UK, Bratislava SK-84248, Slovakia article info abstract Article history: We obtained estimates of the Johnson V absolute magnitudes (H) and slope parameters (G) for 583 main- Received 27 February 2012 belt and near-Earth asteroids observed at Ondrˇejov and Table Mountain Observatory from 1978 to 2011. Revised 27 July 2012 Uncertainties of the absolute magnitudes in our sample are <0.21 mag, with a median value of 0.10 mag. Accepted 28 July 2012 We compared the H data with absolute magnitude values given in the MPCORB, Pisa AstDyS and JPL Hori- Available online 13 August 2012 zons orbit catalogs. We found that while the catalog absolute magnitudes for large asteroids are relatively good on average, showing only little biases smaller than 0.1 mag, there is a systematic offset of the cat- Keywords: alog values for smaller asteroids that becomes prominent in a range of H greater than 10 and is partic- Asteroids ularly big above H 12. The mean (H H) value is negative, i.e., the catalog H values are Photometry catalog À Infrared observations systematically too bright. -
Near-Earth Objects in the Sloan Digital Sky Survey
Near-Earth Objects in the Sloan Digital Sky Survey S. Kent Nov 27, 2009 Steve Kent, Tom Quinn, Gil Holder, Mark Schaffer, Alex Szalay, Jim Gray, Zeljko Ivezic Outline I. Near-Earth Objects II. Brief Description of SDSS imaging survey III. NEO population IV. NEO Composition and origin Particle to Astro Translation Guide Particle Physics Term Astrophysics Term Beam Line Telescope Monte Carlo Simulation Calorimetry Photometry Energy histogram Spectrum Pedestal Bias Trigger table Target Selection Algorithm Tracking Astrometry Silicon Pixel Detector Silicon Pixel Detector Charged particle track Signal Noise I. NEO Basic Information 1. Definition: NEO = Near Earth Object (asteroid or comet). Perihelion q < 1.3 AU. ~7000 known. 2. PHA = Potentially Hazardous Asteroid ( big & might hit the earth). 997 Known H=13 10 km diam - Dinosaur extinction H=18 1 km diam - Goal for completeness (H is apparent mag of asteroid viewed face-on from sun at a distance of 1 AU) Distribution of Main Belt Asteroids Orbits of NEO's Typical NEA Orbit Programs to find NEOs 1. LINEAR (Lincoln Near Earth Asteroid Research) MIT/Lincoln Lab Telescope near Socorro, NM 2. NEAT ( Near Earth Asteroid Tracking) JPL Telescopes in Hawaii / Palomar (CA) 3. LONEOS (Lowell Observatory) Lowell, AZ 4. Spacewatch (Steward Observatory) Kitt Peak 5. Catalina Sky Survey Steward Observatory; ANU 3 telescopes (Catalina Mtns; Siding Springs) SpaceGuard - Goal is to find 90% of all NEAs D > 1 km (H~18) Aside ... The “measure” of a NEO ● Absolute Magnitude H ● Diameter D ● Mass M ● Energy E (Megatons) ● Crater diameter ● Inter-relationships depend on – Density – Albedo – Impact target (Moon v. -
Planète 1 Planète
Planète 1 Planète Une planète est un corps céleste orbitant autour du Soleil ou d'une autre étoile de l'Univers et possédant une masse suffisante pour que sa gravité la maintienne en équilibre hydrostatique, c'est-à-dire sous une forme presque sphérique. La définition scientifique rigoureuse, d'une part veut qu'on réserve le nom de « planète » aux objets du système solaire (dans les autres cas, on parle d'exoplanètes), d'autre part exige que ce corps céleste ait éliminé tout corps rival se déplaçant sur une orbite proche (cela peut signifier soit en faire un de ses satellites, soit provoquer sa destruction par collision). Ce dernier critère ne s'applique pas aux exoplanètes[1] . On estime que le nombre de planètes dans notre seule galaxie est de 1000 milliards[2] . Selon cette définition (qui fut approuvée le 24 août 2006 en clôture de la 26e Assemblée Générale de l'Union astronomique internationale (UAI) huit planètes ont été recensées dans le système solaire : Mercure, Vénus, la Terre, Mars, Jupiter, Saturne, Uranus et Neptune (les quatre premières étant des planètes telluriques alors que les quatre suivantes sont des géantes gazeuses). En même temps que la définition d'une planète était clarifiée, l'UAI définissait comme étant une planète naine un objet céleste répondant à tous les critères, sauf l'élimination des corps sur une orbite proche. Contrairement à ce que suggère l'usage habituel d'un adjectif, une planète naine n'est pas une planète. On compte actuellement cinq planètes naines dans le système solaire : Cérès, Pluton, Makemake, Haumea et Éris[3] . -
Planetary Defense: an Overview
Planetary Defense: An Overview William Ailor, Ph.D. The Aerospace Corporation September 2011 © The Aerospace Corporation 2011 Background • Considerable work over the last several years on understanding the threat, proposing actions • 2004, 2007, 2009, 2011 Planetary Defense Conferences discussed – What we know about the threat to Earth from asteroids and comets – Consequences of impact – Techniques for deflection and disruption – Deflection mission design – Disaster mitigation – Political, policy, legal issues associated with mounting a deflection mission – Details and videos at www.planetarydefense.info, www.pdc2011.org • Highlights from 2011 IAA Planetary Defense Conference presented later in this briefing The Threat © The Aerospace Corporation 2011 Larger Meteor Events • 10 to 20 meteor impact events occur worldwide each day • 2 to 5 events/ day with potential for discovery by people • Injury has occurred, but rare October 9, 1992 March 27, 2003: Chicago (Park Forrest) • 27 March 2003, 05:50 UT (12:50 AM local time) Credit: Sgt. Kile - South Haven Indiana Police Department Prof. Peter Brown - University of Western Ontario • Southern suburbs of Chicago Dr. Dee Pack - The Aerospace Corporation • Camera in stationary squad car parked about 150 km away Video courtesy of University of Western Ontario, South Haven Indiana • Five structures damaged Police Department, and The Aerospace Corporation • Object estimated to be ~2 m in diameter, weigh ~7 tons Chicago (Park Forest) Impact, March 27, 2003 • Video image courtesy of ABC News, Channel 7, Chicago, IL. 6 Events June 30, 1908: Tunguska, Siberia • Airburst of ~30 m diameter object at ~6 km altitude 1.2 kilometer BARRINGER (OR METEOR) CRATER, Arizona, • 2-15 MT explosion was created about 49,000 years ago by a small nickel-iron asteroid (Photo by D.J. -
Planets Solar System Paper Contents
Planets Solar system paper Contents 1 Jupiter 1 1.1 Structure ............................................... 1 1.1.1 Composition ......................................... 1 1.1.2 Mass and size ......................................... 2 1.1.3 Internal structure ....................................... 2 1.2 Atmosphere .............................................. 3 1.2.1 Cloud layers ......................................... 3 1.2.2 Great Red Spot and other vortices .............................. 4 1.3 Planetary rings ............................................ 4 1.4 Magnetosphere ............................................ 5 1.5 Orbit and rotation ........................................... 5 1.6 Observation .............................................. 6 1.7 Research and exploration ....................................... 6 1.7.1 Pre-telescopic research .................................... 6 1.7.2 Ground-based telescope research ............................... 7 1.7.3 Radiotelescope research ................................... 8 1.7.4 Exploration with space probes ................................ 8 1.8 Moons ................................................. 9 1.8.1 Galilean moons ........................................ 10 1.8.2 Classification of moons .................................... 10 1.9 Interaction with the Solar System ................................... 10 1.9.1 Impacts ............................................ 11 1.10 Possibility of life ........................................... 12 1.11 Mythology ............................................. -
Exploring the Deflection of Potentially Hazardous Objects by Stand-Off Bursts
Lunar and Planetary Science XXXIX (2008) 2311.pdf EXPLORING THE DEFLECTION OF POTENTIALLY HAZARDOUS OBJECTS BY STAND-OFF BURSTS. C. S. Plesko1,2, J. A. Guzik2, R. F. Coker2, W. F. Huebner3, J. J. Keady4, R. P. Weaver2, and L. A. Pritchett-Sheats5 1U. C. Santa Cruz, [email protected], 2Applied Physics Division, LANL, 3Southwest Research Institute 4Atomic and Optical Theory Group, LANL, 5High Performance Computing Division, LANL. * Introduction: The recent discovery of Asteroid likely internal configurations, and constrains QS , the 2007 WD5’s close approach to Mars [1] is a reminder energy required to shatter the body, an upper safety that asteroid impacts are a rare but inevitable occur- limit for stand-off bursts [10]. rence, and that potentially hazardous objects (PHOs) The RAGE Hydrocode. The Radiation Adaptive cannot always be discovered well in advance of a close Grid Eulerian (RAGE) code is a version of the SAIC approach. The prevention of impacts on Earth is a sub- Adaptive Grid Eulerian (SAGE) hydrocode with radia- ject of varied research and debate. The only methods tive transfer enabled [12]. Simulations may be carried of impact prevention currently available are deflection out in multiple dimensions, a variety of geometries, or disruption and dispersal by nuclear or chemical ex- and with an arbitrary number of constitutive materials plosion or a kinetic impactor. The best method to use via the LANL SESAME database [13]. Elastic-Plastic depends on the individual scenario; mainly the time to and Tepla strength models, and a P-alpha crush model impact, and the composition and trajectory of the PHO. -
January 2008
January 2008 The Warren Astronomical Society Paper P.O. Box 1505 Warren, Michigan 48090-1505 www.warrenastronomicalsociety.org Volume 40, Number 1__ // 2008 WAS OFFICERS \\ January, 2008_____ President - - - - Bob Berta 1 st VP - - - - - - - Gary Ross 2nd VP - - - - - - - - Marty Kunz Treasurer - - - Stephen Uitti Secretary - - - - - John Kade Publications - - - - Larry Phipps Outreach Chariman - - - - John Kriegel The WASP (Warren Astronomical Society Paper) is the official monthly publication of the Society. Each new issue of the WASP is e-mailed to each member and/or available online www.warrenastronomicalsociety.org. Requests by other Astronomy clubs to receive the WASP, and all other correspondence should be addressed to the editor, Cliff Jones, email: [email protected] Articles for inclusion in the WASP are strongly encouraged and should be submitted to the editor on or before the first of each month. Any format of submission is accepted, however the easiest forms for this editor to use are plain text files. Most popular graphics formats are acceptable. Materials can be submitted either in printed form in person or via US Mail, or preferably, electronically via direct modem connection or email to the editor. Disclaimer: The articles presented herein represent the opinions of the authors and are not necessarily the opinions of the WAS or the editor. The WASP reserves he right to deny publication of any submission. goodies provided and the warm hellos, as we Astro Chatter entered the Gathen library. by Larry Kalinowski More award badges were given out to members The best meeting of the year at the banquet. Mike Simonsen got his badge occurred at DeCarlo’s last month. -
UCLA Electronic Theses and Dissertations
UCLA UCLA Electronic Theses and Dissertations Title Solar Radiation and Near-Earth Asteroids: Thermophysical Modeling and New Measurements of the Yarkovsky Effect Permalink https://escholarship.org/uc/item/7cw4r38w Author Nugent, Carolyn Rosemary Publication Date 2013 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California University of California Los Angeles Solar Radiation and Near-Earth Asteroids: Thermophysical Modeling and New Measurements of the Yarkovsky Effect A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Geophysics and Space Physics by Carolyn Rosemary Nugent 2013 c Copyright by Carolyn Rosemary Nugent 2013 Abstract of the Dissertation Solar Radiation and Near-Earth Asteroids: Thermophysical Modeling and New Measurements of the Yarkovsky Effect by Carolyn Rosemary Nugent Doctor of Philosophy in Geophysics and Space Physics University of California, Los Angeles, 2013 Professor Jean-Luc Margot, Chair This dissertation examines the influence of solar radiation on near-Earth asteroids (NEAs); it investigates thermal properties and examines changes to orbits caused by the process of anisotropic re-radiation of sunlight called the Yarkovsky effect. For the first portion of this dissertation, we used geometric albedos (pV ) and diameters derived from the Wide-Field Infrared Survey Explorer (WISE), as well as geometric albedos and diameters from the literature, to produce more accurate diurnal Yarkovsky drift predic- tions for 540 NEAs out of the current sample of ∼ 8800 known objects. These predictions are intended to assist observers, and should enable future Yarkovsky detections. The second portion of this dissertation introduces a new method for detecting the Yarkovsky drift. -
International Astronomical Union Union Astronomique Internationale Dr
International Astronomical Union Union Astronomique Internationale Dr. Karel A. van der Hucht, General Secretary 98bis Bd Arago, F – 75014 Paris, France Phone: +33 1 43 258 358 – Fax: +33 1 43 252 616 Email: [email protected] – URL: http://www.iau.org/ Paris, 29 October 2008 To: Dr. Niklas Hedman, Chief Committee Services and Research Section United Nations Office for Outer Space Affairs United Nations Office at Vienna, Wagramerstrasse 5 A-1400 VIENNA Austria your reference: OOSA/2008/06, CU 2008/91 (B) Dear Dr. Niklas Hedman, In response to your request of 7 August 2008 to the IAU to submit information on its Near-Earth Object activities for consideration by the Science Technical subcommittee of the UN committee for the Peaceful uses of Outer space (UN-COPUOS) in its forthcoming meeting, February 2009, please accept the report given below. ******** I . The Minor Planet Center by Dr. Timothy B. Spahr, Director Minor Planet Center (MPC) HCO/SAO Harvard Smithsonian Center for Astrophysics MS 18 60 Garden Street Cambridge, MA 02138-1516 USA <[email protected]> The Minor Planet Center (MPC) is operated at the Smithsonian Astrophysical Observatory (SAO) in Cambridge (MA, USA), and supported by the IAU. The MPC is responsible for collection, validation, and distribution of all positional measurements made world wide of minor planets, comets and outer irregular natural satellites. While the MPC handles data on all classes of object it focuses on the rapid collection and distribution of observations and orbits of Near-Earth Objects (NEOs). The MPC's pipeline for processing NEO data is as follows: NEO data from observers worldwide is sent to the MPC either via e-mail or via ftp. -
Detection of Semimajor Axis Drifts in 54 Near-Earth Asteroids: New Measurements of the Yarkovsky Effect
The Astronomical Journal, 144:60 (13pp), 2012 August doi:10.1088/0004-6256/144/2/60 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. DETECTION OF SEMIMAJOR AXIS DRIFTS IN 54 NEAR-EARTH ASTEROIDS: NEW MEASUREMENTS OF THE YARKOVSKY EFFECT C. R. Nugent1, J. L. Margot1,2,S.R.Chesley3, and D. Vokrouhlicky´ 4 1 Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095, USA 2 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA 3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA 4 Institute of Astronomy, Charles University, V Holesovi˘ ck˘ ach´ 2, CZ-18000 Prague 8, Czech Republic Received 2012 April 16; accepted 2012 June 7; published 2012 July 12 ABSTRACT We have identified and quantified semimajor axis drifts in near-Earth asteroids (NEAs) by performing orbital fits to optical and radar astrometry of all numbered NEAs. We focus on a subset of 54 NEAs that exhibit some of the most reliable and strongest drift rates. Our selection criteria include a Yarkovsky sensitivity metric that quantifies the detectability of semimajor axis drift in any given data set, a signal-to-noise metric, and orbital coverage requirements. In 42 cases, the observed drifts (∼10−3 AU Myr−1) agree well with numerical estimates of Yarkovsky drifts. This agreement suggests that the Yarkovsky effect is the dominant non-gravitational process affecting these orbits, and allows us to derive constraints on asteroid physical properties. In 12 cases, the drifts exceed nominal Yarkovsky predictions, which could be due to inaccuracies in our knowledge of physical properties, faulty astrometry, or modeling errors.