3D Modelling of Near-Earth Asteroids using Lightcurve Database by Jonatan Michimani Garcia Thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN SPACE SCIENCE AND TECHNOLOGY at the Instituto Nacional de Astrof´ısica, Optica´ y Electr´onica February 2019 Tonantzintla, Puebla Under the supervision of: Jos´eRam´on Vald´es Parra, INAOE Jos´eSilviano Guichard Romero, INAOE c INAOE 2019 The author hereby grants to INAOE permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part. Abstract The record of catastrophic impacts of asteroids towards the Earth, indicates that such phenomena will, to a certainty, occur at some time in the future. Given this threat, the only convenient approach to elaborate a mitigation strategy is to know, as much as possible, the characteristics of the objects with high probability of striking the planet: Near-Earth Asteroids (NEAs). This work focuses on the asteroid characteristics that can be obtain through the synthesis of photometric data i.e. period of rotation, amplitude of the lightcurve, shape and direction of the spin axis or pole. The NEAs (25916) 2001 CP44, (1627) Ivar, (1036) Ganymed (1866) Sisyphus and (450894) 2008 BT 18 were selected to be observed during the months of March, April and May. Subsequent, lightcurve analysis was per- formed by means of the software MPO Canopus, and last, with the lightcurves available in the ALCDEF data base and the own data, the inversion method was run in MPO LCInvert software. Accordingly, first it is presented lightcurves of the observed objects as well as period of rotation and amplitude of the lightcurve. Asteroids (25916) 2001 CP44, (1627) Ivar, (1036) Ganymed and (1866) Sisyphus show results that are consistent with others previously published, however as- teroid (450894) 2008 BT 18, due to its binary nature, did now show conclusive results. Shortly it is also presented the outcomes of the inversion process. For as- teroids (25916) 2001 CP44, (1627) Ivar, (1036) Ganymed, the pole direction and shape are close to its true solution, on the other hand, the presented pole and shape of (1866) Sisyphus (450894) 2008 BT 18 are the best fit with the available data and further observations are needed to improve the solution. The results of the characterization process shows that the Schmidt Camera is a suitable instru- ment for asteroid photometry and hence, INAOE should keep on contributing to the effort of NEAs characterization. I II Contents 1 Introduction 1 1.1 Asteroids ............................... 1 1.1.1 DefinitionandMainCharacteristics . 1 1.1.2 OrbitalElements ....................... 4 1.1.3 AsteroidPopulations . 4 1.2 Photometry .............................. 10 2 The Impact Hazard of Near-Earth Asteroids 13 2.1 ARecordofImpacts ......................... 13 2.2 DefendingPlanetEarth . 15 2.2.1 DetectionandTracking. 17 2.2.2 Cataloguing and Orbital Parameters Calculation . .. 19 2.2.3 Mitigation........................... 20 2.2.4 Characterization . 20 2.3 Conclusion............................... 22 3 Objectives and Methodology 23 3.1 Objectives............................... 23 3.2 Methodology ............................. 24 3.2.1 Selection............................ 24 3.2.2 Observations ......................... 27 3.2.3 Photometry .......................... 28 3.2.4 ShapeDetermination . 29 4 Observations, Image Reduction and ALCDEF 31 4.1 Observations.............................. 31 4.1.1 SchmidtCamera ....................... 31 4.1.2 SelectedAsteroidsandImageReduction . 33 4.2 AsteroidLightcurvePhotometryDatabase . 35 5 Results 39 5.1 Lightcurves .............................. 39 5.1.1 (25916)2001CP44 ...................... 40 5.1.2 (1627)Ivar .......................... 46 III IV CONTENTS 5.1.3 (1036)Ganymed ....................... 48 5.1.4 (1866)Sisyphus ........................ 51 5.1.5 (450894)2008BT18. 52 5.2 TheinversionMethod ........................ 55 5.3 MPOLCInvertResults. 58 5.3.1 (25916)2001CP44 ...................... 58 5.3.2 (1627)Ivar .......................... 61 5.3.3 (1036)Ganymed ....................... 65 5.3.4 (1866)Sisyphus ........................ 70 5.3.5 (450894)2008BT18. 73 6 Conclusion and Future Work 77 Bibliography ................................ 79 List of Figures 1.1 From left to right: First picture: Asteroid (25143) Itokawa, vis- ited by the Japanese spacecraft Hayabusa in 2005 and the first one from where material samples were brought to Earth. Credit: NASA/JPL. Second picture: model representation of a radar ob- servation from Asteroid (216) Kleopatra. Credit: Stephen Ostro et al. (JPL), Arecibo Observatory, NSF, NASA . 2 1.2 Geometry of an elliptical orbit in one (a) and three (b) dimensions. The Sun is found at one focus. For solar system objects, the ref- erence plane is the ecliptic (Adapted from Lissauer & de Pater, 2013). ................................. 5 1.3 (a) Histogram of asteroids versus semi-major axis shows primary Kirkwood gaps in the Asteroid Main-Belt (credit: Alan Chamber- lain, JPL/Caltech). (b) Location of Jupiter’s Troyan asteroids at theLagrangianpointsL4andL5(Kutner,2003). 7 1.4 Orbital representation of the different groups of NEAs (Adapted fromJPL,CNEOS).......................... 9 1.5 Lightcurveofasteroid(1627)Ivar.. 11 2.1 (a) Full Moon and (b) Mercury, showing scars of large giant im- pacts that are remnants from the Late Heavy Bombardment pe- riod, about 3.3 billion years ago. Credits: (a) Galileo spacecraft (NASA), (b) University of Arizona/LPL/Southwest Research In- stitute.................................. 14 2.2 Location of inland known craters on the surface of the Earth (Koe- berl,2013). .............................. 15 V VI LIST OF FIGURES 2.3 Examples of impact craters on Earth. (a)Tswaing (Saltpan)-crater in South Africa (1.2 km in diameter, 250,000 years old); (b) Wolfe Creek crater in Australia (1 km in diameter, 1 Ma old); (c) Meteor Crater in Arizona, U.S. (1.2 km in diameter, 50,000 years old); (d) Lonar crater, India (1.8 km in diameter, age ca. 50,000 years); (e) Mistastin crater in Canada (28 km in diameter, age ca. 38 Ma); (f) Roter Kamm crater in Namibia (2.5 km in diameter, age ca. 4 Ma); (g) Clearwater double crater in Canada (24 and 32 in km diameter respectively, age ca. 250 Ma); (h) Gosses Bluff crater in Australia (24 km in diameter, age 143 Ma); and (i) Aorounga crater in Chad (18 km in diameter, younger than ca. 300 Ma), (Koeberl,2013)............................. 16 2.4 (a) Effects on the Siberian forest by the Tunguska asteroid explo- tion, one of the largest recent impacts. Credit: Leonid Kolik. (b) The Chelyabinsk bolide in 2013 renew the awareness of asteroid impacts. Credit: Footageofanamateurvideo. 17 2.5 NEOs current population estimate: Number(N) of objects as a function of absolute magnitud H. Average impact interval scale (right), impact energy released in megatons (MT) of TNT for an assumed velocity of 20 km per second (top), and NEOs diameters determined assuming an average value of albedo of 14% (bottom). (Adapted from Defending Planet Earth, National Research Council). 19 2.6 Number of NEA discoveries per year by Survey. (JPL, Center for NearEarthObjectStudies) . 20 2.7 Cumulative number of known Near-Earth Asteroids versus time. Here is shown the total of NEAs of all sizes discovered by all de- tection surveys differentiating them from the total of NEAs larger than 140 m and larger than 1 km in diameter. Potentially Haz- ardous Asteroids and Near-Earth Comets are also shown. (JPL, CenterfotNearEarthObjectStudies) . 21 3.1 Potential Lightcurve Targets search format from Minor Planet Center.................................. 24 3.2 Example of the associated lightcurves to a certain asteroid, dis- played by the Asteroid Lightcurve Photometry Database site. .. 26 3.3 GraphicenviromentofMPOCanopus. 28 3.4 Graphic interface of the Inversion Wizard from MPO LCInvert. 29 4.1 SchmidtCameraatINAOE. 32 5.1 ..................................... 40 5.2 ..................................... 40 5.3 Field of view around (25916) 2001 CP44 on April 14th, 2018. .. 41 5.4 Field of view around (25916) 2001 CP44 on April 16th, 2018. .. 41 5.5 ..................................... 41 LIST OF FIGURES VII 5.6 ..................................... 41 5.7 ..................................... 42 5.8 ..................................... 42 5.9 Field of view around (25916) 2001 CP44 on April 20th, 2018. .. 43 5.10 Field of view around (25916) 2001 CP44 on April 21st, 2018. ... 43 5.11 ..................................... 43 5.12 ..................................... 43 5.13 ..................................... 44 5.14 ..................................... 44 5.15 Field of view around (25916) 2001 CP44 on May 26th, 2018. .. 45 5.16 Field of view around (25916) 2001 CP44 on May 28th, 2018. .. 45 5.17 ..................................... 45 5.18 ..................................... 45 5.19 ..................................... 46 5.20 ..................................... 46 5.21 Field of view around (1627) Ivar on March 17th, 2018. .. 47 5.22 Field of view around (1627) Ivar on March 27th, 2018. .. 47 5.23 ..................................... 47 5.24 ..................................... 47 5.25 ..................................... 48 5.26 ..................................... 48 5.27 ..................................... 48 5.28 Field of view around (1036) Ganymed on March 19th, 2018. .. 49 5.29 Field of view around (1036) Ganymed on March 20th, 2018.