University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects January 2018 Constraining The mS all Binary Asteroid Population Of The ainM Belt Using Doublet Craters On Ceres Paul F. Wren Follow this and additional works at: https://commons.und.edu/theses Recommended Citation Wren, Paul F., "Constraining The mS all Binary Asteroid Population Of The ainM Belt Using Doublet Craters On Ceres" (2018). Theses and Dissertations. 2384. https://commons.und.edu/theses/2384 This Thesis is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. CONSTRAINING THE SMALL BINARY ASTEROID POPULATION OF THE MAIN BELT USING DOUBLET CRATERS ON CERES by Paul Fredrick Wren Bachelor of Science, Arizona State University, 1985 A Thesis Submitted to the Graduate Faculty Of the University of North Dakota In partial fulfillment of the requirements For the degree of Master of Science Grand Forks, North Dakota May 2018 PERMISSION Title Constraining the Small Binary Asteroid Population of the Main Belt Using Doublet Craters on Ceres Department Space Studies Degree Master of Science In presenting this thesis in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the library of this University shall make it freely available for inspection. I further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my thesis work or, in his absence, by the Chairperson of the department or the dean of the School of Graduate Studies. It is understood that any copying or publication or other use of this thesis or part thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any scholarly use which may be made of any material in my thesis. Paul Fredrick Wren May 12, 2018 iii TABLE OF CONTENTS LIST OF FIGURES ………………………………………………………………………….. vii LIST OF TABLES …………………………………………………………………………... viii ACKNOWLEDGEMENTS …………………………………………………………………... ix ABSTRACT ……………………………………………………………………………………. x CHAPTER 1 INTRODUCTION .................................................................................................................. 1 1.1 Motivation ...................................................................................................................................... 1 1.2 State of Research ........................................................................................................................... 2 1.2.1 Doublet Impact Craters ............................................................................................................. 2 1.2.1.1 Observations ..................................................................................................................................... 2 1.2.1.2 Doublet Crater Formation ................................................................................................................. 3 1.2.1.2.1 Tidal fissioning of an incoming impactor ................................................................................. 3 1.2.1.2.2 Tidal Disruption of Contact Binaries Prior to Impact ............................................................... 4 1.2.1.2.3 Tidal Disruption of Rubble Pile and Contact Binary Asteroids ................................................ 5 1.2.2 Binary Asteroids ....................................................................................................................... 5 1.2.2.1 Do Binary Asteroids Exist? .............................................................................................................. 6 1.2.2.2 Discovery .......................................................................................................................................... 7 1.2.2.3 Observations ..................................................................................................................................... 8 1.2.2.3.1 Photometric Observations ......................................................................................................... 8 1.2.2.3.2 Ground-based Direct Imaging ................................................................................................... 9 1.2.2.3.3 Space-based Direct Imaging ...................................................................................................... 9 1.2.2.3.4 Radar Imaging ......................................................................................................................... 10 1.2.2.3.5 Stellar Occultation ................................................................................................................... 10 1.2.2.4 Formation Processes – Main Belt Binaries ..................................................................................... 11 1.2.2.4.1 Rotational Fission .................................................................................................................... 12 1.2.2.4.2 Orbiting Ejecta ......................................................................................................................... 12 1.2.2.4.3 Mutual Capture of Escaping Fragments .................................................................................. 13 1.2.2.4.4 Low Velocity Collision ............................................................................................................ 13 1.2.2.5 Formation Processes – Planet-crossing Binaries ............................................................................ 14 iv 1.2.2.5.1 Tidal Distortion of Planet-crossing Satellites .......................................................................... 14 1.2.2.5.2 Thermal Torque Rotational Fission ......................................................................................... 16 1.2.3 Impact Crater Morphology ..................................................................................................... 19 1.2.3.1 Overview ......................................................................................................................................... 19 1.2.3.2 Oblique Impacts .............................................................................................................................. 20 1.2.3.3 Impact Crater Scaling Laws ............................................................................................................ 22 1.3 Goals and Outline ........................................................................................................................ 24 2 METHODS ............................................................................................................................ 26 2.1 Source Data .................................................................................................................................. 27 2.1.1 Imagery ................................................................................................................................... 27 2.1.2 Elevation Data ........................................................................................................................ 27 2.2 Determining Impactor Size from Craters on Ceres ................................................................. 28 2.2.1 Impact Crater Scaling Laws ................................................................................................... 28 2.2.2 Estimating the Velocity of an Impacting Main Belt Asteroid ................................................ 29 2.2.3 Estimating the Density of an Impacting Main Belt Asteroid ................................................. 30 2.2.4 The Density of Ceres’ Crust ................................................................................................... 30 2.2.5 Crater Scaling Equation for Ceres .......................................................................................... 30 2.3 Impact Crater Survey ................................................................................................................. 31 2.3.1 Survey Area ............................................................................................................................ 31 2.3.2 Identifying and Recording Craters ......................................................................................... 32 2.3.3 Upper Limit for Crater Diameters .......................................................................................... 32 2.3.4 Limitations .............................................................................................................................. 32 2.4 Identifying and Evaluating Potential Doublet Craters ............................................................ 33 2.4.1 Identifying Crater Pairs .......................................................................................................... 33 2.4.2 Evaluating Crater Pairs ........................................................................................................... 34 2.4.3 Limitations .............................................................................................................................. 36 2.5 Monte Carlo Simulation ............................................................................................................