University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School October 2019 On the Ablation of Meteors and the Implications on Organic Delivery to Earth Christopher Alan Mehta University of South Florida Follow this and additional works at: https://scholarcommons.usf.edu/etd Part of the Geochemistry Commons, and the Geology Commons Scholar Commons Citation Mehta, Christopher Alan, "On the Ablation of Meteors and the Implications on Organic Delivery to Earth" (2019). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/8667 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. On the Ablation of Meteors and the Implications on Organic Delivery to Earth by Christopher Alan Mehta A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy with a concentration in Cosmochemistry School of Geosciences College of Arts and Sciences University of South Florida Major Professor: Matthew Pasek, Ph.D. Aurelie Germa, Ph.D. Jennifer Collins, Ph.D. Laurie Barge, Ph.D. Date of Approval: October 17th, 2019 Keywords: Planetary Geology, Prebiotic Chemistry, Origin of Life. Copyright © 2019, Christopher Alan Mehta DEDICATIONS This dissertation is dedicated to my family. I would not be the person I am today without them. ACKNOWLEDGEMENTS I would like to thank my family Sunil Mehta, Janvi Mehta, Brian Mehta, and Andrea Mehta for their love and support during my educational endeavors. I would especially like to thank my advisor Dr. Matthew Pasek for mentoring me through this process. A special thanks goes to Dr. Aurelie Germa, Dr. Jennifer Collins, Dr. Laurie Barge, and Dr. Maria Womack for helping me on my dissertation and for being on my committee. In addition, I would like to acknowledge Jennifer Lago, Dr. Maheen Gull, Dr. Arthur Omran Tian Feng, Josh Abbatiello, Hanlei Zhang, Carylon Lang, Danny Lindsey, Quinton Vitelli-Hawkins, Kaylie Headings, Anthony Perez, Lori Palaio, Mellyssa Green, Dr. John Dunbar, and Francisco Arreola. I would also like to thank Paul Flaherty, Dr. Brian Belson, Mike Holmes, Jess Williams, Rich Henning, Jack Parrish, Leonard Miller, Akshar Patel, RADM Nancy Hann, Joe Green, Barry Damiano, Ian Sears, and others who worked with me at the National Oceanic and Atmospheric Hurricane Hunters for helping me become a better leader and scientist. Lastly, I would like to thank Monster Energy drink for providing me with the necessary amounts of caffeine to complete this dissertation. Unleash the Beast, indeed. TABLE OF CONTENTS List of Tables .................................................................................................................................. ii List of Figures ................................................................................................................................ iii Abstract .......................................................................................................................................... vi Chapter 1 ..........................................................................................................................................1 1.1 Summary of different types of Meteorites .....................................................................2 1.2 Past Studies ....................................................................................................................3 1.3 Radiometric Dation of Meteorites and Clues to the Early Solar System .......................6 1.4 Organics in Meteoroids, Meteors, and Meteorites .........................................................8 1.5 Meteor Ablation .............................................................................................................9 1.6 Log-Log and Meteor Fragmentation through Ablation .................................................9 Chapter 2. Caveats to Exogenous Organic Delivery from Ablation, Dilution, and Thermal Degradation ..............................................................................................................................13 2.1 Abstract ........................................................................................................................13 2.2 Introduction ..................................................................................................................15 Meteor Energy Loss Due to Ablation ...................................................................15 Thermal Diffusion and Meteor Ablation ...............................................................16 Meteoroid Source Region and Distribution on Impact ..........................................17 2.3 Methodology ................................................................................................................19 Ablation Model ......................................................................................................19 Strewn Field Analysis ............................................................................................22 Thermal Diffusion and Chemical Kinetics Model .................................................22 2.4 Results ..........................................................................................................................23 Strewn Field Analysis Results ...............................................................................24 Radiation Model Results ........................................................................................28 2.5 Discussion ....................................................................................................................28 Calculation of Exogenous Material to The Early Earth .........................................32 2.6 Conclusion ...................................................................................................................32 Chapter 3. The Power-Law and Mass Distributions of Meteoroids and Meteorites .....................34 3.1 Abstract ........................................................................................................................34 3.2 Introduction ..................................................................................................................36 3.3 Methodology ................................................................................................................38 Meteorite Mass-Number Distribution ....................................................................38 Ablation Model ......................................................................................................40 Effect of Physical Variables on Ablation...............................................................41 i 3.4 Results ..........................................................................................................................42 Effects of Varying Angle of Entry, Initial Velocity, and Aspect Ratio .................43 Monte Carlo Simulation .........................................................................................52 3.5 Discussion ....................................................................................................................53 3.6 Conclusion ...................................................................................................................56 Chapter 4. Ablation of Carbonaceous Asteroids and Organic Flux Delivery................................57 4.1 Abstract ........................................................................................................................57 4.2 Introduction ..................................................................................................................58 4.3 Methods........................................................................................................................58 4.4 Results ..........................................................................................................................61 4.5 Discussion ....................................................................................................................63 4.6 Conclusion ...................................................................................................................64 Chapter 5. Concluding Remarks ....................................................................................................66 References ......................................................................................................................................69 ii LIST OF TABLES Table 1.1. Rate of meteor impact of Earth .......................................................................................5 Table 1.2. Summary of common organics found on the Murchison meteorite ....................... 11-12 Table 2.1. Parameters used in ablation model ...............................................................................21 Table 2.2. Minimum initial mass for impact to occur....................................................................26 Table 2.3. Percent of meteors that impact the surface with respect to atmosphere .......................27 Table 3.1. Alpha values calculated using maximum likelihood ....................................................44 Table 3.2. Slope values for finds and falls .....................................................................................44 Table 4.1. Values used