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University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies Legacy Theses 2010 Physical Properties of Fireball-Producing Earth-Impacting Meteoroids and Orbit Determination through Shadow Calibration of the Buzzard Coulee Meteorite Fall Milley, Ellen Palesa Milley, E. P. (2010). Physical Properties of Fireball-Producing Earth-Impacting Meteoroids and Orbit Determination through Shadow Calibration of the Buzzard Coulee Meteorite Fall (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/17766 http://hdl.handle.net/1880/47937 master thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY Physical Properties of Fireball-Producing Earth-Impacting Meteoroids and Orbit Determination through Shadow Calibration of the Buzzard Coulee Meteorite Fall by Ellen Palesa Milley A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF GEOSCIENCE CALGARY, ALBERTA April, 2010 ©c Ellen Palesa Milley 2010 The author of this thesis has granted the University of Calgary a non-exclusive license to reproduce and distribute copies of this thesis to users of the University of Calgary Archives. Copyright remains with the author. Theses and dissertations available in the University of Calgary Institutional Repository are solely for the purpose of private study and research. They may not be copied or reproduced, except as permitted by copyright laws, without written authority of the copyright owner. Any commercial use or re-publication is strictly prohibited. The original Partial Copyright License attesting to these terms and signed by the author of this thesis may be found in the original print version of the thesis, held by the University of Calgary Archives. Please contact the University of Calgary Archives for further information: E-mail: [email protected] Telephone: (403) 220-7271 Website: http://archives.ucalgary.ca Abstract The physical properties of the meteoroid population were investigated through combining data from a number of fireball camera networks. PE values, as a measure of meteoroid strength, were calculated and linked with other observational criteria (Tisserand param eter, meteor shower identification). The historic divisions for fireball types based on the PE criterion were not observed in the large data set, but a correlation with source re gion was recognized. Meteor showers demonstrated different amounts of variation in PE values potentially related to the materials found in each parent comet. The trajectory and pre-fall orbit for the Buzzard Coulee meteoroid were determined through the calibration of shadows cast by the fireball. The method of using shadows to triangulate a trajectory was developed and evaluated. The best fit trajectory was coupled with an initial velocity of 18.0 km/s to compute the heliocentric orbit. Buzzard Coulee fell from a modestly inclined near-Earth Apollo orbit. It is the 12th fallen meteorite to be associated with an orbit. ii Acknowledgements First and foremost I would like to thank Dr. Alan Hildebrand for his experience, guidance and financial support throughout the course of this project. He has given me an incredible number of learning opportunities from the classroom in Geology 699: Meteorites and Asteroids, to travelling the world and meeting other scientists in Prague, Czech Republic. He has been pivotal in the progress of my research project, has extended me invitations for speaking engagements, given me experience working with the media and allowed me to lead some of the meteorite search efforts. It has been an adventure. I am grateful to Dr. Margaret Campbell-Brown for her time and patience working with me throughout the past years. She has provided me with continuous support and supervision throughout my project. She was a wonderful host during my two visits to the University of Western Ontario. I would like to acknowledge Dr. Peter Brown for his time and consistent support throughout my project. In particular, I would like to thank him for the work he did in calibrating Gordon Sarty’s all-sky camera to work out an initial velocity for Buzzard Coulee, and in adapting code and running numerous simulations to determine the un certainties in the trajectory solution. Your knowledge in meteor science is an immense resource, thank you for sharing it with me. Thank you to my examination committee members for taking the time out of their busy schedules to read and review my work. Additionally I would like to thank a number of people for their contributions and guidance. In the Meteor Physics Group at the Uni versity of Western Ontario: Dr. Wayne Edwards, Sean Kohut and Zbigniew Krzeminski. At Portland State University: Drs. Alex Ruzicka and Melinda Hutson. Thanks to Mike Noble for the effort in taking crucial measurements for the site surveys at camera loca tions. Rob Cardinal for computer assistance, creating orbit plots and predicting Buzzard iii iv Coulee’s position prior to falling. Jeff Kriz, for driving long hours and staying up late to help take pictures of stars. A special thank you to Lynne Maillet for her computer software assistance, her expertise in mapping and for lending me her camera to take stellar shots. There are hundreds of people who have had an influence over my project, many may not even realize it. Thank you to the landowners, search volunteers, business owners and camera operators in Buzzard Coulee and beyond. I would like to extend my gratitude to video owners for kindly granting me the use of their records: Adam Baxter and the town of Devon, Glenn Lypkie, Alister Ling, Rod and Diana Meger, Ali and Fara Rahmanian, Gordon Sarty, and Rob Tait. Thank you to the landowners, in particular to Al and Jan Mitchell, Ellen and Ian Mitchell, Barb and Elwood Ferguson, for allowing us to trample through their fields in the name of science. A special thank you to Ellen and Ian for their gracious hospitality in hosting our search headquarters and for giving me two rocks that hold a special place in my heart. I am grateful to a number of funding institutions for their support throughout my graduate work: NSERC for a Canada Graduate Scholarship, Alberta Ingenuity Fund for an Incentive Award, the Department of Graduate Studies for two Graduate Research Scholarships, the Canadian Space Agency for a Space Awareness & Learning Grant and to the Graduate Student Association (University of Calgary) for a Conference Grant. Friends and family often seem to be left until the end of the acknowledgements, of course without them I would not be where I am today. Samantha Jones, thank you for showing me how it is all done, you are a role model and a great friend. Thank you to my family for their unwavering support. Bobby, your continuity in my life is a foundation, thank you for your patience. “Equipped with his five senses, man explores the universe around him and calls the adventure Science.” — Edwin Hubble, 1889-1953 For my Family. v vi Table of Contents Abstract ....................................... ii Acknowledgements ................................. iii Table of Contents .................................. vi List of Tables .................................... vii List of Figures .................................... viii List of Units and Symbols ............................. ix List of Acronyms and Abbreviations ....................... xi 1 Introduction .................................. 1 1.1 Comets, Asteroids and Meteors ....................... 1 1.2 Linking Origin and Material ......................... 7 1.2.1 The PE Criterion ........................... 7 1.2.2 The Tisserand Parameter ...................... 9 1.2.3 Meteorites Associated with an Orbit . 9 1.3 The Buzzard Coulee Fall ........................... 15 1.4 Research Project Outline ........................... 15 2 Fireball Network Events ........................... 17 2.1 Historical Overview of Fireball Networks . 17 2.2 Methodology ................................. 21 2.2.1 Calibration, Trajectory and Orbit Derivation . 21 2.2.2 Determining Mass and Calculating the PE Criterion . 23 2.2.3 Combining and Correcting Data from Fireball Networks . 27 2.3 Results and Discussion ............................ 30 2.3.1 PE Value Distributions by Fireball Network . 30 2.3.2 Fireball Strength and Source Region . 34 2.3.3 PE Values of Shower Events ..................... 38 2.3.4 Distribution of Orbital Elements . 41 2.4 Summary and Conclusions .......................... 48 3 The Buzzard Coulee Meteorite Fall ..................... 51 3.1 Introduction to the Buzzard Coulee Event . 51 3.1.1 Naming and Typing of the Meteorite . 54 3.2 Atmospheric Trajectory ........................... 60 3.2.1 Shadow Calibrations ......................... 60 3.2.2 Video Calibrations .......................... 70 3.2.3 Trajectory Results and Discussion . 74 3.2.4 Velocity Results and Discussion ................... 84 3.3 Pre-Fall Orbit ................................. 89 3.3.1 Discussion ............................... 89 3.4 Summary and Conclusions .......................... 99 Bibliography .................................... 102 A Fireball Networks ..............................