Mars on Earth Discovery and Characterization Cover Images Top: The Hyper-arid, Mars Analog, Atacama Desert (Chile) with color modifications to appear like a surface image from Mars. Modifications were made with Photoshop by Jacek Weirzchos. Photo Credit: Jacek Weirzchos. Bottom: The surface of Mars. Photo Credit: NASA/JPL. Mars on Earth: Discovery and Characterization Methods and technologies to advance the search for Martian sub-surface life. First Year Report (In Partial Fulfillment of D.Phil Requirements) Lauren E. Fletcher Atmospheric, Oceanic, and Planetary Physics University of Oxford Oriel College Supervisors: Dr. Neil E. Bowles and Dr. Charles Cockell (University of Edinburgh) Word Count: 15,076 (main text) August 31, 2011 i Fletcher Year 1 Report Rev: Final Mars on Earth: Discovery and Characterization Methods and technologies to advance the search for Martian sub-surface life. Lauren E. Fletcher Oriel College, University of Oxford First Year Report (In Partial Fulfillment of D.Phil Requirements) Abstract The motivation for this project is to try to answer some of mankind‟s most important questions: “Where did we come from?”, “Are we alone in the universe?”, and “What is our future beyond the Earth?” The sub-surface environments of Mars are some of the best places to try to find answers these questions, with the first step to determine if any one location is habitable (or simply that it provides the necessary conditions and resources to support life). A systematic approach to the quantification of the habitability of subsurface environments on Mars is proposed. This will include a series of sensors integrated into a bore-hole device which could be used as part of future drilling missions to Mars. The work presented in this report starts with a brief overview of previous missions including scientific results relevant to the sub-surface environments of this project and what is missing from these previous missions as well as upcoming missions. This is followed by a discussion of the history of the exploration of Mars prior to the modern space age which provides the fundamental motivation for this project and ends with the establishment of the central hypothesis of the project: The subsurface environment of Mars provides habitable conditions sufficient to support life. Definitions of the fundamental concepts of Life and Habitable are provided that are used to develop a list of questions that must be answered in order to quantify a habitable environment on Mars and includes suggested specific measurements for this purpose. The concept of testing all instruments with analog materials and in simulated and natural Martian analog environments is presented with the selection, collection, and initial characterization of analog materials. Results from the testing of two Relative Humidity (RH) and two RTD temperature sensors are also presented. The final section provides an outline of the proposed dissertation and the work necessary to complete each of the chapters. i ii Fletcher Year 1 Report Rev: Final Table of Contents Acknowledgements .................................................................................................................... 1 1. Introduction ........................................................................................................................ 3 2. Development of Hypothesis and Questions to Answer on the Habitability of Mars ......... 5 2.1. An historical perspective on the exploration and search for life on Mars prior to the modern space age ................................................................................................................... 5 2.2. “Life”: The continuing saga of a 2500 year old debate............................................... 8 2.3. Defining Habitable ...................................................................................................... 9 2.4. Habitability of Mars: Background, Measurements and Questions ........................... 14 2.4.1. The Exploration and Search for Life on Mars in the Modern Space Age ......... 14 2.4.2. Principle Characteristics of the Planet Mars ...................................................... 14 2.4.3. Water and Energy: Central Strategies to Finding Habitable Environments ...... 16 2.4.3.1. Follow the Water ........................................................................................ 17 2.4.3.2. Follow the Energy ...................................................................................... 17 2.4.4. Raw Materials .................................................................................................... 19 2.4.5. Looking for Life Directly................................................................................... 20 2.4.6. Habitability of Mars: Measurements ................................................................. 20 2.4.7. Questions to Quantify the Habitability of Sub-Surface Mars ............................ 21 3. Terrestrial Materials and Simulated and Natural Environments as Analogs for Mars Research ................................................................................................................................... 22 3.1. What are Analogs, how are they qualified, and how can they be used? ................... 22 3.2. Materials .................................................................................................................... 23 3.3. Simulated Environments ........................................................................................... 24 3.4. Natural Environments ............................................................................................... 25 4. Analog Materials Selection, Collection, and Characterization ........................................ 26 4.1. Analog Material Selection ......................................................................................... 26 4.2. Field Expeditions for Collection of Analog Materials .............................................. 28 4.2.1. Mojave Desert .................................................................................................... 28 4.2.2. Panoche Hills ..................................................................................................... 28 4.2.3. Atacama Desert, Chile ....................................................................................... 29 4.2.4. Atlas Mountains, Eastern Morocco.................................................................... 30 4.2.4.1. Travertines .................................................................................................. 31 4.2.4.2. Carbonates .................................................................................................. 31 4.2.4.3. Stromatolite ................................................................................................ 31 4.2.4.4. Basalt .......................................................................................................... 32 4.2.5. Rio Tinto, Spain ................................................................................................. 32 iii Fletcher Year 1 Report Rev: Final 4.3. Analog Material Characterization ............................................................................. 33 4.3.1. Methods.............................................................................................................. 33 4.3.1.1. Preparation of Samples ............................................................................... 33 4.3.1.2. IR Diffuse Reflectance Characterization .................................................... 34 4.3.2. Results and Discussion ...................................................................................... 35 5. Sensor Development Testing ........................................................................................... 37 5.1. Parameters and Ranges.............................................................................................. 37 5.2. Temperature Testing ................................................................................................. 38 5.3. Relative Humidity Testing ........................................................................................ 38 5.4. Calibration of RH Sensors......................................................................................... 41 6. Forward Work Plan .......................................................................................................... 43 References: ............................................................................................................................... 47 Appendix A: Table of Material Analogs ................................................................................. 56 Appendix B: List of Other Analogs in Figures 4-1 & 4-2 ....................................................... 57 iv Fletcher Year 1 Report Rev: Final Acknowledgements The development of any project relies on the help of many people. I gratefully would like to thank the following people for their generous time, comments, and support. Dr. Gian Gabriele Ori for organizing the Field Expeditions to Morocco and the Rio Tinto and the many great field researchers on these trips who helped in the identification and selection of the analog materials collected for this project. Dr. Julio Valdivia and Saul Perez-Montano who have been steadfast collaborators and friends over the past several years in Peru whose contributions to this project are too numerous to list. Dr. Charles Cockell whose insights into Astrobiology field work are central