2014 Annual Science Report
Rensselaer Polytechnic Institute Reporting | SEP 2013 – DEC 2014
Executive Summary
Introduction
Our investigators are members of the New York Center for Astrobiology (NYCA; www.origins.rpi.edu), based at Rensselaer Polytechnic Institute (RPI) in partnership with Syracuse University, the University at Albany, the University of Arizona, and Albion College. Our research is devoted to elucidating the origins of both life itself and of habitable planetary environments, in our own Solar System and in planet-forming regions around other stars: in short, to develop realistic, widely applicable models for the emergence of molecular complexity leading to life. This is being accomplished through a synergy of interdisciplinary research that unifies astronomical observations, laboratory experiments and computational modeling. It addresses several goals of the Astrobiology Roadmap, including Goal 1 (potential for habitable planets), Goal 2 (life in our Solar System), Goal 3 (origins of life), Goal 4 (Earth’s early biosphere and environment), and Goal 7 (signatures of life ... Continue reading.
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Douglas Whittet
NAI, ASTEP, ASTID, Exobiology -
TEAM Active Dates:
2/2009 - 1/2015 CAN 5 -
Team Website:
http://www.origins.rpi.edu -
Members:
28 (See All) - Visit Team Page
Project Reports
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Project 6: Prebiotic Chemical Catalysis on Early Earth and Mars
The “RNA World” hypothesis is the current paradigm for the origins of terrestrial life. Our research is aimed at testing a key component of this paradigm: the efficiency with which RNA molecules form and grow under realistic conditions. We are studying abiotic production and polymerization of RNA by catalysis on montmorillonite clays. The catalytic efficiency of different montmorillonites are determined and compared, with the goal of determining which properties distinguish good catalysts from poor catalysts. We are also investigating the origin of montmorillonites, to test their probable availability on the early Earth and Mars, and the nature of catalytic activity that could have led to chiral selectivity on Earth.
ROADMAP OBJECTIVES: 3.1 3.2 -
Project 5: The Environment of the Early Earth
This project involves the development of capabilities that will allow scientists to obtain information about the conditions on early Earth (3.0 to 4.5 billion years ago) by performing chemical analyzes of crystals (minerals) that have survived since that time. When they grow, minerals incorporate trace concentrations of ions and gaseous molecules from the local environment. We are conducting experiments to calibrate the uptake of these “impurities” that we expect to serve as indicators of temperature, moisture, oxidation state and atmosphere composition. To date, our focus has been mainly on zircon (ZrSiO4), but we have recently turned our attention to quartz as well.
ROADMAP OBJECTIVES: 1.1 4.1 -
Project 2: Processing of Precometary Ices in the Early Solar System
The discovery of numerous planetary systems still in the process of formation gives us a unique opportunity to glimpse how our own solar system may have formed 4.6 billion years ago. Our goal is to test the hypothesis that the building blocks of life were synthesized in space and delivered to the early Earth by comets and asteroids. We use computers to simulate shock waves and other processes that energize the gas and dust in proto-planetary disks and drive physical and chemical processes that would not otherwise occur. Our work seeks specifically to determine (i) whether asteroids and comets were heated to temperatures that favor prebiotic chemistry; and (ii) whether the requisite heating mechanisms operate in other planetary systems forming today.
ROADMAP OBJECTIVES: 1.1 3.1 3.2 -
Project 7: Microenvironmental Influences on Prebiotic Synthesis
Before biotic, i.e., “biologically-derived” pathways for the formation of essential biological molecules such as RNA, DNA and proteins could commence, abiotic pathways were needed to form the molecules that were the basis for the earliest life. Much research has been done on possible non-biological routes to synthesis of RNA, thought by many to be the best candidate or model for the emergence of life. Our work focuses on possible physicochemical microenvironments and processes on early earth that could have influenced and even directed or templated the formation of RNA or its predecessors.
ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 -
Project 1: Interstellar Origins of Preplanetary Matter
Interstellar space is rich in the raw materials required to build planets and life, including essential chemical elements (H, C, N, O, Mg, Si, Fe, etc.) and compounds (water, organic molecules, planet-building minerals). This research project seeks to characterize the composition and structure of these materials and the chemical pathways by which they form and evolve. The long-term goal is to determine the inventories of proto-planetary disks around young sun-like stars, leading to a clear understanding of the processes that led to our own origins and insight into the probability of life-supporting environments emerging around other stars.
ROADMAP OBJECTIVES: 1.1 3.1 -
Project 3: Impact History of the Earth-Moon System
The influx of interplanetary debris onto the early Earth represents a major hazard to the emergence of life. Large crater-forming bodies must have been common in the early solar system, as craters are seen on all ancient solid surfaces from Mercury to the moons of the outer planets. Impact craters are few in number on the Earth today only because geologic activity and erosion gradually erase them. The Earth’s nearest neighbor, the Moon, lacks an atmosphere and significant tectonic activity, and therefore retains a record of past impacts. The goal of our research is to reconstruct the bombardment history of the Moon, and by proxy the Earth, to establish when the flux of sterilizing impacts declined sufficiently for the Earth to became habitable.
ROADMAP OBJECTIVES: 4.3 -
Project 4: Vistas of Early Mars: In Preparation for Sample Return
To understand the history of life in the solar system requires knowledge of how hydrous minerals form on planetary surfaces, and the role minerals may play in the development of potential life forms. The minerals hematite and jarosite have been identified on Mars and presented as in situ evidence for aqueous activity. This project seeks to understand (i) the conditions required for jarosite and hematite formation and preservation on planetary surfaces, and (ii) the conditions under which their “radiometric clocks” can be reset (e.g., during changes in environmental conditions such as temperature). By investigating the kinetics of noble gases in minerals, known to occur on Mars and Earth, we will be prepared to analyze and properly interpret ages measured on samples from future Mars sample return missions.
ROADMAP OBJECTIVES: 2.1 3.1 7.1
Publications
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Aldersley, M. F., & Joshi, P. C. (2013). RNA dimer synthesis using montmorillonite as a catalyst: The role of surface layer charge. Applied Clay Science, 83-84, 77–82. doi:10.1016/j.clay.2013.08.009
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Aldersley, M. F., & Joshi, P. C. (2014). The Role of Fluoride in Montmorillonite-Catalyzed RNA Synthesis. Journal of Molecular Evolution, 78(5), 275–278. doi:10.1007/s00239-014-9619-y
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Aldersley, M. F., Joshi, P. C., Schwartz, H. M., & Kirby, A. J. (2014). The reaction of activated RNA species with aqueous fluoride ion: a convenient synthesis of nucleotide 5′-phosphorofluoridates and a note on the mechanism. Tetrahedron Letters, 55(8), 1464–1466. doi:10.1016/j.tetlet.2014.01.051
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Cassidy, L. M., Burcar, B. T., Stevens, W., Moriarty, E. M., & McGown, L. B. (2014). Guanine-Centric Self-Assembly of Nucleotides in Water: An Important Consideration in Prebiotic Chemistry. Astrobiology, 14(10), 876–886. doi:10.1089/ast.2014.1155
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De Hoog, J. C. M., Lissenberg, C. J., Brooker, R. A., Hinton, R., Trail, D., & Hellebrand, E. (2014). Hydrogen incorporation and charge balance in natural zircon. Geochimica et Cosmochimica Acta, 141, 472–486. doi:10.1016/j.gca.2014.06.033
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Gombosi, D. J., Baldwin, S. L., Watson, E. B., Swindle, T. D., Delano, J. W., & Roberge, W. G. (2015). Argon diffusion in Apollo 16 impact glass spherules: Implications for 40Ar/39Ar dating of lunar impact events. Geochimica et Cosmochimica Acta, 148, 251–268. doi:10.1016/j.gca.2014.09.031
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Gupta, A. P., Taylor, W. J., McGown, L. B., & Kempf, J. G. (2014). NMR Studies of the Chiral Selectivity of Self-Assembled Guanosinemonophosphate. J. Phys. Chem. B, 118(49), 14243–14256. doi:10.1021/jp5075016
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Hardegree-Ullman, E. E., Gudipati, M. S., Boogert, A. C. A., Lignell, H., Allamandola, L. J., Stapelfeldt, K. R., & Werner, M. (2014). LABORATORY DETERMINATION OF THE INFRARED BAND STRENGTHS OF PYRENE FROZEN IN WATER ICE: IMPLICATIONS FOR THE COMPOSITION OF INTERSTELLAR ICES. The Astrophysical Journal, 784(2), 172. doi:10.1088/0004-637x/784/2/172
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Joshi, P. C., & Aldersley, M. F. (2013). Significance of Mineral Salts in Prebiotic RNA Synthesis Catalyzed by Montmorillonite. Journal of Molecular Evolution, 76(6), 371–379. doi:10.1007/s00239-013-9568-x
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Joshi, P. C., Aldersley, M. F., & Ferris, J. P. (2013). Progress in demonstrating homochiral selection in prebiotic RNA synthesis. Advances in Space Research, 51(5), 772–779. doi:10.1016/j.asr.2012.09.036
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Mojzsis, S. J., Cates, N. L., Caro, G., Trail, D., Abramov, O., Guitreau, M., … Bleeker, W. (2014). Component geochronology in the polyphase ca. 3920Ma Acasta Gneiss. Geochimica et Cosmochimica Acta, 133, 68–96. doi:10.1016/j.gca.2014.02.019
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Mueller, T., Watson, E. B., Trail, D., Wiedenbeck, M., Van Orman, J., & Hauri, E. H. (2014). Diffusive fractionation of carbon isotopes in γ-Fe: Experiment, models and implications for early solar system processes. Geochimica et Cosmochimica Acta, 127, 57–66. doi:10.1016/j.gca.2013.11.014
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Wilke, I., Ramanathan, V., LaChance, J., Tamalonis, A., Aldersley, M., Joshi, P. C., & Ferris, J. (2014). Characterization of the terahertz frequency optical constants of montmorillonite. Applied Clay Science, 87, 61–65. doi:10.1016/j.clay.2013.11.006
2014 Teams
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Arizona State University
Massachusetts Institute of Technology
NASA Ames Research Center
NASA Goddard Space Flight Center
NASA Jet Propulsion Laboratory - Icy Worlds
NASA Jet Propulsion Laboratory - Titan
Pennsylvania State University
Rensselaer Polytechnic Institute
University of Hawaii, Manoa
University of Illinois at Urbana-Champaign
University of Southern California
University of Wisconsin
VPL at University of Washington