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Early Scientific Influences Backyard and camping Star gazing Alley Pond Park Hayden Planetarium Growing up in NYC in 1950’s-1960’s Hollis, Queens: -3 min for blast to arrive -slow roasting zone. Major Influence: Science Fiction The Plan Major in physics, get Ph.D. Become an astronomer Discover the answer to the big questions: come How did the universe begin, what came before and what will after? Assuming that there are other life forms out there – how can we make contact (or have we already)? Is our “universe” the only universe, or is there really a parallel universe where there is a weak Captain Kirk and an emotional Mr. Spock? What really happened Went to SUNY Stony Brook in 1970 at age of 16 Failed Physics (see above) Spent two years studying marine invertebrate zoology Transferred to SUNY Buffalo and chemistry major Went to grad school at Univ of Washington in analytical chemistry At age of 25 began academic career Fast forward 3 decades – joined astrobiology team at RPI and returned to those questions that motivated me to become a scientist What I Learned Don’t be afraid to fail Don’t be deterred by failure There are NO musical, poetical, metaphysical, pharmceutical or other short cuts to finding answers to scientific questions There ARE many career paths that allow us to explore the fundamental questions that led us to become scientists in the first place Analytical Chemistry – the science of measurements How can we answer questions about the nature of matter in all forms, its behavior, interactions, origins, fate......... ? Design techniques to probe matter: Spectroscopy (interactions of light with matter) Mass spectrometry Electrochemistry Radioactivity Of these, spectroscopy is best suited to remote studying extraterrestrial matter - light penetrates space, is readily detected, travels quickly (!) Key Concepts in Analytical Chemistry Detectability – how low can you go? What does it mean if a signal is NOT detectable? Sensitivity – how small a change can be detected? Precision – how reproducible is a measurement? Accuracy – how close is the experimental value to the “true value” These concepts are fundamental to all scientific inquiries! Astrobiology poses enormous analytical challenges! Measurements of distant objects using remote observations to isolate signals of interest from large background signals Collection and analysis of extraterrestrial samples without contamination Analysis of ancient terrestrial samples that have experienced the history of Earth Theories of origins based only on what we can observe today, without physicochemical context Astrobiology Roadmap Goal 1: Understand how life arose on the Earth. Goal 2: Determine the general principles governing the organization of matter into living systems. Goal 3: Explore how life evolves on the molecular, organism, and ecosystem levels. Goal 4: Determine how the terrestrial biosphere has co-evolved with the Earth. Goal 5: Establish limits for life in environments that provide analogues for conditions on other worlds. Goal 6: Determine what makes a planet habitable and how common these worlds are in the universe. Goal 7: Determine how to recognize the signature of life on other worlds. Goal 8: Determine whether there is (or once was) life elsewhere in our solar system, particularly on Mars and Europa. Goal 9: Determine how ecosystems respond to environmental change on time-scales relevant to human life on Earth. Goal 10: Understand the response of terrestrial life to conditions in space or on other planets. Origins of Life on Earth: Some Key Questions Did earliest life involve biomolecules as they exist now, or earlier “proto” versions? Work backward from life as we know it (e.g., abiotic synthesis of RNA) AND work forward: What molecules were in greatest abundance? How/why did they assemble? Random chain extension or templated? Why “cells”? Why compartmentalize in earliest life? Why is chirality intrinsic to (all?) life on earth and how was one enantiomer selected over the other? Current Projects G/C/A/U or T - Why guanosine? What are the effects of amino acids, sugars, other molecules on RNA oligomerization and chirality? How can we template formation of RNA using particulates as well as small molecules? Future Directions Primitive precursors to RNA and other modern day molecules of life Common ancestor/single source based on DNA which came much later Watson-Crick G-Tetrad Guanosine Self-Association Leads to Gel Formation H-bonded “G-tetrads” self-assemble (aided by metals cations) into CHIRAL “G-wires” that further assemble into liquid crystalline phases at higher monomer concentrations Cholesteric Phase Hexagonal Phase G. Gottarelli et.al, Liquid Crystals 1997, 22, 563. P. Mariani et.al, Biophys. J. 1998, 74, 430. Mezzina, E. etc. Chem. Eur. J. 2001, 7(2), 388-395 Pieraccini, S. etc. Mol. Cryst. Liq. Cryst. (2003), 398 57-73 Microbes and microbial communities are often studied and classified using 16S rDNA gene sequencing – highly sensitive to subtle differences We are working on improved approaches that will separate DNA fragments based not only on length but also sequence – greatly facilitate rapid acquisition of data reflecting true diversity of these complex systems