Presentation Information
[PPS07-P14]Experimental Constraints on Organic Molecule Evolution under Simulated Martian Surficial Conditions
*Deepali Singh1, Eloi Camprubi1,3, Tian Dong2,3 (1.School of Integrative Biological and Chemical Sciences, University of Texas Rio Grande Valley, 2.School of Earth, Environmental, and Marine Sciences, University of Texas Rio Grande Valley, 3.South Texas Space Science Institute, University of Texas Rio Grande Valley)
Keywords:
Mars,Planetary Simulation,Astrobiology,Biosignatures
The search for life on Mars is based on the longevity of biomarkers under its surficial conditions, and understanding the preservation mechanisms of the organic biomolecules is key in interpreting its geological and biological evolution. In the present work, we examine the evolution of organic molecules of biological origin under a combination of various new and previously studied physical and chemical parameters, including changing temperature, pressure, radiation, and soil composition. The experimental setup consists of a 450 W Xenon Arc lamp that simulates the Sun’s spectra in the UV-VNIR range, integrated with a multi-well sample plate. We have used the Monte Carlo approach to scale up the radiation intensity in each well to scale up to Martian number of days, taking into account multiple current measurements, randomized responsivity of the photodiode, % of UV contribution in the radiation spectra, and probability of dusty and clear skies on Mars. Our approach investigates mixing different soil substrates with three different organics of varying degrees of complexity, namely, (1) Bovine Serum Albumin, (2) Lambda phage DNA, and (3) Diplopterol, followed by simulation of various stresses within a controlled lab simulator setup.
Following the controlled exposure, we systematically evaluate both qualitative and quantitative changes in the composition of the organic molecules using UV-VIS spectroscopy and SDS Gel electrophoresis for bulk degradation and Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-Mass Spectrometry (LC-MS) for analysis of the breakdown products. Our preliminary data suggest that the preservation potential is dependent on the substrate composition and molecular complexity of the original organics. Different soil compositions with varying physical parameters are designed to simulate high-energy locales in tandem to develop improved detection abilities. Therefore, our results provide insights into the probability of organic molecules surviving over time on larger time scales and help in elucidating areas that may have relatively better preservation potential based on geological composition for future astrobiologically-oriented missions.
Following the controlled exposure, we systematically evaluate both qualitative and quantitative changes in the composition of the organic molecules using UV-VIS spectroscopy and SDS Gel electrophoresis for bulk degradation and Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-Mass Spectrometry (LC-MS) for analysis of the breakdown products. Our preliminary data suggest that the preservation potential is dependent on the substrate composition and molecular complexity of the original organics. Different soil compositions with varying physical parameters are designed to simulate high-energy locales in tandem to develop improved detection abilities. Therefore, our results provide insights into the probability of organic molecules surviving over time on larger time scales and help in elucidating areas that may have relatively better preservation potential based on geological composition for future astrobiologically-oriented missions.