The formation of organic molecules in solar system environments: The Miller-Urey Experiment in Space preflight overview

The Miller-Urey Experiment in space (MUE) will investigate the formation of prebiotic organic compounds in the early solar system environment when it is sent to, and later retrieved from, the International Space Station in 2012. The dynamic environment of the solar nebula with the simultaneous presence of gas, particles, and energetic processes, including shock waves, electrical discharges, and radiation may trigger a rich organic chemistry leading to organic molecules. Two gas mixture compositions (CH4, NH3, H2 and N2, H2, CO) will be tested and subjected to continuous spark discharges for 48, 96, and 192 hours. Silicate particles will serve as surfaces on which thin water ice mantles can accrete. The experiment will be performed at low temperatures (-5 °C), slowing hydrolysis and improving chances of detection of initial products, intermediates and their abundances. Conducting the Miller-Urey experiment in the space environment (microgravity) allows us to simulate conditions that could have prevailed in the low gravity, energetic early solar nebula and provides insights into the chemical pathways that may occur as planetary systems form.