20-EPN-084: Converting one amino acid to the other containing sulfur via ion irradiation : Implication to chemical evolution on Europa surface ices

Visit by Rahul Kumar Kushwaha, Physical Research Laboratory, Ahmedabad (India) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 8-19 December 2021

Report Summary: The non-equilibrium chemistry driven by the charged particle and photon irradiation processes are responsible for the rich chemistry on the surfaces of icy satellites. Among the icy satellites of the Jovian and Saturnian planetary systems, a few satellites such as Ganymede, Europa, Dione, Rhea, Callisto and Titan that are embedded in their respective planetary magnetospheres were observed to undergo rich chemical processes due to the bombardment of a wide range of energetic atomic and molecular ions that are present in their planet’s magnetospheres, which processes the icy surfaces of satellites by irradiation and implantation. Magnetospheres also help in bringing new species from one satellite to the other. Especially in the Jupiter system of icy satellites, sulfur transfer from Io to the other satellites is quite likely. The sulfur ions from Io are picked up by the magnetosphere and are accelerated towards the other icy satellites; Europa being the closest neighbour to Io will be implanted with sulfur ions. The Jovian satellites, due to the presence of the Jupiter’s magnetosphere, are subjected to highly energetic S ion irradiation which leads to a range of chemical activity on their surfaces. In this project, we have studied the effect of S ion irradiation on Aspartic acid for a range of energies at two different temperatures (100 K, 20 K), where the 100 K experiments are aimed to mimic the conditions of Europa. The irradiated residue was then analysed using an optical microscope, scanning electron microscope and liquid chromatography mass spectrometry.

Full scientific report published by kind permission of Rahul Kumar Kushwaha

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