INVESTIGATION OF THE ENANTIOMERIC IMBALANCE IN THE SOLAR SYSTEM THROUGH ULTRAVIOLET SPECTROPOLARIMETRY

Introduction

Amino acids and the reference nucleobases for RNA and DNA can be formed in space ice under high energy, vacuum ultraviolet (VUV) irradiation. This statement is based on twenty years of laboratory research and has profound implications in the understanding of the emergence of life in the Cosmos, the universality of the processes involved, and the compatibility of life forms across the Universe.

Need for Field Measurements

However, this laboratory work still needs to be confronted with actual, on-field measurements. Promising data have been obtained through in-situ techniques, including:

1. The analysis of carbonaceous chondrites such as the Murchison meteorite.
2. The detection of Glycine in the coma of comet 67P/Churyumov-Gerasimenko.

Unfortunately, neither of these techniques suits well for a systematic investigation. Meteorites reaching the Earth's surface represent a reduced and biased subset, and contamination by Earth-based amino acids needs to be carefully controlled.

Challenges of Space Probes

Space probes such as Rosetta are very costly and limited in scope given the constraints in space navigation. Thus, it is crucial to develop remote detection techniques to carry out a comprehensive study of the distribution of amino acids within the Solar System, their relative abundances, and their enantiomeric imbalance. According to recent estimates, this is possible at VUV wavelengths for optically active amino acids such as the very abundant alanine.

Study of VUV Radiation Interaction

The interaction between VUV radiation and optically active amino acids in space bodies is yet poorly studied. The following aspects need to be quantified prior to any attempt of remote detection in the Solar System:

• The formation of crystallites and complex structures.
• The interaction between the various molecules.
• The dependence on the VUV photon energy, polarization, and flux.

Project Aim

This project aims to carry out such an in-depth study and develop a laboratory prototype of the instrument to make, at the least, alanine remote detection feasible by a small probe navigating the asteroid belt.