TOWARDS THE DETECTION OF EXOPLANET BIOSIGNATURES WITH LARGE AMPLITUDE MOTIONS USING HIGH RESOLUTION SPECTROSCOPY – EXOBIOLAM

The search for life in the Universe is a tremendous motivation for the detection of planets beyond our Solar system. Launched at the end of 2021 the James Webb Space Telescope (JWST) allows us to study the atmospheres of the vast diversity of exoplanets. Following the groundbreaking advancements of the telescopes (present and future such as the ARIEL mission set to launch in 2029), the search for "habitable" exoplanets with stable atmospheres and biosignature gases have enter a new phase. Biosignature gases are produced by living organisms that accumulate in the atmosphere to detectable levels and would be sign of an extraterrestrial life. High resolution spectroscopic data plays a crucial role in the characterization of exoplanets. Spectroscopy can quantify the abundances of various molecular species, which in turn helps deducing the compositions and physical conditions of these planet’s atmospheres. The retrieval of exoplanets atmospheric composition heavily relies on molecular spectroscopy. However, the lack of laboratory data on many molecular species, on particularly for molecules containing one or two methyl group(s) internal rotor(s referred as a “Large Amplitude Motion(s)” (LAMs), presently limits the modelling of exoplanets. To address this limitation laboratory spectroscopy is required.The first objective of the EXOBIOLAM project is to fill the missing gap in high-resolution spectroscopy studies for molecules containing one or two LAM(s) with original theoretical, analytical and experimental developments. The second objective is to integrate this spectroscopic data into an advanced model coupling chemical kinetics and retrieval for exoplanets, studying planetological molecules beyond the primary ones (CO, CO2, H2O, CH4 , NH3) to prepare the future observations.