Séminaires LLR

Understanding the Origin of Chiral Molecules in Interstellar Space

by Cornelia Meinert (Institut de chimie de Nice)

Seminar room (LLR)

Seminar room


The original appearance of chiral organic molecules in our universe is an essential component of the asymmetric evolution of life on Earth. Simulated cometary ice experiments have indicated that circularly polarised light could be the initial source of life's handedness following prebiotic astrochemical condensation of primordial gases. With advanced analytical techniques, chiral sugar molecules1 including ribose (Fig.1), amino acids2 and/or their molecular precursors produced within these interstellar achiral ice analogues have been detected and are likely to be abundant in interstellar media. These molecular species are considered key prebiotic intermediates in the first steps towards the formation of biomolecular homochirality. Moreover, enantiomeric excesses have been produced in the cometary ice simulations either by photolytic degradation of racemates3 or by photochemical synthesis via transfer of chiral photons4. The significance of these results will be considered with reference to the Rosetta space probe that successfully deposited the Philae Lander on the nucleus of comet 67P/Churyumov-Gerasimenko in November 20145. The analysis of the formation of enantiomer-enriched amino acid and sugar structures within interstellar ices, both simulated and actual, should serve as a means towards furthering understanding the origin of asymmetric prebiotic molecules. [1] C. Meinert et al., Science 352, 208 (2016); P. de Marcellus & C. Meinert et al., Proc. Natl. Acad. Sci. USA 112, 965 (2015) [2] G.M. Munoz Caro et al., Nature 416 403 (2002); C. Meinert et al. ChemPlusChem 77, 186 (2012) [3] C. Meinert et al., Angewandte Chemie Int. Ed. 53, 210 (2014) [4] P. de Marcellus & C. Meinert et al., Astrophys. J. Lett 727, L27 (2011) [5] F. Goesmann et al., Science 349, 497 (2015)