Theoretical studies about an extraterrestrial origin of prebiotic species
type: Dataset
description: The hunt for prebiotic species in the interstellar medium is a major concern for understanding the possible role of interstellar chemistry in the synthesis of the molecules at the origin of life. This study was motivated by the fact that some amino acids are currently identified in meteorites but none are yet observed in the interstellar medium. On the one hand, we use DFT and ab-initio methods of quantum chemical calculations to study the relative stability of the isomers detected in the interstellar medium. This study leads to a "Minimum Energy Principle" (MEP) specifying that the most thermodynamically stable isomer corresponds to the larger abundance observed. Applying this principle, we evaluate the possibility of detecting new prebiotic species, particularly amino acids, in the interstellar medium. Then, within the same approach, we verify that the link between abundance and thermodynamic order is valid for amino acids in the meteorites, which allows us to constrain the formation conditions in the parent bodies. On the other hand, we use the plane-wave periodic method in order to study the sticking of molecular species on carbonaceous and icy interstellar grains. We show that there is an efficient selective adsorption for the different isomers. This could lead to an observational bias for the relative abundances of these isomers, which could provide a possible explanation for the few exceptions to the MEP.
identifier: NNT: 2008PA066467
issued: 2026-05-11T13:15:24.327880
language: fr
modified: 2026-05-11T13:15:24.327886
contact point: Organization
  fn: CCSD
keyword: acides-amines
keyword: adsorption
keyword: amino-acids
keyword: astrobiology
keyword: chimie-quantique
keyword: chimtheochemical-sciencestheoretical-andor-physical-chemistry
keyword: exobiologie
keyword: infoeu-reposemanticsdoctoralthesis
keyword: interstellar-medium
keyword: meteorites
keyword: milieu-interstellaire
keyword: molecules-prebiotiques
keyword: prebiotic-species
keyword: quantum-chemistry
keyword: theses
landing page: https://theses.hal.science/tel-00812072

Theoretical studies about an extraterrestrial origin of prebiotic species
type: Distribution
format: HTML
issued: 2026-05-11T13:15:24.372939
modified: 2026-05-11T13:15:24.302204
access URL: https://theses.hal.science/tel-00812072

test_moissonnage_selune
type: Agent