Part of my research is dedicated to the origin and evolution of organic matter in solar system bodies. The most interesting objects to start with are meteorites, particularly carbonaceous chondrites (CI, CM, CR) because they are rich in organic matter and available for laboratory measurements on Earth. They are asteroid fragments, remnant of the birth of our solar system. Hence, they should contain pristine organic matter, witness of the chemical composition in the early solar system. This work is related to the search of the origin of life in Exobiology, considering an exogenous origin of the organic matter.

By doing experimental studies, I emulate the evolution of organic matter during aqueous alteration. This starts from abiotically synthesized OM, as it would form during evolution of interstellar ices to the solar nebula (see interstellar ices topic) or from model molecules, such as hexamethylenetetramine, HMT (recently observed in meteorites). Such aqueous process occurred in parent bodies of carbonaceous chondrites or on Mars surface, and still occur in icy moons. I particularly develop the coupling between organic matter and minerals in such systems, to search for their respective impact and the final preservation of organic matter in mineral matrices. These experiments provide data to help observations and interpretations from asteroids, Mars and or icy moons. This research is in support to spatial missions, searching for organic matter in extreme environments.

 Carbonaceous Meteorites

Meteorites contain a wide range of organic compounds. It is still unclear when, where and how these compounds are formed. Especially, in addition to history of organic matter before accretion in asteroid body, carbonaceous asteroids have (almost) all being submitted to aqueous alteration. Phyllosilicates, carbonates, oxides and other minerals clearly attest of such process in carbonaceous meteorites. The impact of aqueous alteration on accreted organic matter remains debate, while it is chemically impossible that the organic matter would have not been impacted, at least first by the phase transition between solid and liquid (fusion). Accreted organic matter were likely embedded in ices or stuck on mineral grains (dust). Asteroids have accreted dust, minerals, ices, and with the minerals they also accreted radionuclides, such as Aluminium 26. Due to the desintegration of these latter components, asteroids have been more or less heated during few millions years. Fortunately for the carbonaceous asteroids, the accreted ices (indirectly related to the organic matter content) have reduced the heating by the melting of ices. In turns, this "water circulation" has transformed the primary minerals. Orgueil, the most aqueously altered meteorite presents only a composition of hydrated minerals, no primary mineral remains. Others carbonaceous chondrites present different degree of aqueous alteration.