Comprendre la formation et les propriétés des aérosols de Titan en laboratoire avec l'expérience PAMPRE
Résumé
In order to support the treatment and interpretation of data collected by the Cassini-Huygens mission orbiting Saturn, our team developped a laboratory experiment (Szopa et al. 2006) based on a radio-frequency reactive plasma to produce analogues of Titan's aerosols (or "tholins"). This experiment, named PAMPRE, enables to produce tholins under variable controlled conditions compatible with the present and past Titan's upper atmosphere ones. The studies we do with PAMPRE can be shared in three main actions: 1. Study the physical and chemical properties of tholins. This part is originally the most important one since it is partly dedicated to produce reference data which can be compared with observational data. We also study the influence of the production conditions on the tholins properties to better understand the context in which Titan's aerosols can be produced (Gautier et al. 2012). 2. Characterize the plasma chemistry in order to constrain the chemical pathways leading to the production of solid organic particles directly from the gaseous phase. This part is correlated to the chemistry that occurs in Titan's atmosphere to generate the aerosols (Gautier et al. 2011, Carrasco et al. 2012). 3. Characterize the physical properties of the plasma. This original task is very important to understand the influence the context in which the tholins are produced in the experimental set-up. This makes easier the transposal of our results obtain in laboratory to the Titan's atmosphere. The goal of this paper is to present an overview of results obtained in the different branches of study of Titan's tholins with the PAMPRE experiment, with an emphasize on the most recent ones.