Impact of Planetary magnetization on Atmospheric erosion.

The BRAIN/IPA project aims at building a semi-empirical model describing the effect of the planetary magnetic field on atmospheric erosion in order to assess how it has affected the past evolution of the atmospheres of Venus, Earth and Mars. The PRODEX/Cluster project is more oriented toward the analysis of Cluster observations (four identical scientific spacecraft launched in 2000 and still operating) with a focus on the energy, mass and current conservation between the various plasma reservoirs in the Earth’s magnetosphere. This project aims at studying the evolution and stability of the atmospheres of Venus, Earth and Mars and thus fits in BIRA-IASB’s core mission of studying atmospheres. More particularly, it will focus on atmospheric loss into space that is currently dominated by ion outflow processes. On one side, planetary atmospheres belong to the non-living world. On the other side,the presence of an atmosphere and of water on a planet represent a favorable environment for the development of life (at least for the forms of life we know). Studying the evolution and stability of the atmospheres of solar system rocky planets means studying how the non-living word can provide favorable conditions for the development of the living word, i.e. for the habitability of those planets. The Space Physics Division (D10) division of BIRA/IASB has a long expertise on the study ion outflow processes both on theoretical aspects (it has been a leader in the development of polar wind and auroral outflow models during the last decades) and on experimental and observational aspects (it is strongly involved in the  Cluster mission since more than 20 years). This project therefore exploits the long-term  expertise of BIRA-IASB. We are also convinced that this project can help build bridges between the D10 division and the D20 division (Atmospheric composition: sources and sinks) which expertise includes the neutral atmospheres of Venus and Mars.