1. Geology and Geophysics; Louisiana State University; Baton Rouge Louisiana USA
2. Earth and Atmospheric Sciences; Georgia Institute of Technology; Atlanta Georgia USA
3. Université de Toulouse [UPS; OMP; IRAP]; Toulouse France
4. CNRS [UMR 5277], Institut de Recherche en Astrophysique et Planétologie; Toulouse France
5. Department of Geosciences; Stony Brook University; Stony Brook New York USA
6. Department of Astronomy; Cornell University; Ithaca New York USA
7. Department of Planetary Sciences; University of Arizona; Tucson Arizona USA
8. SETI Institute; Mountain View California USA