[1] NASA, Div Earth & Space Sci, JPL, Pasadena, CA 91109 USA
[2] Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England
[3] Mt San Antonio Coll, Dept Geol, Walnut, CA 91789 USA
[4] DLR, Inst Planetaty Explorat, Berlin, Germany
[5] Univ Nantes, Lab Planetol & Geodynam, Nantes, France
[6] US Geol Survey, Fed Ctr, Lakewood, CO 80225 USA
[7] NASA AMES, Moffett Field, CA 94035 USA
[8] Observ Paris, F-92195 Meudon, France
[9] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[10] Univ Pittsburgh, Pittsburgh, PA 15260 USA
[11] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA
[12] Observ Paris, Off Director, F-75014 Paris, France
[13] Ist Astrofis Spaziale Fis Cosm, I-00133 Rome, Italy
[14] Univ Paris 11, Fac Sci, F-91405 Orsay, France
[15] Univ Washington, Winthrop, WA 98862 USA
[16] Osserv Astron Capodimonte, I-80131 Naples, Italy
[17] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA