[1] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA
[2] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[3] US Geol Survey, Flagstaff, AZ 86001 USA
[4] Proxemy Res, Bowie, MD 20715 USA
[5] Planetary Sci Inst, Tucson, AZ 85719 USA
[6] Wheeling Jesuit Coll, Wheeling, WV 26003 USA
[7] Stanford Univ, Stanford, CA 94305 USA
[8] NASA, Goddard Inst Space Studies, New York, NY 10025 USA
[9] Observ Paris, F-92195 Meudon, France
[10] Univ G DAnnunzio, Int Res Sch Planetary Sci, I-65127 Pescara, Italy
[11] Fac Ingn, I-80125 Naples, Italy
[12] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
[13] Univ Roma La Sapienza, I-00184 Rome, Italy
[14] Politecn Bari, Dipartimento Interateneo Fis, I-70126 Bari, Italy
[15] INFM, I-70126 Bari, Italy
[16] Agenzia Spaziale Italiana, I-00131 Rome, Italy