1. Department of Earth and Planetary Sciences; University of California Davis; One Shields Avenue Davis California 95616 USA
2. Key Laboratory of Lunar and Deep Space Exploration; National Astronomical Observatories; Chinese Academy of Sciences; Beijing 100012 China
3. State Key Laboratory of Lithospheric Evolution; Institute of Geology and Geophysics; Chinese Academy of Sciences; Beijing 100029 China
4. Hawai‘i Institute of Geophysics and Planetology; University of Hawai‘i at Manoa; Honolulu Hawai‘i 96822 USA
5. SETI Institute; 189 Bernardo Avenue Mountain View California 94043 USA
6. NASA Ames Research Center; Mail Stop 245-1 Moffett Field California 94035 USA