1. Division of Geological and Planetary SciencesCalifornia Institute of Technology Pasadena CA USA
2. Jet Propulsion LaboratoryCalifornia Institute of Technology Pasadena CA USA
3. Helmholtz Centre Potsdam, German Research Center for Geosciences (GFZ) Potsdam Germany
4. NASA Goddard Space Flight Center Greenbelt MD USA
5. SRON Netherlands Institute for Space Research Utrecht Netherlands