1. Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.
2. Department of Physics, Catholic University of America, Washington, District of Columbia, USA.
3. Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, Maryland, USA.
4. Department of Biology, Georgetown University, Washington, District of Columbia, USA.
5. Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.