1. BEYOND: Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona.
2. Foundation for Applied Molecular Evolution, Gainesville, Florida.
3. Department of Philosophy and the Center for Astrobiology, University of Colorado, Boulder, Colorado.
4. Planetary Science Institute, Research School of Astronomy and Astrophysics & Research School of Earth Sciences, Australian National University, Canberra, Australia.
5. Space Science Division, NASA Ames Research Center, Moffett Field, California.
6. Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts.