1. University of New Mexico, Department of Earth and Planetary Sciences, Albuquerque, New Mexico 87131, USA
2. Massachusetts Institute of Technology, Department of Earth, Atmospheric and Planetary Sciences, Cambridge, Massachusetts 02139, USA
3. University of Wisconsin–Madison, Department of Physics, Madison, Wisconsin 53706, USA
4. Harvard University, Department of Organismic and Evolutionary Biology, Cambridge Massachusetts 02138, USA
5. University of Wisconsin–Madison, Departments of Chemistry and Geoscience, Madison, Wisconsin 53706, USA