1 1 NASA Goddard Space Flight Center , Greenbelt, Maryland, USA .
2 2 Virtual Planetary Laboratory , Seattle, Washington, USA .
3 3 University of Colorado at Boulder , Colorado, USA .
4 4 Present address: UK Space Agency, UK .
5 5 Department of Genetics, Cell Biology and Development, University of Minnesota , Minneapolis, Minnesota, USA .
6 6 Tennessee State University , Nashville, Tennessee, USA .
7 7 Department of Physics, University of New South Wales , Sydney, Australia .
8 8 University of Westminster , London, UK .
9 9 Oberlin College , Oberlin, Ohio, USA .
10 10 Division of Biological Sciences, University of Montana , Missoula, Montana, USA .
11 11 Institute for research on exoplanets (iREx) , Université de Montréal, Montréal, Canada .
12 12 Universities Space Research Association , Mountain View, California, USA .
13 13 Blue Marble Space Institute of Science , Seattle, Washington, USA .
14 14 Southwest Research Institute , Boulder, Colorado, USA .
15 15 Mayo Clinic , Rochester, Minnesota, USA .
16 16 Instituto de Astronomía y Física del Espacio (IAFE) , UBA-CONICET, Ciudad Autónoma de Buenos Aires, Argentina .
17 17 Department of Biology, Carleton College , Northfield, Minnesota, USA .
18 18 University of Washington Astronomy Department and Astrobiology Program , Seattle, Washington, USA .
19 19 Lamont-Doherty Earth Observatory, Columbia University , Palisades, New York, USA .
20 20 Department of Biology, University of Utah , Salt Lake City, Utah, USA .
21 21 Institut für Planetologie, University of Münster , Münster, Germany .
22 22 Polar Science Center, Applied Physics Laboratory, University of Washington , Seattle, Washington, USA .
23 23 Planetary Science Institute, Research School of Earth Sciences, Research School of Astronomy and Astrophysics, The Australian National University , Canberra, Australia .
24 24 Earth and Planetary Science, McGill University , and the McGill Space Institute, Montréal, Canada .
25 25 Society for Science & the Public , Washington, DC, USA .
26 26 Carnegie Institute for Science , Washington, DC, USA .
27 27 Department of Geosciences, Weber State University , Ogden, Utah, USA .
28 28 IAM-Departamento de Fisica, CUCEI , Universidad de Guadalajara, Guadalajara, México.
29 29 Brazilian Synchrotron Light Laboratory , Campinas, Brazil .
30 30 School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia , USA .
31 31 Science Foundation Ireland , Dublin, Ireland .
32 32 Southwest Research Institute , San Antonio, Texas, USA .
33 33 School of Earth and Ocean Sciences, University of Victoria , Victoria, Canada .
34 34 American Society for Microbiology , Washington, DC, USA .
35 35 Arizona State University , Tempe, Arizona, USA .
36 36 Harvard University , Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA .
37 37 Research Centre for Astronomy and Earth Sciences , Hungarian Academy of Sciences, Budapest, Hungary .
38 38 Johnson & Wales University , Denver, Colorado, USA .
39 39 Rensselaer Polytechnic Institute , Troy, New York, USA .
40 40 Earth Life Science Institute, Tokyo Institute of Technology , Tokyo, Japan .
41 41 Laboratoire Lagrange, UMR 7293, Université Nice Sophia Antipolis , CNRS, Observatoire de la Côte d'Azur, Nice, France .
42 42 University of Central Florida , Orlando, Florida, USA .
43 43 Department of Earth Sciences, The University of Western Ontario , London, Canada .
44 44 Royal Observatory of Belgium , Brussels, Belgium .
45 45 Department of Astronomy, Harvard University , Cambridge, Massachusetts, USA .
46 46 University of St. Andrews , St. Andrews, UK .
47 47 University of Washington , Seattle, Washington, USA .
48 48 University of California , Riverside, California, USA .
49 49 Novozymes A/S, Bagsvaerd, Denmark .
50 50 School of Earth and Space Exploration and Beyond Center for Fundamental Concepts in Science, Arizona State University , Tempe, Arizona, USA .
51 51 Department of Earth and Planetary Sciences, Washington University in St. Louis , St. Louis, Missouri, USA .