1. UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
2. Austrian Academy of Sciences, Space Research Institute, Graz, Austria.
3. Division of Space Technology, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Kiruna, Sweden; and Instituto Andaluz de Ciencias de la Tierra (CSIC-UGR), Armilla, Granada, Spain.
4. Department of Reference Systems and Planetology, Royal Observatory of Belgium, Brussels, Belgium.
5. School of Physics and Astronomy, University of St Andrews, St Andrews, UK; now at the Carl Sagan Institute, Cornell University, Ithaca, NY, USA.
6. Centre for Ocean and Atmospheric Science (COAS), School of Environmental Sciences, University of East Anglia, Norwich, UK.
7. Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, Madrid, Spain.