1. Department of Physics (Atmospheric, Oceanic and Planetary Physics), University of Oxford , Oxford OX1 3PU , UK
2. Laboratoire Lagrange, Observatoire de la Côte d’Azur, Université Côte d’Azur, CNRS , Boulevard De L’Observatoire, CS 34229, F-06304 Nice cedex 4 , France
3. School of Earth & Space Exploration, Arizona State University , Tempe, AZ 85287 , USA
4. Center for Space and Habitability, University of Bern , Gesellschaftsstrasse 6, CH-3012 Bern , Switzerland