Porosity Gradient at the Surface of Comet 67P/Churyumov-Gerasimenko

Chariton Christou, Heriot-Watt University, Edinburgh, EH14, United Kingdom, S Kokou Dadzie, Heriot-Watt University, Edinburgh, United Kingdom, Nicolas Thomas, Physikalisches Inst, Bern, Switzerland; University of Bern, Bern, Switzerland, Paul Hartogh, MPI for Solar System Research, Katlenburg-Lindau, Germany, Laurent Jorda, Aix Marseille University, Marseille Cedex 03, France, Ekkehard Kuhrt, DLR, Berlin, Germany, Ian Wright, Open University, Milton Keynes, United Kingdom and John Zarnecki, International Space Science Institute, Bern, Switzerland