Institution: | a Planetary Systems Laboratory, Code 693, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA b LATMOS, CNRS, UPMC Univ. Paris 06, 75005 Paris, France c Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA d I.Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany |