Anomalously porous and dark rocks on asteroid ( 162173 )

T. Okada2, T. Fukuhara1, L. Riu2, S. Sugita3, R. Honda4, T. Morota3, S. Kameda1, Y. Yokota2, E. Tatsumi5,2, K. Yumoto2, N. Hirata6, A. Miura2, T. Kouyama7, H. Senshu8, Y. Shimaki2, T. Arai9, J. Takita10, H. Demura6, T. Sekiguchi11, T. G. Müller12, A. Hagermann13, J. Biele14, M. Grott14, M. Hamm14,15, M. Delbo16, W. Neumann13,17, M. Yamada8, H. Suzuki18, C. Honda6, K. Ogawa19, M. Hayakawa2, K. Yoshioka3, M. Matsuoka2, Y. Cho3, H. Sawada2, K. Kitazato6, T. Saiki2, H. Imamura2, Y. Takagi20, H. Yano2, K. Shirai21, S. Nakazawa2, M. Arakawa21, K. Wada8, T. Kadono22, K. Ishibashi8, 1Rikkyo University, Japan. (sakatani@rikkyo.ac.jp) 2Institute of Space and Astronautical Sciences, Japan Aerospace Exploration Agency, Japan. 3University of Tokyo, Japan. 4Kochi University, Japan. 5Instituto de Astrofisica de Canarias, University of La Laguna, Spain. 6University of Aizu, Japan. 7National Institute of Advanced Industrial Science and Technology, Japan. 8Chiba Institute of Technology, Japan. 9Ashikaga University, Japan. 10Hokkaido Kitami Hokuto High School, Japan. 11Hokkaido University of Education, Japan. 12Max-Planck Institute for Extraterrestrial Physics, Germany. 13University of Stirling, UK. 14German Aerospace Center (DLR), Germany. 15University of Potsdam, Germany. 16Observatoire de la Côte d’Azur, CNRS, France. 17Universität Heidelberg, Germany. 18Meiji University, Japan. 19JAXA Space Exploration Center, Japan Aerospace Exploration Agency, Japan. 20Aichi Toho University, Japan. 21Kobe University, Japan. 22University of Occupational and Environmental Health, Japan.