¹Varmuza, K., ¹Filzmoser, P., ²Hilchenbach, M., ²Krüger, H., ³Silén, J.
¹Vienna University of Technology, Department of Statistics and Probability Theory, Vienna, Austria
²Max Planck Institute for Solar System Research, Göttingen, Germany
³Finnish Meteorological Institute, Helsinki, Finland

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

Reference
Varmuza K, Filzmoser P, Hilchenbach M, Krüger H, Silén J (2014) KNN classification – evaluated by repeated double cross validation: Recognition of minerals relevant for comet dust. Chemometrics and Intelligent Laboratory Systems 138, 64-71.
Link to Art[DOI: 10.1016/j.chemolab.2014.07.011]

^1,2Masateru Ishiguro et al. (>10)*
¹Department of Physics and Astronomy, Seoul National University, Gwanak, Seoul 151-742, Korea
²Visiting Scientist, Institut de Mecanique Celeste et de Calcul des Ephemerides, Observatoire de Paris, 77 Avenue Denfert Rochereau, F-75014 Paris, France.
*Find the extensive, full author and affiliation list on the publishers website

We investigated the magnitude-phase relation of (162173) 1999 JU3, a target asteroid for the JAXA Hayabusa 2 sample return mission. We initially employed the International Astronomical Union’s H-G formalism but found that it fits less well using a single set of parameters. To improve the inadequate fit, we employed two photometric functions: the Shevchenko and Hapke functions. With the Shevchenko function, we found that the magnitude-phase relation exhibits linear behavior in a wide phase angle range (α = 5°-75°) and shows weak nonlinear opposition brightening at α < 5°, providing a more reliable absolute magnitude of H V = 19.25 ± 0.03. The phase slope (0.039 ± 0.001 mag deg–1) and opposition effect amplitude (parameterized by the ratio of intensity at α = 0fdg3 to that at α = 5°, I(0fdg3)/I(5°) = 1.31 ± 0.05) are consistent with those of typical C-type asteroids. We also attempted to determine the parameters for the Hapke model, which are applicable for constructing the surface reflectance map with the Hayabusa 2 onboard cameras. Although we could not constrain the full set of Hapke parameters, we obtained possible values, w = 0.041, g = –0.38, B 0 = 1.43, and h = 0.050, assuming a surface roughness parameter $\bar{\theta }$ = 20°. By combining our photometric study with a thermal model of the asteroid, we obtained a geometric albedo of p v = 0.047 ± 0.003, phase integral q = 0.32 ± 0.03, and Bond albedo A B = 0.014 ± 0.002, which are commensurate with the values for common C-type asteroids.

Reference
Ishiguro M et al. (2014) Optical Properties of (162173) 1999 JU3: In Preparation for the JAXA Hayabusa 2 Sample Return Mission. The Astrophysical Journal 792, 74.
Link to Article [doi:10.1088/0004-637X/792/1/74]

¹Christoph Loesche, ¹Jens Teiser, ¹Gerhard Wurm, ¹Alexander Hesse, ^2,3Jon M. Friedrich, ⁴Addi Bischoff
¹Faculty of Physics, University of Duisburg-Essen, Lotharstrasse 1, D-47057 Duisburg, Germany
²Department of Chemistry, Fordham University, Bronx, NY 10458, USA
³Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 10024, USA
⁴Institut für Planetologie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 10, D-48149 Münster, Germany

Photophoretic motion can transport illuminated particles in protoplanetary disks. In a previous paper, we focused on the modeling of steady state photophoretic forces based on the compositions derived from tomography and heat transfer. Here, we present microgravity experiments which deviate significantly from the steady state calculations of the first paper. The experiments on average show a significantly smaller force than predicted with a large variation in absolute photophoretic force and in the direction of motion with respect to the illumination. Time-dependent modeling of photophoretic forces for heat-up and rotation shows that the variations in strength and direction observed can be well explained by the particle reorientation in the limited experiment time of a drop tower experiment. In protoplanetary disks, random rotation subsides due to gas friction on short timescales and the results of our earlier paper hold. Rotation has a significant influence in short duration laboratory studies. Observing particle motion and rotation under the influence of photophoresis can be considered as a basic laboratory analog experiment to Yarkovsky and YORP effects.

Reference
Loesche C, Teiser J, Wurm G, Hesse A, Friedrich JM, Bischoff A (2014) Photophoretic Strength on Chondrules. 2. Experiment. The Astrophysical Journal, 792, 73.).
Link to Article[doi:10.1088/0004-637X/792/1/73]

^1,2A. A. Nemchin,³M. Humayun,¹M. J. Whitehouse,^4,5R. H. Hewins,⁶J-P. Lorand,⁷A. Kennedy,²M. Grange,⁴B. Zanda,⁴C. Fieni, ⁸D. Deldicque

¹Department of Geosciences, Swedish Museum of Natural History, SE-104 05 Stockholm, Sweden
²Department of Applied Geology, Curtin University, Perth, Western Australia 6845, Australia
³Department of Earth, Ocean & Atmospheric Science and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
⁴Institut de Minéralogie de Physique des Matériaux et Cosmochimie (IMPMC), Sorbonne Université, Muséum National d’Histoire Naturelle, UPMC Université Paris 06, 61 rue Buffon, F-75005 Paris, France
⁵Department of Earth & Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA
⁶Laboratoire de Planétologie et Géodynamique de Nantes, CNRS UMR 6112, Université de Nantes, 2 Rue de la Houssinière, BP 92208 44322 Nantes Cédex 3, France
⁷Department of Applied Physics, Curtin University, Perth, Western Australia 6845, Australia
⁸Ecole Normale Supérieure, UMR 8538, 75231 Paris CEDEX 5, France

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

Reference
Nemchin AA, Humayun M, Whitehouse MJ, Hewins RH, Lorand J-P, Kenendy A, Grange M, Zanda B, Fienei C, Deldicque D (2014) Record of the ancient martian hydrosphere and atmosphere preserved in zircon from a martian meteorite. Nature Geoscience (in Press)
Link to Article [doi:10.1038/ngeo2231]

¹Martin Beech
¹Campion College, University of Regina, Regina, SK, S4S 0A2, Canada

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

Reference
Beech M (2014) Grazing Impacts Upon Earth’s Surface: Towards an Understanding of the Rio Cuarto Crater Field. Earth, Moon, and Planets (in Press)
Link to Article [10.1007/s11038-014-9445-7]