¹A.Longobardo et al. (>10)
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2017.12.011]
¹INAF-IAPS, via Fosso del Cavaliere 100, I-00133 Rome, Italy
Copyright Elsevier

We studied the distribution in the Urvara-Yalode region of Ceres (latitudes 21-66°S, longitudes 180-360°E) of main spectral parameters derived from the VIR imaging spectrometer onboard the NASA/Dawn spacecraft, as an overall study of Ceres mineralogy reported in this special issue. In particular, we analyzed the distribution of reflectance at 1.2 μm, band depth at 2.7 and 3.1 μm, ascribed to magnesium and ammoniated phyllosilicates, respectively.

Whereas the average band depths of this region are lower than eastern longitudes, reflecting the E-W dichotomy of abundance of phyllosilicates on Ceres, spectral variations inside this region are observed in the following units: a) the central peak of the Urvara crater (45.9°S, 249.2°E, 170 km in diameter), showing a deep 3.1 μm band depth, indicating an ammonium enrichment; b) the cratered terrain westwards of the Yalode basin (42.3°S, 293.6°E, 260 km in diameter), where absorption bands are deeper, probably due to absence of phyllosilicates depletion following the Yalode impact; c) the hummocky cratered floor of Yalode and Besua (42.4°S, 300.2°E) craters, characterized by lower albedo and band depths, probably due to different roughness; d) Consus (21°S 200°E) and Tawals (39.1°S, 238°E) craters, whose albedo and band depths decreasing could be associated to different grain size or abundance of dark materials. Twenty-two small scale (i.e., lower than 400 m) bright spots are observed: because their composition is similar to the Ceres average, a strong mixing may have occurred since their formation.

¹M. Naito, ^1,2N. Hasebe, ²H. Nagaoka, ²E. Shibamura, ³M. Ohtake, ⁴K.J. Kim, ⁵C. Wöhler, ⁶A.A. Berezhnoy
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2017.12.005]
¹School of Advanced Science and Engineering, Waseda University, Japan
²Research Institute for Science and Engineering, Waseda University, Japan
³Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Japan
⁴Korea Institute of Geoscience and Mineral Resources, South Korea
⁵Image Analysis Group, TU Dortmund University, Germany
⁶Sternberg Astronomical Institute, Moscow State University, Russia
Copyright Elsevier

In this study we describe the distribution of iron on the Moon as obtained by the Kaguya high energy resolution gamma-ray spectrometer (KGRS). We achieved for the first time the identification of iron based on the fast neutron flux obtained by the KGRS. The iron distribution obtained by KGRS is compared to that of the Lunar Prospector Gamma-Ray Spectrometer (LP GRS), showing that the FeO distributions observed by KGRS and LP GRS, in general, are in good agreement. Furthermore, we compare the iron content data obtained by KGRS and LP GRS to spectral reflectance measurements of the Clementine, Kaguya and Chandrayaan-1 spacecraft as well as those inferred from returned samples. We found differences in FeO concentration and distribution in areas of moderate abundance (6-15 wt%) of the South Pole-Aitken basin, Mare Orientale, and around the crater Tycho crater. It implies that high concentrations of FeO at Mare Ingenii in the South Pole-Aitken basin and Mare Orientale are due to the presence of mare basalts, whereas the enriched FeO content in the central depression of the South Pole-Aitken basin and the Tycho crater indicates the presence of mafic materials such as impact melt breccia.