Suchergebnisse

The analysis of hyper- and multispectral remote sensing datasets is essential to investigate the mineralogy and the physical and chemical properties of a planetary surface. The mineralogy and the average composition of the surface of airless bodies observed today in our Solar System are the result of formation and evolution processes that occurred over geologic timescales. In the last decade, our knowledge on planetary surfaces improved considerably thanks to the datasets acquired by remote sensing instruments, such as cameras and spectrometers on board several space missions. Here, we show issues and potentialities of different hyper- and multispectral datasets aimed to the production and analysis of mineralogical and spectral indices maps of airless bodies of the Solar System. This work is funded by the European Union's Horizon 2020 research grant agreement No 776276- PLANMAP and by the Italian Space Agency (ASI) within the SIMBIO-SYS project (ASI-INAF agreement 2017-47-H.0).

Studies, e.g. [1,2], reveal that the South-Pole Aitken (SPA) basin is unique, particularly because it is the deepest basin on the Moon and might be expected to expose the lunar mantle [3]. The innermost part of SPA is rich in high Ca-pyroxenes, except for some central crater peaks, where low Ca-pyroxenes dominate. No extensive olivine-rich areas are observed, implying a mantle rich in low Ca-pyroxenes instead of olivine [1, 3, 4]. Furthermore, thorium anomalies have been discovered in two craters within Aitken basin [5]. Here, we focus on the spectral analysis of one of the most interesting impact crater inside SPA, the Apollo basin. Recently, [6] published a detailed geological map of the area surrounding Apollo basin (35.69°S, 151.48°W; D~524 km), using morphology, stratigraphy, crater size-frequency distribution measurements, and Clementine spectral data to define the unit. Our work explores data from the M3 imaging spectrometer onboard Chandrayaan-1 [7] for this region. These analyses are part of the PLANMAP project, and the integration of the spectroscopical information with the results from [6] will permit to produce highly informative geological maps of the Moon [8]. This work is funded by the European Union's Horizon 2020 research grant agreement No 776276- PLANMAP. References [1] Ohtake, M. et al., 2014, GRL. [2] Moriarty, D.P. et al., 2018, JGR. [3] Dhingra, D., 2018, Geosciences. [4] Melosh, H. J., et al., 2017, Geology. [5] Lawrence, D.J. et al., 2000, JGR. [6] Ivanov, M.A., 2018, JGR. [7] Pieters et al., 2009, Current Science [8] https://www.planmap.eu/

Studies, e.g. (Ohtake et al., 2014, Moriarty and Pieters, 2018), reveal that the South-Pole Aitken (SPA) basin is unique, particularly because it is the deepest basin on the Moon and might be expected to expose the lunar mantle (Dhingra et al., 2018). The innermost part of SPA is rich in high Ca-pyroxenes, except for some central crater peaks, where low Ca-pyroxenes dominate. No extensive olivine-rich areas are observed, implying a mantle rich in low Ca-pyroxenes instead of olivine (Ohtake et al., 2014, Dhingra et al., 2018, Melosh et al., 2018). Furthermore, thorium anomalies have been discovered in two craters within Aitken basin (Lawrence et al., 2000). Here, we focus on the spectral analysis of one of the most interesting impact crater inside SPA, the Apollo basin. Recently, Ivanov et al., (2018) published a detailed geological map of the area surrounding Apollo basin (35.69°S, 151.48°W; D~524 km), using morphology, stratigraphy, crater size- frequency distribution measurements, and Clementine spectral data to define the unit. Our work explores data from the M3 imaging spectrometer onboard Chandrayaan-1 (Pieters et al., 2009) for this region. A preliminary analysis of Apollo basin emphasizes a spectral variability between the smooth terrains within the floor and rest of the crater. The smooth terrains appear darker and show a clear compositional variation with respect to the surroundings regions, indicating the presence of other mineralogical phases mixed with pyronexes, and/or a different geological context. These study is part of the PLANMAP project, and the integration of the spectroscopical information with the results from Ivanov, et al., (2018) will permit to produce highly informative geological maps of the Moon (https://www.planmap.eu/). This work is funded by the European Union's Horizon 2020 research grant agreement No 776276- PLANMAP. References [1] Ohtake, M. et al., 2014. Geologic structure generated by large-impact basin formation observed at the South Pole-Aitken basin on the Moon. Geophysical ...

H05 Hokusai (22.5°N–65°N, 0°–90°E) is one of the northern quadrangles of Mercury [1, 2]. It is characterized by different features, and includes several morpho-stratigraphic units. Smooth plains is the most widespread, covering ~43% of the entire quadrangle, followed by fresh crater material (~17%) and intercrater plains (~10%). The remaining part of the quadrangle contains intermediate plains (7%), degraded crater material (9%) and heavily degraded material (8%) [1]. Other morpho-stratigraphic units, such as smooth and hummocky crater floor material, account for a few percent [1]. Furthermore, this quadrangle includes part of the Hokusai ray system, the largest example on Mercury, and several pyroclastic deposits, including Nathair Facula, one of the highest-reflectance features observed on the planet, located at 480 km NE of Rachmaninoff crater [3, 4]. Spectral analysis based on specific spectral parameters represents a suitable approach to investigate compositional variations. We observed different spectral behavior among large parts of the morpho-stratigraphic units and surface features mapped by [1]. In particular, the units that show the highest spectral variability are the intermediate plains, smooth plains and fresh crater material, together with pyroclastic deposits and crater rays. Such a result indicates spectral variation related to the different units with implications for the geological processes on Mercury's surface. This work is funded by the European Union's Horizon 2020 research grant agreement No 776276- PLANMAP and by the Italian Space Agency (ASI) within the SIMBIO-SYS project (ASI-INAF agreement 2017-47-H.0). References [1] Wright et al., 2018, LPSC 2018 [2] https://planetarynames.wr.usgs.gov/Page/mercuryQuadMap [3] Rothery, D. et al., 2018 Oxford Research Encyclopedia of Planetary Science. Ed. [4] Procter, L. et al., 2010, Science 329.