ИСТИНА

The last decades have been marked by increasing evidence for cold trapped volatiles, including water, at the lunar poles (e.g., Keller et al., 2016). Lunar volatiles are targets of interest both as scientific repositories and for exploration purposes. Orbital measurements reveal an enhancement in hydrogen at both poles, which is interpreted as evidence for surface or subsurface water ice (e.g., Feldman et al., 1998). In addition, recent Moon Mineralogy Mapper (M3) data reveal hydroxylation of the lunar surface (Pieters et al., 2009a). Determining the exact nature, extent and origin of the hydroxyl/water and other volatiles at and near the surface at the poles required in situ analyses via lander or rover missions. Several upcoming projects and missions are targeting these chemical compounds such as the Luna-25 (also referred to as Luna-Glob) and Luna-27 Russian missions. The present study focuses on potential volatile-rich and science-rich targets with the landing area of the Luna-Glob mission, with the aim to determine and characterize all potential landing areas. Potential landing sites for Luna-Glob must meet the following engineering and science criteria (Mitrofanov et al., 2016):  The latitude and longitude of the supposed landing site must be between 65-85°S and 0-60°E;  The landing ellipse dimensions must be 15×30 km (spread in longitudinal direction);  Surface slopes in landing site must not be greater than 7° on a 2.5 m scale;  The mean illumination within the landing area must be maximal;  The Earth visibility (for radio communication) within the landing area must be maximal;  The hydrogen abundance as estimated from orbit must be maximal. In order to select terrains that meet these conditions (+ present eventual additional science benefits), da-tasets and derived products from various instruments were collected and co-analyzed into a Geographic Infor-mation System (GIS). Our data collection includes:  LOLA DEM at 60 m/pixel (Neumann et al., 2016) and derived slope map,  LOLA-based average illumination and Earth visibility maps (Mazarico et al., 2011),  LPNS and LEND H abundance maps (Elphic et al., 2007, Mitrofanov et al., 2010),  Diviner average, minimum, and maximum temperature maps (Paige et al., 2010),  USGS geologic map (Fortezzo et al., 2013, renovation of the Wilhelms and McCauley 1971 maps),  Elemental and petrologic maps derived from a polynomial regression that relates LP GRS elemental abundances (Lawrence et al., 1998) to M3 (Pieters et al., 2009b) spectral parameters (see details on the method in Wöhler et al., 2014; Rommel et al., 2016). The resulting maps include elemental abundances of Ca, Al, Fe, Mg, Ti and O at 0.05 degrees per pixel and a petrologic map constructed using the meth-od of Berezhnoy et al. (2005), which is a RGB composite of a mare basalt endmember (18 wt% Fe, 6.5 wt% Mg, red channel), a Mg-rich rock endmember (4 wt% Fe, 13 wt% Mg, green channel, e.g. troctolite or orthopyroxene-rich norite) and feldspathic rock (0.5 wt% Fe, 1 wt% Mg, blue channel, especially fer-roan anorthosite) (Rommel et al., 2016). Twelve ellipses have already been proposed by the Russian Space Research Institute team (Mitrofanov et al., 2016). By eliminating all areas of slope > 7° and illumination < 40% (blackened on Fig. 1), we propose six additional candidate ellipses located in the remaining terrains and being characterized by high H abundance with both the LPNS and LEND instrument data (Cyan outlines on Fig. 1a). These ellipses are labelled as 13-18 and are all located north of -70° in latitude. Zonal statistics were then performed to compute mean values and standard deviations for the elevation, slope, illumination, Earth visibility, H abundance, minimum, maximum and average Diviner temperature, composition and age of each of the 18 proposed ellipses (Table 1). There are discrepancies between the H abundances as estimated from the LPNS and LEND dataset (e.g., ellipse 8 show high values with the LEND data but low values with the LPNS data), but some ellipses (e.g., 16, 17, 18) have high H abundance values ac-cording to both instruments data. All the ellipses fall within the same average temperature range as estimated from the Diviner polar maps, however these values will be further improved with thermal modelling calculation. It is important to notice than the composition of terrains is very homogeneous within the investigated latitude/longitude range even though the ages of terrains vary (Fig. 1b). Terrains within the region of investigation are likely composed of anorthositic material. Candidate Landing Sites Ranking: Based on the computed statistics, we suggest to discard ellipses 7, 10, 12 (high slopes), 3, 9 (low illumination), 4 (low Earth visibility), 5 and 8 (low H abundance). Ellipses 1, 13 and 16 appear to be more suitable landing sites and should be considered of higher priority. Ellipse 1 presents slightly better illumination conditions but lower H abundances and higher Diviner average and maximum temperature than ellipses 13 and 16 (suggesting that less volatile species might be present). Ellipses 2, 6, 15, 17, and 18 are retained with intermediate priority (Fig. 1b). Future work will include high resolution scientific characterization of the three preferred ellipses (e.g., estimate of surface temperatures from thermal modelling as described in Wöhler et al. (2016), age estimation from crater counts). This work is partially supported by joint RFBR-DFG grant No. 15-52-12369 / WO 1800/7-1. J. Flahaut is supported by a CNES postdoctoral fellowship. Keller J. W. et al. (2016), Icarus, 273, 2-24. Feldman W. C. et al. (1998), Science, 281, 1496-1500. Pieters C. M. et al. (2009a), Science, 326, 568-572. Mitrofanov I. et al. (2016), ELS abstract. Neumann G. A. (2016), LROLOLA RDR DPSIS, available on the PDS. Mazarico E. et al. (2011), Icarus, 211, 1066-1081. Elphic R. C. et al. (2007), JGR 34, 13. Mitrofanov I. et al. (2010), 330,483-486. Paige D. A. et al. (2010), 330, 479-482. Fortezzo C. M. et al. (2013), 44, 2114. Wilhelms D. E. and J. F. McCauley (1971), USGS. Lawrence D. J. et al. (1998), Science, 281, 1484-1489. Pieters C. M. et al. (2009b), Science, 96, 500-50. Wöhler C. et al. (2014), Icarus 235, 86-122. Rommel D. et al. (2016), ELS abstract. Berezhnoy A. A. et al. (2005), Plan-et. Space Sci. 53, 1097–1108. Wöhler C. et al. (2016), submitted to Icarus.