Space Weathering on Near-Earth Objects investigated by neutral-particle detection

The ion-sputtering (IS) process is active in many planetary environments in the Solar System where plasma precipitates directly on the surface (for instance, Mercury, Moon, Europa). In particular, solar-wind sputtering is one of the most important agents for the surface erosion of a Near-Earth Object (NEO), acting together with other surface release processes, such as Photon Stimulated Desorption (PSD), Thermal Desorption (TD) and Micrometeoroid Impact Vaporization (MIV). The energy distribution of the IS-released neutrals peaks at a few eVs and extends up to hundreds of eVs. Since all other release processes produce particles of lower energies, the presence of neutral atoms in the energy range above 10 eV and below a few keVs (Sputtered High-Energy Atoms - SHEA) identifies the IS process. SHEA easily escape from the NEO, due to NEO's extremely weak gravity. Detection and analysis of SHEA will give important information on surface-loss processes as well as on surface elemental composition. The investigation of the active release processes, as a function of the external conditions and the NEO surface properties, is crucial for obtaining a clear view of the body's present loss rate as well as for getting clues on its evolution, which depends significantly on space weather. In this work, an attempt to analyze the processes that take place on the surface of these small airless bodies, as a result of their exposure to the space environment, has been realized. For this reason a new space weathering model (Space Weathering on NEO - SPAWN), is presented. Moreover, an instrument concept of a neutral-particle analyzer specifically designed for the measurement of neutral density and the detection of SHEA from a NEO is proposedComment: 36 page

Characterization of the Morphometry of Impact Craters Hosting Polar Deposits in Mercury's North Polar Region

Earth-based radar images dating back two decades show that the floors of some polar craters on Mercury host radar-bright deposits that have been proposed to consist of frozen volatiles. Several hypotheses have been put forth to explain their source, including volcanic outgassing, chemical sputtering, and deposition of exogenous water ice. Calculations show that volatiles are thermally stable in permanently shadowed areas. An earlier study of the depths of north polar craters determined with photoclinometric techniques applied to Mariner 10 images yielded the conclusion that the mean ratio of crater depth d to rim-crest diameter D for craters hosting polar deposits is two-thirds that of the mean ratio for a comparable population of neighboring craters lacking such deposits. This result could be explained by (though doesn't require) the presence of a thick layer of volatiles within the polar deposit-hosting craters. Here we use altimetric profiles and topographic maps obtained by the Mercury Laser Altimeter (MLA) to revisit this analysis. MLA is an instrument on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which has been orbiting Mercury since March 2011. MLA transmits a 1064-nm laser pulse at 8 Hz during MESSENGER's trajectory over Mercury s surface. The MLA illuminates surface areas averaging between 15 m and 100 m in diameter, spaced approx 400 m apart along the spacecraft ground track. The radial precision of individual measurements is <1 m, and the current accuracy with respect to Mercury s center of mass is better than 20 m. As of mid-December 2011, MLA coverage had reached to 15 S and has yielded a comprehensive map of the topography of Mercury s northern hemisphere. The MLA data are used here to quantify the shapes of craters in the north polar region and to avoid the shadowing bias of photoclinometric techniques

The image of Nagorno-Karabakh conflikt in russian TV station Russia Today

Niniejsza praca skupia się na zagadnieniu roli mediów w konfliktach zbrojnych. Tematem przewodnim jest wojna o Górski Karabach pomiędzy Armenią i Azerbejdżanem w 2020 roku. Praca została skonstruowana w taki sposób, aby przybliżyć sens konfliktu o Górski Karabach, pokazać różne jego aspekty oraz określić rolę rosyjskiej narracji medialnej w tym konflikcie. W danej pracy został przedstawiony obraz wojny o Górski Karabach w rosyjskiej stacji telewizyjnej Russia Today. Dokonana została także analiza treści komunikatów umieszczonych na stronie internetowej stacji w celu pokazania w jaki sposób rosyjska narracja medialna przyczynia się do kształtowania opinii i poglądów społeczności międzynarodowej. Szczególna uwaga została przydzielona temu, jak skutecznie Rosja wykorzystuje media w celu szerzenia propagandy oraz wytworzenia akceptacji społecznej dla własnej polityki.This paper focuses on the role of the media in armed conflicts. The leading theme is the 2020 war between Armenia and Azerbaijan over Nagorno-Karabakh. The main focus of the thesis is to show the background of the Nagorno-Karabakh war, and its various aspects and define the role of the Russian media narrative in this conflict. In addition, the paper present the image of the Nagorno-Karabakh war on the Russian TV station "Russia Today". In order to show how the Russian media narrative contributes to shaping the opinions and views of the international community, the content of articles on a station website was analyzed. Particular attention was drawn to how effectively Russia uses the media to spread propaganda and generate public acceptance of its politics