Weathering and erosion of the polar layered deposits on Mars

The Martial polar layered deposits are widely believed to be composed of water ice and silicates, but the relative amount of each component is unknown. The conventional wisdom among Mars researchers is that the deposits were formed by periodic variations in the deposition of dust and ice caused by climate changes over the last 10 to 100 million years. It is assumed here that water ice is an important constituent of the layered deposits, that the deposits were formed by eolian processes, and that the origin and evolution of the north and south polar deposits were similar. Weathering of the layered deposits by sublimation of water ice can account for the geologic relationships in the polar regions. The nonvolatile components of the layered deposits appears to consist mainly of bright red dust, with small amounts of dark dust or sand. Dark dust, perhaps similar to the magnetic material found at the Viking Lander sites, may perferentially form filamentary residue particles upon weathering of the deposits. Once eroded, these particles may saltate to form the dark dunes found in both polar regions

Application of photometric analyses for interpretation of Mars-Mariner VI and VII imagery

The application of radiometric analysis in the interpretation of Mariner 6 and 7 imagery is investigated and illustrated. The following types of problems were felt could be addressed using this imagery: (1) evaluation of local reflectivity changes; (2) augmentation of geological mapping; (3) discrimination of atmospheric phenomena; and (4) investigation of polar cap structure

McIDAS-eXplorer: A version of McIDAS for planetary applications

McIDAS-eXplorer is a set of software tools developed for analysis of planetary data published by the Planetary Data System on CD-ROM's. It is built upon McIDAS-X, an environment which has been in use nearly two decades now for earth weather satellite data applications in research and routine operations. The environment allows convenient access, navigation, analysis, display, and animation of planetary data by utilizing the full calibration data accompanying the planetary data. Support currently exists for Voyager images of the giant planets and their satellites; Magellan radar images (F-MIDR and C-MIDR's, global map products (GxDR's), and altimetry data (ARCDR's)); Galileo SSI images of the earth, moon, and Venus; Viking Mars images and MDIM's as well as most earth based telescopic images of solar system objects (FITS). The NAIF/JPL SPICE kernels are used for image navigation when available. For data without the SPICE kernels (such as the bulk of the Voyager Jupiter and Saturn imagery and Pioneer Orbiter images of Venus), tools based on NAIF toolkit allow the user to navigate the images interactively. Multiple navigation types can be attached to a given image (e.g., for ring navigation and planet navigation in the same image). Tools are available to perform common image processing tasks such as digital filtering, cartographic mapping, map overlays, and data extraction. It is also possible to have different planetary radii for an object such as Venus which requires a different radius for the surface and for the cloud level. A graphical user interface based on Tel-Tk scripting language is provided (UNIX only at present) for using the environment and also to provide on-line help. It is possible for end users to add applications of their own to the environment at any time

High-Resolution Topography and Albedo of the South Polar Layered Deposits on Mars

Using a new photoclinometric technique with high-resolution Mariner 9 images, maximum slopes of 10°–20° are found to occur on an exposure of layered deposits within the south polar residual cap of Mars. Stereophotogrammetry is used to constrain the photoclinometric solutions, which resolve layer thicknesses of 100–300 m. Albedo variations are correlated with slope, indicating that frost is present on level areas. There is evidence for temporal changes in frost distribution in the 7 days (4° of L_S) between the two images used in this study. The magnitude of the slopes derived here and consideration of the stability of water ice at the surface of the layered deposits strongly suggest the presence of a competent weathering rind. The weathered surface may be composed of dark filamentary sublimation residue particles that protect the underlying ice from solar heating. This hypothesis is consistent with previous studies of the regional color and albedo of the layered deposits, which indicate that the deposits are slightly darker and less red than the bright dust that mantles much of the south polar region. Furthermore, the proposed weathering mechanism provides a plausible source of dark, saltating material for the Martian polar dune fields

A bibliography of planetary geology principal investigators and their associates, 1980-1981

A compilation of selected bibliographic data (600 citations) specifically relating to recent publications submitted by principal investigators and their associates on planetary geology is given

Reports of planetary geology program, 1976 - 1977

One hundred seventeen investigations undertaken in the NASA Planetary Geology Program in 1976-1977 are reported in abstract form. Topics discussed include solar system formation; planetary interiors; planetary evolution; asteroids, comets and moons; cratering; volcanic, eolian, fluvial and mass wasting processes; volatiles and the Martian regolith; mapping; and instrument development and techniques. An author index is provided

Photometric Investigations of Lunar Landing Sites and Silicic Regions using LRO Narrow Angle Camera Images

The reflectance properties of a planetary surface are related to the physical and compositional properties of that body. Photometry is a powerful method for determining differences in composition and regolith structure, and photometric data from orbital images coupled with soil sample data can greatly enhance our understanding of the regolith properties of our nearest neighbor, the Moon. At the time of writing, the United States has no operating missions on the Moon and no future plans to send robots or humans to study our nearest neighbor, so we must rely on remote sensing data to provide us with information about the lunar surface. This dissertation uses photometric studies of high-resolution Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) images and Hapke photometric modeling to understand the behavior and composition of lunar soil at spacecraft landing sites and areas of non-mare volcanism on the Moon. This work has implications for future mission planning and implementation, including landing site selection, landing safety, and sampling strategies. Topics include: i) the effects of rocket exhaust on lunar soil reflectance properties at the Apollo, Luna, and Surveyor landing sites, ii) photometric analysis of the recent Chang\u27e-3 landing site and comparison of reflectance alterations with those of older landing sites, and iii) compositional variations at regions of non-mare volcanism using NAC photometry and spectral analysis of glassy analog materials. Rocket exhaust from the Apollo, Luna, and Surveyor descent engines disturbed the regolith at their landing sites, causing the soil to become more reflective. These surface alterations, which we call blast zones , are still evident in NAC images, and I use photometry and Hapke modeling to show that the increase in reflectance was caused by smoothing, destruction of fine-scale surface structure (i.e., fairy-castle structure), and possibly redistribution of fine particles. The recent Chinese Chang\u27e-3 spacecraft also disturbed the soil at its landing site in the same fashion, and I show that the reflectance changes and area of disturbance are in family with those of older landing sites, indicating reflectance changes have not changed on the order of decades. I determine the relationship between lander mass and blast zone area and use this to make predictions of the area of soil disturbance for future missions. Finally, using photometric methods optimized from landing site studies, I place compositional constraints on areas of non-mare and intrusive volcanism and confirm that these areas exhibit a range of evolved silicic compositions (dacite, andesite, and rhyolite) and pyroclastic deposits, and should be considered as scientific targets for future landed sample-return missions

PLANETCAM-UPV/EHU: A dual channel lucky imaging camera for solar system studies. Performance, Calibration and Scientific applications.

200 p.PlanetCam-UPV/EHU es una cámara astronómica `lucky imaging¿ diseñada para la obtención de imágenes de alta resolución de objetos del Sistema Solar, principalmente como apoyo a la investigación científica en dinámica atmosférica y estudios de estructura vertical de nubes en las atmósferas planetarias. El instrumento trabaja simultáneamente en dos canales, cada uno con su propio detector y filtros del interés en el rango Visible (0.38 - 1 ¿m) e infrarrojo cercano SWIR (1 - 1.7 ¿m). El instrumento contiene varios filtros seleccionados para imágenes de color y una amplia serie de filtros correspondientes a las bandas de absorción de metano y CO2, así como sus longitudes de onda adyacentes, todos ellos seleccionados por su interés en los estudios planetarios. El objetivo principal dentro del alcance de esta tesis ha sido caracterizar el funcionamiento radiométrico y astronómico de PlanetCam, así como su calibración en reflectividad absoluta, proporcionando valores de la reflectividad absoluta de Júpiter y de Saturno a lo largo de cuatro años de observación. Por otra parte, se ha realizado una serie de estudios científicos de los principales planetas del Sistema Solar en términos de dinámica atmosférica así como un modelo de transferencia radiativa para el análisis de la estructura vertical de la atmósfera de Júpiter