Equatorial Layered Deposits in Arabia Terra, Mars: Facies and process variability

We investigated the equatorial layered deposits (ELDs) of Arabia Terra, Mars, in Firsoff crater and on the adjacent plateau. We produced a detailed geological map that included a survey of the relative stratigraphic relations and crater count dating. We reconstructed the geometry of the layered deposits and inferred some compositional constraints. ELDs drape and onlap the plateau materials of late Noachian age, while they are unconformably covered by early and middle Amazonian units. ELDs show the presence of polyhydrated sulfates. The bulge morphology of the Firsoff crater ELDs appears to be largely depositional. The ELDs on the plateau display a sheet-drape geometry. ELDs show different characteristics between the crater and the plateau occurrences. In the crater they consist of mounds made of breccia sometimes displaying an apical pit laterally grading into a light-toned layered unit disrupted in a meter-scale polygonal pattern. These units are commonly associated with fissure ridges suggestive of subsurface sources. We interpret the ELDs inside the craters as spring deposits, originated by fl uid upwelling through the pathways likely provided by the fractures related to the crater formations, and debouching at the surface through the fi ssure ridges and the mounds, leading to evaporite precipitation. On the plateau, ELDs consist of rare mounds, fl atlying deposits, and cross-bedded dune fields. We interpret these mounds as possible smaller spring deposits, the fl at-lying deposits as playa deposits, and the cross-bedded dune fi elds as aeolian deposits. Groundwater fluctuations appear to be the major factor controlling ELD deposition

Image equalisation using an external brightness reference

After more than ten years in orbit at Mars, the coverage from the High Resolution Stereo Camera (HRSC) on the European Space Agency’s Mars Express is sufficient to begin constructing mosaic products on a global scale. We describe our systematic processing procedure and, in particular, the technique used to bring images affected by atmospheric dust into visual consistency with the mosaic. We outline how the same method is used to produce a relative colour mosaic which shows local colour differences. We demonstrate the results and show that the techniques may also be applied to images from other orbital cameras

Characterisation of Potential Landing Sites for the European Space Agency's Lunar Lander Project

This article describes the characterization activities of the landing sites currently envisaged for the Lunar Lander mission of the European Space Agency. These sites have been identified in the South Pole Region (-85{\deg} to -90{\deg} latitude) based on favourable illumination conditions, which make it possible to have a long-duration mission with conventional power and thermal control subsystems, capable of enduring relatively short periods of darkness (in the order of tens of hours), instead of utilising Radioisotope Heating Units. The illumination conditions are simulated at the potential landing sites based on topographic data from the Lunar Orbiter Laser Altimeter (LOLA), using three independent tools. Risk assessment of the identified sites is also being performed through independent studies. Long baseline slopes are assessed based on LOLA, while craters and boulders are detected both visually and using computer tools in Lunar Reconnaissance Orbiter Camera (LROC) images, down to a size of less than 2 m, and size-frequency distributions are generated. Shadow hazards are also assessed via LROC images. The preliminary results show that areas with quasi-continuous illumination of several months exist, but their size is small (few hundred metres); the duration of the illumination period drops quickly to less than one month outside the areas, and some areas present gaps with short illumination periods. Concerning hazard distributions, 50 m slopes are found to be shallow (few degrees) based on LOLA, whereas at the scale of the lander footprint (~5 m) they are mostly dominated by craters, expected to be mature (from geological context) and shallow (~11{\deg}). The preliminary conclusion is that the environment at the prospective landing sites is within the capabilities of the Lander design

Life cycle of a planetary body definition for scientific analysis

Something as seemingly simple as defining the size of a planetary body is a critical first step required to support the creation of all mapping products and resulting scientific analysis. The life cycle in defining the body size is evolved from the initial Earth-based observations, then refined using acquired data from planetary missions, published in the peer-reviewed literature and adopted by standards- setting working groups, integrated into various libraries and applications, and finally made available for the creation of derived cartographic data products. Here we expose these steps to help users understand the benefits for using standardized definitions to enable data usability and interoperability by looking at the definition for the moon Enceladus

Facilitating Reuse of Planetary Spatial Research Data - Conceptualizing an Open Map Repository as Part of a Planetary Research Data Infrastructure

In recent decades, the research community has been dealing with a growing amount and variety of new research data and derived research information. While primary research data, as derived from instruments, are commonly well maintained, derived research data might not always share the same fate. Scientific studies, resulting in further derived data, what we will call here as research data, does not often share the same attention. Fortunately, in the planetary sciences, most primary research data are commonly freely accessible for researchers to use, while research results have commonly not been re-inserted into the research cycle and a discussion about the process has only recently been initiated but there are not concrete methods or efforts to maintain this derived research data. We here discuss the requirements and needs in the planetary sciences to develop and coordinate a platform for research data and develop this idea using planetary cartographic products as an example of a higher-level research product that undergoes various development stages across different organizational levels. We here will visit the current practice and provide a number of scenarios showing how such a research-data life-cycle could look like in the field of planetary research. In order to develop a conceptual framework, experience from established terrestrial research-data frameworks and spatial data infrastructures are integrated into the discussion

Towards a concept for a Planetary Science Data Library based on a Spatial Data Infrastructure Model

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