The analysis of Martian meteorites is a key research to understand the mineralogical composition of Mars. However, they suffer different types of alteration due to the environment where they fall on Earth. These differences should be identified in order to characterize correctly the original Martian compounds. Most of the meteorites found on Earth are collected in Antarctica where the environmental conditions are such that, in general and based on many previous investigations, produce fewer alterations compared with other terrestrial environments such as hot deserts. In this study, the weathering alterations of minerals from the MIL 090030 Martian Nakhlite found in Antarctica were analyzed to determine which minerals are formed by Antarctic environmental conditions. It was confirmed that the south-polar region environment can contaminate Martian meteorites and, in this study, several minerals like halite, nitratine and niter, were detected as weathering alteration products that have not been referenced in the literature before.

Until recently, the influence of basal liquid water on the evolution of buried glaciers in Mars' mid latitudes was assumed to be negligible because the latter stages of Mars' Amazonian period (3 Ga to present) have long been thought to have been similarly cold and dry to today. Recent identifications of several landforms interpreted as eskers associated with these young (100s Ma) glaciers calls this assumption into doubt. They indicate basal melting (at least locally and transiently) of their parent glaciers. Although rare, they demonstrate a more complex mid-to-late Amazonian environment than was previously understood. Here, we discuss several open questions posed by the existence of glacier-linked eskers on Mars, including on their global-scale abundance and distribution, the drivers and dynamics of melting and drainage, and the fate of meltwater upon reaching the ice margin. Such questions provide rich opportunities for collaboration between the Mars and Earth cryosphere research communities.

We report detailed chemical and isotopic data from a subglacial siliceous deposit on andesitic bedrock recently exposed by glacier retreat. Whereas a single, <1 μm, Si-rich layer covers the highly polished bedrock on the up-glacier (stoss) surfaces, distinct, lithified deposits commonly occur at the lee of small bedrock protuberances, on a scale <0.1 meter. The deposit is millimeters in thickness and consists of laminae tens to hundreds microns thick that differ from one another in color, rock-fragment abundance and chemical composition. Ca-rich laminae that are sufficiently enriched in uranium (~2–50 ppm) to permit U-series isotopic analysis suggest that the subglacial deposit formed 10–20 ka, much earlier than previously assumed. We conclude that (1) the siliceous deposit persisted for at least 10 000 years despite the intervening erosion and weathering, (2) distinct episodes of formation due to significant changes in hydrology and water chemistry are recorded in the deposit, and (3) a siliceous slurry may have existed at the ice-rock interface and influenced the local friction. This work reinforces earlier findings that subglacial chemical deposits can form and persist on geologic time scales and may have implications for the role of the cryosphere in the Earth's geochemical cycles and climate system.

The Autonomous Pinger Unit (APU) is an electro-thermal drill with acoustic instrumentation developed for the project EnEx-RANGE in view of a future space mission for the sub-surface exploration of Saturn's moon Enceladus. A main goal is the development of navigation technology for an acoustic guidance system allowing maneuvering a probe through glacial ice. In total 13 APUs were built and tested in terrestrial analog scenarios on alpine glaciers. The APUs form a spatially distributed network that defines a system of reference for the navigation of the maneuverable probe to a point of interest. The APUs have a novel melting head, slow control systems, and a modern system-on-chip (SoC) module that controls the probe and processes the recorded data. The APUs use acoustic emitters and receivers to measure the transit time of acoustic signals between them, allowing for the position reconstruction of all APUs by trilateration. Several auxiliary sensors monitor the internal state of the probe and assist the position estimation. With this instrumentation, the APUs have the ability of dynamically optimizing themselves within the network by changing their position. This paper gives an overview of the developed APU hardware and presents performance results from the field tests.

The Martian mid-latitudes contain numerous small water-ice deposits, collectively termed viscous flow features (VFFs). The shape and topography of the deposits contain information on their past flow history and formation process. In order to access this information, it is imperative to get information on their deformational properties. Here we use a high-resolution digital topography map and ice-penetrating radar data in combination with an inverse method to constrain the deformational properties of a lobate debris apron, a class of VFF, in the southern hemisphere of Mars. We find that while the creep parameter and accumulation rates are not well constrained in absolute values, their ratio is robust. We also find that the creep exponent is most likely n ≤ 3.

There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.