Space Research & Planetary Sciences Division Web Site

Planetary Imaging Group Web Site

Figure 1. [a] Polygonal patterns observed on the floor of Mawrth Vallis in Mars using the HiRISE camera. [b] Similar polygonal patterns on a smaller scale that have been observed by the Opportunity Rover on Mars. [c] Locations of Possible desiccation cracks on Mars based on a number of studies carried out at the University of Bern.
Figure 2. Comet 67P by Rosetta's OSIRIS narrow-angle camera on 3 August 2014. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

My research interests are Martian geology/geomorphology, but also extend to small bodies and moons. In regards to Mars, the scope of my research encompasses glacial/periglacial, volcanic and hydrological processes. The main theme of my research is polygonal crack patterns that are potentially of desiccation origin. Surface polygonal patterns are common on the surface of Mars. These patterns attain various shapes and variable sizes, which can vary from cm- to km-sized patterns (Fig. 1). Historically, most of the surface patterns, in particular those observed in the higher latitudes, were regarded as periglacial features that evolve through thermal contraction. However, the High Resolution Science Experiment (HiRISE) onboard MRO allowed us to look at the Martian surface at unprecedented sub-meter (0.25–0.5m/pixel) resolutions. Taking advantage of such spatial resolutions, numerous surface cracking patterns were observed on the surface, particularly in the southern hemisphere, which differ from the conventional morphology and size-scale of thermal contraction polygons on Mars. In addition, these features do not show a significant latitudinal dependence but instead a regional preference for locations that could have harbored liquid water more than 3 billion years ago. During the past 4 years, I have led a number of collaborative research projects to assess the role of desiccation in Mars’ early (Noachian) history by carrying out global observations of candidate features in impact craters, chloride-bearing and phyllosilicate-bearing terrains. In addition, I have constructed analytical and numerical models to better understand the desiccation mechanism and differentiate it from thermal contraction, carrying out field studies in analogue sites and setting up lab experiments in Berne to analyze different simulants.

 

I have also carried out additional projects that include investigating the Tharsis region (a major volcanic complex) using gamma-ray spectroscopy, assessing volcanic sites with potential for ancient hydrothermal activity and investigating the Argyre basin for signs of past hydrological and current glacial/periglacial activity (Fig. 5). My current activities and ongoing collaborations include assessing the hydrological history of Mars’ major basins: Hellas and Argyre, investigating Apollinaris Mon’s giant fan deposits and assessing the periglacial history of Argyre and Utopia, and studying the morphology  of comet 67P (Churyumov-Gerasimenko) as a participating scientist in the European Rosetta mission.  

Finally, I have taken part, and have been actively involved in numerous space missions, both European- and US-managed since 2007, which includes collaborating on the Gamma-Ray spectrometer experiment onboard the Mars Odyssey and The Phoenix lander mission. I am currently a participating scientist in the OSIRIS camera onboard the Rosetta cometary orbiter, a team member of the HiRISE camera onboard MRO where I am involved in target selection, and a CO-I for the CaSSIS high-resolution color and stereo camera, which is planned to fly on the ExoMars Thermal gas Orbiter in early 2016.

Planetary Imaging Group Web Site

Space Research & Planetary Sciences Division Web Site