A5102007722- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Astrophysics and Star Formation Studies
- Space Exploration and Technology
- Methane Hydrates and Related Phenomena
- Scientific Research and Discoveries
- Particle physics theoretical and experimental studies
- Spacecraft and Cryogenic Technologies
- Ion-surface interactions and analysis
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- nanoparticles nucleation surface interactions
- Quantum Chromodynamics and Particle Interactions
- Space Science and Extraterrestrial Life
- Chemical Synthesis and Characterization
- Laser-induced spectroscopy and plasma
- Atmospheric chemistry and aerosols
- Nuclear Physics and Applications
- Optical measurement and interference techniques
- Freezing and Crystallization Processes
- Ophthalmology and Eye Disorders
- Geology and Paleoclimatology Research
- Conservation Techniques and Studies
- Cryospheric studies and observations
University of Bern
2011-2024
Jet Propulsion Laboratory
2020-2022
Heidelberg University
2016
Swiss Federal Nuclear Safety Inspectorate
1984
Since OSIRIS started acquiring high-resolution observations of the surface nucleus comet 67P/Churyumov-Gerasimenko, over one hundred meter-sized bright spots have been identified in numerous types geomorphologic regions, but mostly located areas receiving low insolation. The are either clustered, debris fields close to decameter-high cliffs, or isolated without structural relation surrounding terrain. They can be up ten times brighter than average at visible wavelengths and display a...
We have measured the bidirectional reflectance of analogs dry, wet, and frozen Martian soils over a wide range phase angles in visible spectral range. All samples were produced from two geologic samples: standard JSC Mars‐1 soil simulant Hawaiian basaltic sand. In first step, experiments conducted with dry to investigate effects surface texture. Comparisons results independently obtained by different teams similar showed satisfying reproducibility photometric measurements as well noticeable...
Abstract Permanently shadowed regions at the poles of Moon and Mercury have been pointed out as candidates for hosting water ice their surface. We measured in laboratory visible near infrared spectral range (VIS‐NIR) bidirectional reflectance intimate mixtures JSC‐1AF lunar simulant different concentrations, particle sizes, measurement geometries. The nonlinearity between amount mixture can be reproduced to some extent by mixing formulas standard models, particular, those Hapke Hiroi, which...
To detect signs of life by remote sensing on objects our Solar System and exoplanets, the characterization light scattered surface material could complement possible clues given atmospheric composition. We reviewed reflectance spectra a broad selection major biomolecules that constitute terrestrial carbon-based from 0.4 to 2.4 μm, we discuss their detectability through spectral windows. Biomolecule features in near-infrared (0.8–2.4 μm) will likely be obscured water some gases. The visible...
We present the results of photometric and spectrophotometric properties 67P/Churyumov-Gerasimenko nucleus derived with OSIRIS instrument during closest fly-by over comet, which took place on 14 th February 2015 at a distance {\~} 6 km from surface. Several images covering 0{\deg}-33{\deg} phase angle range were acquired, spatial resolution achieved was 11 cm/pxl. The flown-by region is located big lobe near borders Ash, Apis Imhotep regions. Our analysis shows that this features local...
The polarimetry of the light scattered by planetary surfaces is a powerful tool to provide constraints on their microstructure. To improve interpretation polarimetric data from icy surfaces, we have developed POLarimeter for ICE Samples (POLICES) complementing measurement facilities Ice Laboratory at University Bern. new setup uses high precision Stokes polarimeter measure degree polarization in visible moderate phase angles (from 1.5 30{\deg}). We present photometric and curves measured...
High-resolution OSIRIS/Rosetta images of 67P/Churyumov–Gerasimenko acquired on the night run 2016 April 9–10 show, at large scale, an opposition effect (OE) spot sweeping across Imhotep as phase angle ranges from 0° to 17°. In this work, we fitted curve whole surface imaged well three particular features using both linear–exponential and Hapke models. These encompass different types spectral behaviour: a circular mesa, one venous structure assemblage bright spots, going red blue colours....
Abstract Ion formation from alkali halide solids caused by the irradiation of high power (some 10 8 W/ cm 2 ) pulsed lasers is investigated means time-of-flight mass spectrometry (LAMMA®). It shown that ions are formed directly solid state, several uppermost atomic layers being involved; gas phase interactions negligible. The ion rates, however, in-compatible with assumption a quasiequilibrium transition, but should be explained in terms non-adiabatic rate processes discussed some detail....
Particle-particle and particle-gas processes significantly impact planetary precursors such as dust aggregates planetesimals. We investigate gas permeability ($\kappa$) in 12 granular samples, mimicking planetesimal regoliths. Using parabolic flights, this study assesses how gravitational compression -- lack thereof influences permeation, impacting the equilibrium state of low-gravity objects. Transitioning between micro- hyper-gravity induces sedimentation dynamics, revealing collective...
The field of planetary system formation relies extensively on our understanding the aerodynamic interaction between gas and dust in protoplanetary disks. Of particular importance are mechanisms triggering fluid instabilities clumping particles into aggregates, their subsequent inclusion planetesimals. We introduce timed Epstein multi-pressure vessel at low accelerations, which is an experimental apparatus for study particle dynamics rarefied under micro-gravity conditions. This facility...
We use an existing laboratory facility for space hardware calibration in vacuum to study the impact of energetic ions on water ice. The experiment is intended simulate conditions surface Jupiter's icy moons. present first results ion sputtering a sample porous ice, including experimental sulphur confirm theoretical predictions and extrapolations from previous experiments obtained at different angles non-porous