Raphael Marschall
A5015335406- Astro and Planetary Science
- Planetary Science and Exploration
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- Isotope Analysis in Ecology
- Astronomical and nuclear sciences
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
- High-pressure geophysics and materials
- Atmospheric Ozone and Climate
- Radioactive contamination and transfer
- Nuclear physics research studies
- Space Satellite Systems and Control
- Methane Hydrates and Related Phenomena
- Radioactive Decay and Measurement Techniques
- Geomagnetism and Paleomagnetism Studies
- Geological and Geochemical Analysis
- Gamma-ray bursts and supernovae
- Atomic and Subatomic Physics Research
- Space exploration and regulation
- Medical Imaging Techniques and Applications
- Fusion and Plasma Physics Studies
- Molecular Spectroscopy and Structure
- Chemical Reactions and Isotopes
Centre National de la Recherche Scientifique
2022-2024
Observatoire de la Côte d’Azur
2022-2024
Southwest Research Institute
2019-2022
International Space Science Institute
2018-2020
Laboratory for Atmospheric and Space Physics
2020
University of Bern
2015-2019
John Wiley & Sons (United States)
2015
Charles River Laboratories (Netherlands)
2015
Aims. The OSIRIS camera onboard the Rosetta spacecraft has been acquiring images of comet 67P/Churyumov-Gerasimenko (67P)'s nucleus at spatial resolutions down to ~0.17 m/px ever since Aug. 2014. These have yielded unprecedented insight into morphological diversity comet's surface. This paper presents an overview regional morphology 67P.
Context. We present an investigation of the surface properties areas on nucleus comet 67P/Churyumov-Gerasimenko.
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...
Aims. The OSIRIS camera on board the Rosetta spacecraft has been acquiring images of comet 67P/Churyumov-Gerasimenko (67P)’s nucleus since August 2014. Starting in May 2015, southern hemisphere gradually became illuminated and was imaged for first time. Here we present regional morphology hemisphere, which serves as a companion to an earlier paper that presented northern hemisphere.
Abstract This chapter reviews the estimates of dust-to-gas and refractory-to-ice mass ratios derived from Rosetta measurements in lost materials nucleus 67P/Churyumov-Gerasimenko, respectively. First, by instruments are described, as well relevant characteristics 67P. The complex picture activity 67P, with its extreme North-South seasonal asymmetry, is presented. Individual then presented compared, showing wide ranges plausible values. ’s wealth information suggests that ratio made cometary...
Abstract The origins of the giant planet satellites are debated, with scenarios including formation from a protoplanetary disk, sequential assembly massive rings, and recent accretion after major satellite–satellite collisions. Here, we test their predictions by simulating outer solar system bombardment calculating oldest surface ages on each moon. Our crater production model assumes projectiles originated primordial Kuiper Belt (PKB) that experienced substantial changes collisional...
Asteroids with diameters less than about 5 km have complex histories because they are small enough for radiative torques, YORP, to be a notable factor in their evolution. (152830) Dinkinesh is asteroid orbiting the Sun near inner edge of Main Asteroid Belt heliocentric semimajor axis 2.19 AU; its S type spectrum typical bodies this part Belt. Here we report observations by Lucy spacecraft as it passed within 431 Dinkinesh. revealed Dinkinesh, which has an effective diameter only $\sim$720 m,...
Abstract The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) experiment onboard the Rosetta spacecraft currently orbiting comet 67P/Churyumov‐Gerasimenko has yielded unprecedented views of a comet's nucleus. We present here first ever observations meter‐scale fractures on surface comet. Some these form polygonal networks. an initial assessment their morphology, topology, regional distribution. Fractures are ubiquitous Furthermore, they occur in various settings show...
Context. This paper describes the initial modelling of gas and dust data acquired in August September 2014 from European Space Agency's Rosetta spacecraft when it was close proximity to nucleus comet 67P/Churyumov-Gerasimenko.
In this work, we present results that simultaneously constrain the dust size distribution, dust-to-gas ratio, fraction of re-deposition, and total mass production rates for comet 67P/Churyumov-Gerasimenko. We use a 3D Direct Simulation Monte Carlo (DSMC) gas dynamics code to simulate inner coma duration Rosetta mission. The model is constrained by ROSINA/COPS data. Further, different epochs using including drag nucleus' gravity. Using advanced scattering properties these are used produce...
Abstract Planetesimals are compact astrophysical objects roughly 1–1000 km in size, massive enough to be held together by gravity. They can grow accreting material become full-size planets. themselves thought form complex physical processes from small grains protoplanetary disks. The streaming instability (SI) model states that millimeter/centimeter-sized particles (pebbles) aerodynamically collected into self-gravitating clouds then directly collapse planetesimals. Here we analyze ATHENA...
Abstract The tumultuous early era of outer solar system evolution culminated when Neptune migrated across the primordial Kuiper Belt (PKB) and triggered a dynamical instability among giant planets. This event led to ejection ∼99.9% PKB (here called destabilized population), heavy bombardment planet satellites, capture Jupiter’s Trojans. While this scenario has been widely tested using models, there have fewer investigations into how PKB, its population, Trojans experienced collisional...
Abstract We report the detection of 239 trans-Neptunian objects discovered through ongoing New Horizons survey for distant minor bodies being performed with Hyper Suprime-Cam mosaic imager on Subaru Telescope. These were in images acquired either r 2 or recently commissioned EB- gri filter using shift and stack routines. Due to extremely high stellar density search region downstream spacecraft, new machine learning techniques had be developed manage false-positive rate bogus candidates...
The previously defined regions on the nucleus of comet 67P/Churyumov-Gerasimenko have been mapped back onto 3D SHAP7 model (Preusker et al., 2017). resulting regional definition is therefore self-consistent with boundaries that are well in 3 dimensions. facets belonging to each region provided as supplementary material. shape has then used assess inhomogeneity surface morphology within individual regions. Several show diverse morphology. We propose sub-division these into clearly...
Aims . This paper focuses on how insolation affects the nucleus of comet 67P/Churyumov-Gerasimenko over its current orbit. We aim to better understand thermal environment nucleus, in particular surface temperature variations, erosion, relationship with topography, and interior for location volatile species (H 2 O CO ). Methods have developed two models calculate subsurface temperatures 67P 6.45-year The first model, high resolution (300 000 facets), calculates temperatures, taking shadows...
Comets, asteroids, and other small bodies are thought to be remnants of the original planetesimal population Solar System. As such, their physical, chemical, isotopic properties hold crucial details on how where they formed evolved. Yet, placing precise constraints formation region these has been challenging. Data from spacecraft missions have a particularly high potential addressing question origin visited bodies. ESA's Rosetta mission comet 67P/Churyumov-Gerasimenko returned data for two...
Context. This paper describes the modelling of gas and dust data acquired in period August to October 2014 from European Space Agency's Rosetta spacecraft when it was close proximity nucleus comet 67P/Churyumov-Gerasimenko.
The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) onboard the European Space Agency's Rosetta spacecraft acquired images of comet 67P/Churyumov–Gerasimenko (67P) its surrounding dust coma starting from May 2014 until September 2016. In this paper we present methods results analysis OSIRIS regarding outflow in innermost 67P. aim is to determine global behaviour place constraints on physical processes affecting particles inner coma. We study region right above nucleus...
Abstract Comet 67P/Churyumov‐Gerasimenko displays a pronounced hemispherical dichotomy in surface morphology, where the southern hemisphere exhibits more erosional features than northern due to receiving much greater solar radiation. Consequently, it is generally assumed that particles are ejected from through sublimation and significant fraction eventually descends as airfall, covering terrains. To investigate this south‐to‐north material transfer during comet's perihelion passage, we used...
Context. The formation and evolution of protoplanetary disks remains elusive. We have numerous astronomical observations young stellar objects different ages with their envelopes and/or disks. Moreover, in the last decade, there has been tremendous progress numerical simulations star disk formation. New use realistic equations state for gas treat interaction matter magnetic field full set nonideal magnetohydrodynamic (MHD) equations. However, it is still not fully clear how a forms whether...
Abstract The origin of the Jupiter Trojan asteroids has long been a mystery. Dynamically, population, which is considerably smaller than main asteroid belt, librates around Jupiter’s stable L4 and L5 Lagrange points, 60 deg ahead behind Jupiter. It thought that these bodies were captured into orbits early in solar system history, but any capture mechanism must also explain why Trojans have an excited inclination distribution, with some objects reaching inclinations 35°. themselves,...
We have used the latest available shape model for gas and dust simulations of inner coma comet 67P/Churyumov-Gerasimenko period around May 2015 (equinox). compare results from a purely insolation-driven with complementary set observations made by ROSINA, VIRTIS, MIRO, OSIRIS within same period. The include - first time inverted MIRO measurements density, temperature bulk velocity to constrain model. comparisons show that, as in November 2014 (Marschall et al., 2016), activity does not...