@article{BuergerHayneGundlachetal., author = {B{\"u}rger, Johanna and Hayne, Paul and Gundlach, Bastian and L{\"a}uter, Matthias and Kramer, Tobias and Blum, J{\"u}rgen}, title = {A Microphysical Thermal Model for the Lunar Regolith: Investigating the Latitudinal Dependence of Regolith Properties}, series = {Journal of Geophysical Research: Planets}, volume = {129}, journal = {Journal of Geophysical Research: Planets}, number = {3}, doi = {10.1029/2023JE008152}, abstract = {The microphysical structure of the lunar regolith provides information on the geologic history of the Moon. We used remote sensing measurements of thermal emission and a thermophysical model to determine the microphysical properties of the lunar regolith. We expand upon previous investigations by developing a microphysical thermal model, which more directly simulates regolith properties, such as grain size and volume filling factor. The modeled temperatures are matched with surface temperatures measured by the Diviner Lunar Radiometer Experiment on board the Lunar Reconnaissance Orbiter. The maria and highlands are investigated separately and characterized in the model by a difference in albedo and grain density. We find similar regolith temperatures for both terrains, which can be well described by similar volume filling factor profiles and mean grain sizes obtained from returned Apollo samples. We also investigate a significantly lower thermal conductivity for highlands, which formally also gives a very good solution, but in a parameter range that is well outside the Apollo data. We then study the latitudinal dependence of regolith properties up to ±80° latitude. When assuming constant regolith properties, we find that a variation of the solar incidence-dependent albedo can reduce the initially observed latitudinal gradient between model and Diviner measurements significantly. A better match between measurements and model can be achieved by a variation in intrinsic regolith properties with a decrease in bulk density with increasing latitude. We find that a variation in grain size alone cannot explain the Diviner measurements at higher latitudes.}, language = {en} } @article{HellerFleischmannKramer, author = {Heller, Eric J. and Fleischmann, Ragnar and Kramer, Tobias}, title = {Branched Flow}, abstract = {In many physical situations involving diverse length scales, waves or rays representing them travel through media characterized by spatially smooth, random, modest refractive index variations. "Primary" diffraction (by individual sub-wavelength features) is absent. Eventually the weak refraction leads to imperfect focal "cusps". Much later, a statistical regime characterized by momentum diffusion is manifested. An important intermediate regime is often overlooked, one that is diffusive only in an ensemble sense. Each realization of the ensemble possesses dramatic ray limit structure that guides the waves (in the same sense that ray optics is used to design lens systems). This structure is a universal phenomenon called branched flow. Many important phenomena develop in this intermediate regime. Here we give examples and some of the physics of this emerging field.}, language = {en} } @article{ReimersBiczyskoBruceetal., author = {Reimers, Jeffrey R. and Biczysko, Malgorzata and Bruce, Douglas and Coker, David F. and Frankcombe, Terry J. and Hashimoto, Hideki and Hauer, J{\"u}rgen and Jankowiak, Ryszard and Kramer, Tobias and Linnanto, Juha and Mamedov, Fikret and M{\"u}h, Frank and R{\"a}tsep, Margus and Renger, Thomas and Styring, Stenbj{\"o}rn and Wan, Jian and Wang, Zhuan and Wang-Otomo, Zheng-Yu and Weng, Yu-Xiang and Yang, Chunhong and Zhang, Jian-Ping and Freiberg, Arvi and Krausz, Elmars}, title = {Challenges facing an understanding of the nature of low-energy excited states in photosynthesis}, series = {BBA Bioenergetics}, volume = {1857}, journal = {BBA Bioenergetics}, number = {9}, doi = {10.1016/j.bbabio.2016.06.010}, pages = {1627 -- 1640}, abstract = {While the majority of the photochemical states and pathways related to the biological capture of solar energy are now well understood and provide paradigms for artificial device design, additional low-energy states have been discovered in many systems with obscure origins and significance. However, as low-energy states are naively expected to be critical to function, these observations pose important challenges. A review of known properties of low energy states covering eight photochemical systems, and options for their interpretation, are presented. A concerted experimental and theoretical research strategy is suggested and outlined, this being aimed at providing a fully comprehensive understanding.}, language = {en} } @article{KramerLaeuterHviidetal., author = {Kramer, Tobias and L{\"a}uter, Matthias and Hviid, Stubbe and Jorda, Laurent and Keller, Horst Uwe and K{\"u}hrt, Ekkehard}, title = {Comet 67P/Churyumov-Gerasimenko rotation changes derived from sublimation induced torques}, series = {Astronomy \& Astrophysics}, volume = {630}, journal = {Astronomy \& Astrophysics}, doi = {10.1051/0004-6361/201834349}, pages = {A3}, abstract = {Context. The change of the rotation period and the orientation of the rotation axis of comet 67P/Churyumov-Gerasimenko (67P/C-G) is deducible from images taken by the scientific imaging instruments on-board the Rosetta mission with high precision. Non gravitational forces are a natural explanation for these data. Aims. We describe observed changes for the orientation of the rotation axis and the rotation period of 67P/C-G. For these changes we give an explanation based on a sublimation model with a best-fit for the surface active fraction (model P). Torque effects of periodically changing gas emissions on the surface are considered. Methods. We solve the equation of state for the angular momentum in the inertial and the body- fixed frames and provide an analytic theory of the rotation changes in terms of Fourier coefficients, generally applicable to periodically forced rigid body dynamics. Results. The torque induced changes of the rotation state constrain the physical properties of the surface, the sublimation rate and the local active fraction of the surface. Conclusions. We determine a distribution of the local surface active fraction in agreement with the rotation properties, period and orientation, of 67P/C-G. The torque movement confirms that the sublimation increases faster than the insolation towards perihelion. The derived relatively uniform activity pattern is discussed in terms of related surface features.}, language = {en} } @inproceedings{LaeuterKramerRubinetal., author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {Determination of the ice composition near the surface of comet 67P/Churyumov-Gerasimenko}, series = {Europlanet Science Congress}, booktitle = {Europlanet Science Congress}, doi = {10.5194/epsc2022-826}, pages = {EPSC2022-826}, abstract = {During the apparition of comet 67P/Churyumov-Gerasimenko (67P/C-G) solar irradiation causes varying rates for sublimation of volatile species from the cometary nucleus. Because sublimation processes take place close to the cometary surface, the relative abundance of volatiles in the coma and the ice composition are related to each other. To quantify this relation we assume a model for the expansion of a collisionless gas from the surface into the surrounding space. We use an inverse model approach to relate the in situ measurements of gas densities from the two Rosetta instruments COPS (COmet Pressure Sensor) and DFMS (Double Focusing Mass Spectrometer) at the positions of the spacecraft to the locations of surface gas emissions during the Rosetta mission 2014-2016. We assume the temporally integrated gas emissions to be representative for the ice composition close to the surface. Our analysis shows characteristic differences in the ice compositions between both hemispheres of 67P/C-G. In particular CO2 ice has a reduced abundance on the northern hemisphere. In contrast to the hemispherical differences, the two lobes do not show significant differences in terms of their ice composition.}, language = {en} } @inproceedings{NoackReinefeldKrameretal., author = {Noack, Matthias and Reinefeld, Alexander and Kramer, Tobias and Steinke, Thomas}, title = {DM-HEOM: A Portable and Scalable Solver-Framework for the Hierarchical Equations of Motion}, series = {2018 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW), 19th IEEE Int. Workshop on Parallel and Distributed Scientific and Engineering Computing (PDSEC 2018)}, booktitle = {2018 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW), 19th IEEE Int. Workshop on Parallel and Distributed Scientific and Engineering Computing (PDSEC 2018)}, isbn = {978-1-5386-5555-9}, doi = {10.1109/IPDPSW.2018.00149}, pages = {947 -- 956}, abstract = {Computing the Hierarchical Equations of Motion (HEOM) is by itself a challenging problem, and so is writing portable production code that runs efficiently on a variety of architectures while scaling from PCs to supercomputers. We combined both challenges to push the boundaries of simulating quantum systems, and to evaluate and improve methodologies for scientific software engineering. Our contributions are threefold: We present the first distributed memory implementation of the HEOM method (DM-HEOM), we describe an interdisciplinary development workflow, and we provide guidelines and experiences for designing distributed, performance-portable HPC applications with MPI-3, OpenCL and other state-of-the-art programming models. We evaluated the resulting code on multi- and many-core CPUs as well as GPUs, and demonstrate scalability on a Cray XC40 supercomputer for the PS I molecular light harvesting complex.}, language = {en} } @misc{KramerNoackBaumetal.2017, author = {Kramer, Tobias and Noack, Matthias and Baum, Daniel and Hege, Hans-Christian and Heller, Eric J.}, title = {Dust and gas emission from cometary nuclei: the case of comet 67P/Churyumov-Gerasimenko}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-66338}, year = {2017}, abstract = {Comets display with decreasing solar distance an increased emission of gas and dust particles, leading to the formation of the coma and tail. Spacecraft missions provide insight in the temporal and spatial variations of the dust and gas sources located on the cometary nucleus. For the case of comet 67P/Churyumov-Gerasimenko (67P/C-G), the long-term obser- vations from the Rosetta mission point to a homogeneous dust emission across the entire illuminated surface. Despite the homogeneous initial dis- tribution, a collimation in jet-like structures becomes visible. We propose that this observation is linked directly to the complex shape of the nucleus and projects concave topographical features into the dust coma. To test this hypothesis, we put forward a gas-dust description of 67P/C-G, where gravitational and gas forces are accurately determined from the surface mesh and the rotation of the nucleus is fully incorporated. The emerging jet-like structures persist for a wide range of gas-dust interactions and show a dust velocity dependent bending.}, language = {en} } @article{KramerNoackBaumetal., author = {Kramer, Tobias and Noack, Matthias and Baum, Daniel and Hege, Hans-Christian and Heller, Eric J.}, title = {Dust and gas emission from cometary nuclei: the case of comet 67P/Churyumov-Gerasimenko}, series = {Advances in Physics: X}, volume = {3}, journal = {Advances in Physics: X}, number = {1}, doi = {10.1080/23746149.2017.1404436}, pages = {1404436}, abstract = {Comets display with decreasing solar distance an increased emission of gas and dust particles, leading to the formation of the coma and tail. Spacecraft missions provide insight in the temporal and spatial variations of the dust and gas sources located on the cometary nucleus. For the case of comet 67P/Churyumov-Gerasimenko (67P/C-G), the long-term obser- vations from the Rosetta mission point to a homogeneous dust emission across the entire illuminated surface. Despite the homogeneous initial dis- tribution, a collimation in jet-like structures becomes visible. We propose that this observation is linked directly to the complex shape of the nucleus and projects concave topographical features into the dust coma. To test this hypothesis, we put forward a gas-dust description of 67P/C-G, where gravitational and gas forces are accurately determined from the surface mesh and the rotation of the nucleus is fully incorporated. The emerging jet-like structures persist for a wide range of gas-dust interactions and show a dust velocity dependent bending.}, language = {en} } @article{KramerRodriguez, author = {Kramer, Tobias and Rodr{\´i}guez, Mirta}, title = {Effect of disorder and polarization sequences on two-dimensional spectra of light harvesting complexes}, series = {Photosynthesis Research}, volume = {144}, journal = {Photosynthesis Research}, doi = {10.1007/s11120-019-00699-6}, pages = {147 -- 154}, abstract = {Two-dimensional electronic spectra (2DES) provide unique ways to track the energy transfer dynamics in light-harvesting complexes. The interpretation of the peaks and structures found in experimentally recorded 2DES is often not straightforward, since several processes are imaged simultaneously. The choice of specific pulse polarization sequences helps to disentangle the sometimes convoluted spectra, but brings along other disturbances. We show by detailed theoretical calculations how 2DES of the Fenna-Matthews-Olson complex are affected by rotational and conformational disorder of the chromophores.}, language = {en} } @article{KramerNoackReinefeldetal., author = {Kramer, Tobias and Noack, Matthias and Reinefeld, Alexander and Rodr{\´i}guez, Mirta and Zelinskyi, Yaroslav}, title = {Efficient calculation of open quantum system dynamics and time-resolved spectroscopy with Distributed Memory HEOM (DM-HEOM)}, series = {Journal of Computational Chemistry}, volume = {39}, journal = {Journal of Computational Chemistry}, number = {22}, publisher = {Wiley Periodicals, Inc.}, doi = {doi:10.1002/jcc.25354}, pages = {1779 -- 1794}, abstract = {Time- and frequency resolved optical signals provide insights into the properties of light harvesting molecular complexes, including excitation energies, dipole strengths and orientations, as well as in the exciton energy flow through the complex. The hierarchical equations of motion (HEOM) provide a unifying theory, which allows one to study the combined effects of system-environment dissipation and non-Markovian memory without making restrictive assumptions about weak or strong couplings or separability of vibrational and electronic degrees of freedom. With increasing system size the exact solution of the open quantum system dynamics requires memory and compute resources beyond a single compute node. To overcome this barrier, we developed a scalable variant of HEOM. Our distributed memory HEOM, DM-HEOM, is a universal tool for open quantum system dynamics. It is used to accurately compute all experimentally accessible time- and frequency resolved processes in light harvesting molecular complexes with arbitrary system-environment couplings for a wide range of temperatures and complex sizes.}, language = {en} } @article{KramerNoackReimersetal., author = {Kramer, Tobias and Noack, Matthias and Reimers, Jeffrey R. and Reinefeld, Alexander and Rodr{\´i}guez, Mirta and Yin, Shiwei}, title = {Energy flow in the Photosystem I supercomplex: comparison of approximative theories with DM-HEOM}, series = {Chemical Physics}, volume = {515}, journal = {Chemical Physics}, publisher = {Elsevier B.V.}, doi = {10.1016/j.chemphys.2018.05.028}, pages = {262 -- 271}, abstract = {We analyze the exciton dynamics in PhotosystemI from Thermosynechococcus elongatus using the distributed memory implementation of the hierarchical equation of motion (DM-HEOM) for the 96 Chlorophylls in the monomeric unit. The exciton-system parameters are taken from a first principles calculation. A comparison of the exact results with Foerster rates and Markovian approximations allows one to validate the exciton transfer times within the complex and to identify deviations from approximative theories. We show the optical absorption, linear, and circular dichroism spectra obtained with DM-HEOM and compare them to experimental results.}, language = {en} } @article{NkenkeZachowBenzetal.2004, author = {Nkenke, Emeka and Zachow, Stefan and Benz, Michaela and Maier, Tobias and Veit, Klaus and Kramer, Manuel and Benz, St. and H{\"a}usler, Gerd and Neukam, Friedrich and Lell, Michael}, title = {Fusion of computed tomography data and optical 3D images of the dentition for streak artefact correction in the simulation of orthognathic surgery}, series = {Journal of Dento-Maxillofacial Radiology}, volume = {33}, journal = {Journal of Dento-Maxillofacial Radiology}, doi = {10.1259/dmfr/27071199}, pages = {226 -- 232}, year = {2004}, language = {en} } @inproceedings{LaeuterKramerRubinetal., author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {Gas production for 14 species on comet 67P/Churyumov-Gerasimenko from 2014-2016}, series = {Europlanet Science Congress}, volume = {14}, booktitle = {Europlanet Science Congress}, publisher = {Europlanet Science Congress}, doi = {10.5194/epsc2020-319}, pages = {EPSC2020-319}, abstract = {During a two year period between 2014 and 2016 the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) has been probed by the Rosetta spacecraft. Density data for 14 gas species was recorded with the COmet Pressure Sensor (COPS) and the Double Focusing Mass Spectrometer (DFMS) being two sensors of the ROSINA instrument. The combination with an inverse gas model yields emission rates on each of 3996 surface elements of a surface shape for the cometary nucleus. The temporal evolution of gas production, of relative abundances, and peak productions weeks after perihelion are investigated. Solar irradiation and gas production are in a complex relation revealing features differing for gas species, for mission time, and for the hemispheres of the comet. This characterization of gas composition allows one to correlate 67P/C-G to other solar and interstellar comets, their formation conditions and nucleus properties, see [Bodewits D., et al., 2020 Nature Astronomy].}, language = {en} } @inproceedings{LaeuterKramerRubinetal., author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {Gas production of comet 67P/Churyumov-Gerasimenko reconstructed from DFMS/COPS data}, series = {Europlanet Science Congress}, volume = {12}, booktitle = {Europlanet Science Congress}, publisher = {Europlanet Science Congress}, pages = {EPSC2018-515-1}, abstract = {We reconstruct the temporal evolution of surface emissions for the four major gas species H2O, CO2, CO, and O2 emitted during the 2015 apparition of comet 67P/Churyumov-Gerasimenko (67P/C-G). Measurements from the Double Focusing Mass Spectrometer (DFMS) of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) and the COmet Pressure Sensor (COPS) are used to determine the gas sources on the surface with an inverse gas model for the entire coma. For all species, peak production rates and integrated production rates per orbit are evaluated separately for the northern and the southern hemisphere. Complemented with the total mass production, this allows us to estimate the dust-to-gas ratio of the emitted material.}, language = {en} } @article{KramerNoackBaumetal., author = {Kramer, Tobias and Noack, Matthias and Baum, Daniel and Hege, Hans-Christian and Heller, Eric J.}, title = {Homogeneous dust emission and jet structure near active cometary nuclei: the case of 67P/Churyumov-Gerasimenko}, abstract = {We compute trajectories of dust grains starting from a homogeneous surface activity-profile on a irregularly shaped cometary nucleus. Despite the initially homogeneous dust distribution a collimation in jet-like structures becomes visible. The fine structure is caused by concave topographical features with similar bundles of normal vectors. The model incorporates accurately determined gravitational forces, rotation of the nucleus, and gas-dust interaction. Jet-like dust structures are obtained for a wide range of gas-dust interactions. For the comet 67P/Churyumov-Gerasimenko, we derive the global dust distribution around the nucleus and find several areas of agreement between the homogeneous dust emission model and the Rosetta observation of dust jets, including velocity-dependent bending of trajectories.}, language = {en} } @inproceedings{BuergerHayneGundlachetal., author = {B{\"u}rger, Johanna and Hayne, Paul and Gundlach, Bastian and L{\"a}uter, Matthias and Kramer, Tobias and Blum, J{\"u}rgen}, title = {Investigating the Latitudinal Dependence of Lunar Regolith Properties Using LRO/Diviner Data and a Microphysical Thermal Model}, series = {Bulletin of the AAS}, volume = {55}, booktitle = {Bulletin of the AAS}, number = {8}, abstract = {Regolith is formed through weathering of the local rock by meteorite bombardment, space weathering (Pieters \& Noble, 2016) and thermal erosion (Delbo et al., 2014). In the case of the Moon, the space weathering effects and diurnal temperature variations are reduced towards the poles. The aim of this study is to investigate whether the lunar regolith properties derived from the comparison of regolith temperatures measured by the Diviner radiometer (Paige et al., 2010) on board the Lunar Reconnaissance Orbiter (LRO) with simulated temperatures derived from a microphysical thermal model show a latitudinal dependence. The developed microphysical thermal model expands upon previous models by more directly simulating regolith properties, such as grain radius and volume filling factor.}, language = {en} } @article{HoangGarnierLasueetal., author = {Hoang, Margaux and Garnier, Philippe and Lasue, Jeremie and R{\`e}me, Henri and Capria, Maria Teresa and Altwegg, Kathrin and L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin}, title = {Investigating the Rosetta/RTOF observations of comet 67P/Churyumov-Gerasimenko using a comet nucleus model: Influence of dust mantle and trapped CO}, series = {Astronomy \& Astrophysics}, volume = {638}, journal = {Astronomy \& Astrophysics}, doi = {10.1051/0004-6361/201936655}, pages = {A106}, abstract = {Context. Cometary outgassing is induced by the sublimation of ices and the ejection of dust originating from the nucleus. Therefore measuring the composition and dynamics of the cometary gas provides information concerning the interior composition of the body. Nevertheless, the bulk composition differs from the coma composition, and numerical models are required to simulate the main physical processes induced by the illumination of the icy body. Aims. The objectives of this study are to bring new constraints on the interior composition of the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter 67P) by comparing the results of a thermophysical model applied to the nucleus of 67P and the coma measurements made by the Reflectron-type Time-Of-Flight (RTOF) mass spectrometer. This last is one of the three instruments of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), used during the Rosetta mission. Methods. Using a thermophysical model of the comet nucleus, we studied the evolution of the stratigraphy (position of the sublimation and crystallisation fronts), the temperature of the surface and subsurface, and the dynamics and spatial distribution of the volatiles (H2O, CO2 and CO). We compared them with the in situ measurements from ROSINA/RTOF and an inverse coma model. Results. We observed the evolution of the surface and near surface temperature, and the deepening of sublimation fronts. The thickness of the dust layer covering the surface strongly influences the H2O outgassing but not the more volatiles species. The CO outgassing is highly sensitive to the initial CO/H2O ratio, as well as to the presence of trapped CO in the amorphous ice. Conclusions. The study of the influence of the initial parameters on the computed volatile fluxes and the comparison with ROSINA/RTOF measurements provide a range of values for an initial dust mantle thickness and a range of values for the volatile ratio. These imply the presence of trapped CO. Nevertheless, further studies are required to reproduce the strong change of behaviour observed in RTOF measurements between September 2014 and February 2015.}, language = {en} } @inproceedings{BuergerGundlachBlumetal., author = {B{\"u}rger, Johanna and Gundlach, Bastian and Blum, J{\"u}rgen and Hayne, Paul and L{\"a}uter, Matthias and Kramer, Tobias}, title = {Lunar regolith properties derived from LRO/Diviner data and thermophysical modelling}, series = {Europlanet Science Congress}, booktitle = {Europlanet Science Congress}, doi = {10.5194/epsc2022-92}, pages = {EPSC2022-92}, abstract = {The Moon as our nearest celestial object is one of the most important bodies for space resource exploration and planetary science. However, knowledge of the physical properties of the lunar regolith is required for the exploitation of lunar resources and for understanding the Moon's geologic history. This knowledge comes mainly from Apollo in-situ experiments and returned samples, but the global distribution of these properties is still poorly understood. Remote sensing measurements offer the opportunity to derive properties of unsampled areas with the help of models. In our study, a microphysical thermal model for the lunar regolith was developed and the simulated surface temperatures were compared with thermal emission measurements from the Diviner radiometer on board the Lunar Reconnaissance Orbiter (LRO) to derive regolith properties. This work expands upon previous investigations of lunar regolith properties using Diviner data, by more directly simulating physical properties such as particle size and porosity.}, language = {en} } @article{RodriguezKramer, author = {Rodr{\´i}guez, Mirta and Kramer, Tobias}, title = {Machine Learning of Two-Dimensional Spectroscopic Data}, series = {Chemical Physics}, volume = {520}, journal = {Chemical Physics}, doi = {10.1016/j.chemphys.2019.01.002}, pages = {52 -- 60}, abstract = {Two-dimensional electronic spectroscopy has become one of the main experimental tools for analyzing the dynamics of excitonic energy transfer in large molecular complexes. Simplified theoretical models are usually employed to extract model parameters from the experimental spectral data. Here we show that computationally expensive but exact theoretical methods encoded into a neural network can be used to extract model parameters and infer structural information such as dipole orientation from two dimensional electronic spectra (2DES) or reversely, to produce 2DES from model parameters. We propose to use machine learning as a tool to predict unknown parameters in the models underlying recorded spectra and as a way to encode computationally expensive numerical methods into efficient prediction tools. We showcase the use of a trained neural network to efficiently compute disordered averaged spectra and demonstrate that disorder averaging has non-trivial effects for polarization controlled 2DES.}, language = {en} } @inproceedings{KramerLaeuter, author = {Kramer, Tobias and L{\"a}uter, Matthias}, title = {Matching the activity of comet 67P/Churyumov-Gerasimenko with long-term ground-based astrometry}, series = {Europlanet Science Congress}, volume = {15}, booktitle = {Europlanet Science Congress}, publisher = {Europlanet Science Congress}, doi = {10.5194/epsc2021-337}, pages = {EPSC2021-337}, abstract = {50 years of astrometric data for comet 67P/C-G (orbital period about 6.45 years) provides a unique opportunity to benchmark non-gravitational acceleration models to the in situ measurements of the volatile release performed from the Rosetta rendezvous mission (2014-2016). Taken together, the Earth-bound and in-situ data yields lower fit errors and serves as a test-case for our ability to deduce thermophysical quantities of cometary nuclei from the Earth-bound observations.}, language = {en} }