相关论文: Thermal Segregation and Reddening in Europa's Doub…
Desert mirages were simulated in the laboratory by heating a flat surface of sand. This showed that a boundary layer of air, of only a few millimeters immediately covering a heated surface has nearly the same thickness over a wide range of…
As a long-term energy source, tidal heating in subsurface oceans of icy satellites can influence their thermal, rotational, and orbital evolution, and the sustainability of oceans. We present a new theoretical treatment for tidal heating in…
Thermal measurements constrain the physical properties of icy satellite surfaces, including grain size, porosity, and regolith structure. On Europa, analyses of the Galileo Photopolarimeter-Radiometer (PPR) dataset revealed thermal inertia…
Europa's interior is expected to be divided into the metallic core, rocky mantle and hydrosphere based on the moment of inertia factor estimated from gravity field measurements. Specifically, the thickness of the outermost water layer is…
One of the clearest but unresolved questions for Europa is the thickness of its icy shell. Europa's surface is resplendent with geological features that bear on this question, and ultimately on its interior, geological history, and…
Europa's icy surface likely overlies an ocean, but the ice thickness is not known. Here we model the temporal growth of a Europan shell of pure ice subject to varying ice-ocean heat fluxes, ice rheologies, and internal heating rates. Both…
The surface of Europa experiences a competition between thermally-induced crystallization and radiation-induced amorphization processes, leading to changes of its crystalline structure. The non-linear crystallization and…
We present best-fit values of porosity -- and the corresponding effective thermal inertiae -- determined from three different depths in Europa's near-subsurface (~1-20 cm). The porosity of the upper ~20 cm of Europa's subsurface varies…
Evidence for plumes of water on Europa has previously been found using the Hubble Space Telescope (HST) using two different observing techniques. Roth et al. (2014) found line emission from the dissociation products of water. Sparks et al.…
The surfaces of some icy moons, such as Jupiter's moon Europa, are heavily bombarded by energetic particles that can alter the surface materials and affect the composition of its exosphere. Detection of CO2 on Europa's surface indicate that…
Theoretical models of protoplanetary disks including stellar irradiation often show a spontaneous amplification of scale height perturbations, produced by the enhanced absorption of starlight in enlarged regions. In turn, such regions cast…
Europa's surface composition and evidence for cryovolcanic activity can provide insight into the properties and composition of the subsurface ocean, allowing the evaluation of its potential habitability. One promising avenue for revealing…
Segregation by thermal diffusion of an intruder immersed in a sheared granular gas is analyzed from the (inelastic) Boltzmann equation. Segregation is induced by the presence of a temperature gradient orthogonal to the shear flow plane and…
The circulation in Europa's ocean determines the degree of thermal, mechanical and chemical coupling between the ice shell and the silicate mantle. Using global direct numerical simulations, we investigate the effect of heterogeneous tidal…
During the summer melt period, ponds form on the surface of Arctic sea ice as it melts, with important consequences for ice evolution and marine ecology. Due to the ice-albedo feedback, these melt ponds experience uneven heat absorption,…
The surface of Europa is geologically young and shows signs of current activity. Studying it from a photometric point of view gives us insight on its physical state. We used a collection of 57 images from Voyager's Imaging Science System…
Europa's surface exhibits morphological features which, associated with a low crater density, might be interpreted to have formed as a result of recent cryovolcanic activity. In particular, the morphology of smooth deposits covering parts…
Physical processing of Europan surface water ice by thermal relaxation, charged particle bombardment, and possible cryovolcanic activity can alter the percentage of the crystalline form of water ice compared to that of the amorphous form of…
The composition of Europa's trailing hemisphere reflects the combined influences of endogenous geologic resurfacing and exogenous sulfur radiolysis. Using spatially resolved visible-wavelength spectra of Europa obtained with the Hubble…
Our knowledge about the physical processes determining the activity of comets were mainly influenced by several extremely successful space missions, the predictions of theoretical models and the results of laboratory experiments. However,…