相关论文: Global Modelling of Ganymede's Surface Composition…
Ganymede's surface exhibits great geological diversity, with old dark terrains, expressed through the surface composition, which is known to be dominated by two constituents: H2O-ice and an unidentified darkening agent. In this paper, new…
We present maps of surface composition of Europa's anti-jovian hemisphere acquired using high spatial resolution IFU multi-spectral data from the SPHERE instrument on the Very Large Telescope (0.95 to 1.65$\mu$m) and the NIMS instrument on…
JWST NIRSpec IFU (2.9-5.3 mu) and MIRI MRS (4.9-28.5 mu) observations were performed on both the leading and trailing hemispheres of Ganymede with a spectral resolution of ~2700. Reflectance spectra show signatures of water ice, CO2 and…
Since its first identification on the surface of Ganymede in 1995, molecular oxygen (O2) ice has been at the center of a scientific debate as the surface temperature of the Jovian moon is on average well above the freezing point of O2.…
Ground-based spectroscopy of Ganymede's surface has revealed the surprising presence of dense-phase molecular oxygen (O$_2$) via weak absorptions at visible wavelengths. To date, the state and stability of this O$_2$ at the temperatures and…
The composition of the surface of the Galilean icy moons has been debated since the Galileo mission. Several chemistries have been proposed to explain the composition of the non-icy component of the moon's surfaces, notably, sulphuric acid…
We present thermal observations of Ganymede from the Atacama Large Millimeter Array (ALMA) in 2016-2019 at a spatial resolution of 300-900 km (0.1-0.2'' angular resolution) and frequencies of 97.5, 233, and 343.5 GHz (wavelengths of 3, 1.3,…
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…
In this paper, we model the plasma environment of Ganymede by means of a collisionless test particle simulation. By coupling the outputs from a DSMC simulation of Ganymede's exosphere (i.e. number density profiles of neutral species such as…
The surface of Europa could contain the compositional imprint of a underlying interior ocean, but competing hypotheses differ over whether spectral observations from the Galileo spacecraft show the signature of ocean evaporates or simply…
The Galileo Near Infrared Mapping Spectrometer (NIMS) collected spectra of Europa in the 0.7-5.2 $\mu$m wavelength region, which have been critical to improving our understanding of the surface composition of this moon. However, most of the…
Ganymede's atmosphere is produced by charged particle sputtering and sublimation of its icy surface. Previous far-ultraviolet observations of the O{\small I\,}1356-{\AA} and O{\small I\,}1304-{\AA} oxygen emissions were used to infer…
We report new observations of the spectrum of Ganymede in the spectral range 1160 - 1720 A made with the Space Telescope Imaging Spectrograph (STIS) on HST on 1998 October 30. The observations were undertaken to locate the regions of the…
Geophysical measurements can reveal the structure of icy ocean worlds and cycling of volatiles. The associated density, temperature, sound speed, and electrical conductivity of such worlds thus characterizes their habitability. To explore…
Icy moons orbiting giant planets are often described as airless bodies though they host an exosphere where collisions between neutral species are scarce. In the case of Ganymede, the neutral composition is dominated by $\mathrm{H_2O}$,…
A key feature of the Galilean satellite system is its monotonic decrease in bulk density with distance from Jupiter, indicating an ice mass fraction that is zero in the innermost moon Io, and about half in the outer moons Ganymede and…
We publish the first NIR spectra of grain particulate mixtures of water ice, epsomite, and halite at cryogenic temperatures. Furthermore, we perform a quantitative assessment of the ability of both intimately- and linearly-mixed models to…
We present global, spatially resolved ultraviolet-visible spectra of Callisto obtained with HST/STIS and explore possible compositions of Callisto's surface material. We map the strength of a widespread downturn toward the near-UV and the…
Recent infrared observations at 1.5-4.0 $\mu m$ using large ground-based telescopes have suggested that Cl-bearing salts are likely present on Europa's surface as non-ice materials. The chemical compositions of those Cl-bearing salts are…
Ganymede's aurora are the product of complex interactions between its intrinsic magnetosphere and the surrounding Jovian plasma environment and can be used to derive both atmospheric composition and density. In this study, we analyzed a…