相关论文: A patchy CO$_2$ exosphere on Ganymede revealed by …
Ganymede's atmosphere is produced by radiative interactions with its surface, sourced by the Sun and the Jovian plasma. The sputtered and thermally desorbed molecules are tracked in our Exospheric Global Model (EGM), a 3-D parallelized…
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.…
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…
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…
Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (i.e., elements heavier than helium, also called…
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…
CO$_2$ is an important, stable, and abundant molecule in the Universe, but it is very difficult to detect because it has no observable pure rotational transitions. The unique sensitivity and resolution of the James Webb Space Telescope…
The detection of ozone (O3) in the surface ices of Ganymede, Jupiters largest moon, and of the Saturnian moons Rhea and Dione, has motivated several studies on the route of formation of this species. Previous studies have successfully…
The surfaces of icy moons are primarily composed of water ice that can be mixed with other compounds, such as carbon dioxide. The carbon dioxide (CO$_2)$ stretching fundamental band observed on Europa and Ganymede appears to be a…
Currently, the analysis of transmission spectra is the most successful technique to probe the chemical composition of exoplanet atmospheres. But the accuracy of these measurements is constrained by observational limitations and the…
Transmission spectroscopy of exoplanets has the potential to provide precise measurements of atmospheric chemical abundances, in particular of hot Jupiters whose large sizes and high temperatures make them conducive to such observations. To…
The UVS instrument on the Juno mission records far-ultraviolet reflected sunlight from Jupiter. These spectra are sensitive to the abundances of chemical species in the upper atmosphere and to the distribution of the stratospheric haze…
We propose a mechanism for the oxidation of gaseous CO into CO2 occurring on the surface mineral hematite (Fe2O3(s)) in hot, CO2-rich planetary atmospheres, such as Venus. This mechanism is likely to constitute an important source of…
Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H2O), methane (CH4), carbon dioxide (CO2), and carbon monoxide (CO) have been detected in two hot Jupiters. These…
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…
Jupiter's moon Europa has a subsurface ocean, the chemistry of which is largely unknown. Carbon dioxide (CO$_2$) has previously been detected on the surface of Europa, but it was not possible to determine whether it originated from…
H$_3^+$ emission is the dominant cooling mechanism in Jupiter's thermosphere and a useful probe of temperature and ion densities. The H$_3^+$ ion is predicted to form in the thermospheres of close-in `hot Jupiters' where its emission would…
We consider super-Earth sized planets which have a water mass fraction that is large enough to form an external mantle composed of high pressure water ice polymorphs and that lack a substantial H/He atmosphere. We consider such planets in…
Sub-Neptune exoplanets frequently exhibit muted transmission spectra, with GJ 1214 b being the most prominent example. Following years of intense observing campaigns yielding featureless planetary spectra, recent observations with JWST…
Surface-bound exospheres facilitate volatile migration across the surfaces of nearly airless bodies. However, such transport requires that the body can both form and retain an exosphere. To form a sublimation exosphere requires the surface…