Surface information derived from exospheric measurements at planetary bodies complements surface mapping provided by dedicated imagers, offering critical insights into surface release processes, dynamics of various interactions within the planetary environment, erosion, space weathering, and planetary evolution. This study explores a method for deriving the elemental composition of Mercury’s regolith from in-situ measurements of its neutral exosphere using deep neural networks (DNNs). We present a supervised feed-forward DNN architecture—a network of fully-connected neural layers, the so-called multilayer perceptron (MLP). This network takes exospheric densities and proton precipitation fluxes, derived from a simulated orbital run through Mercury’s exosphere, as inputs and predicts the chemical elements of the surface regolith below. It serves as an estimator for the surface-exosphere interaction and the processes leading to exosphere formation, including micrometeoroid impact vaporization, ion sputtering, photon-stimulated desorption, and thermal desorption. Extensive training and testing campaigns demonstrate the MLP DNN’s ability to accurately predict and reconstruct surface composition maps from simulated exospheric measurements. These results not only affirm the algorithm’s robustness but also illuminate its extensive capabilities in handling complex data sets for the creation of estimators for modeled exospheric generation. Furthermore, the tests reveal substantial potential for further development, suggesting that this method could significantly enhance the analysis of complex surface-exosphere interactions and reduce uncertainties in planetary exospheres models. This work anticipates the analysis of data from the SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) instrument package aboard the BepiColombo Mercury Planetary Orbiter, with its nominal phase starting in 2026.

The electromagnetic coupling between the Galilean satellites at Jupiter and the planetary ionosphere generates an auroral footprint, whose ultimate source is the relative velocity between the moons and the corotating magnetospheric plasma. The footprint can be detected in the infrared L band (3.3-3.6 microns) by the Jovian InfraRed Auroral Mapper (JIRAM) onboard the Juno spacecraft, which can observe the footprint position with high precision. Here, we report the JIRAM data acquired since August 27th 2016 until May 23rd 2022, corresponding to the first 42 orbits of Juno. The dataset is used to compute the average position of the footprint tracks of Io, Europa and Ganymede. The result of the present analysis can help to test the reliability of magnetic field models, to calibrate ground-based observations and to highlight episodes of variability in the footprint positions, which in turn can point out specific conditions of the Jovian magnetospheric environment.

In Ceres dwarf planet, a portion of a prior ocean at shallow depth may still exist today as localized reservoirs. In this work, we constrained chemical and geophysical properties of initial aqueous fluids, characterizing the reservoirs, located under two selected craters: Kupalo and Juling. At first, we applied FREZCHEM code to simulate brines’ freezing processes, under different values of initial total pressure in which the starting solutions have cooled to precipitate the solids characterizing these craters. Then, we compared the results with our chemical equilibria calculations to understand the equilibrium state for each precipitated mineral, during the cooling process, related to the activities of solutes and the ionic strength of solutions. Decreasing temperature caused the precipitations of carbonates (thermodynamically favored), followed by the formation of sulphates and, later, of Cl-bearing salts from more saline brines. Solids precipitation feeds cooling process, changing the velocity/density ratios of aqueous solutions that would have arrived at surface erupting with a velocity of ⁓8·10-5 m/s. An excess of pressure in the reservoirs could have supported an intrusion of briny materials to surface, and, in our simulations, we suggest that sodium-salts formation is pressure-dependent. This supports the hypothesis that different “cooling chambers”, at different pressure conditions, may exist under the craters. Moreover, beneath Kupalo, at specific pressure condition, some kinetics-dependent molecules could form, suggesting that aqueous solutions plausibly were affected by kinetics slower than the nearby Juling.

In this work we present the detection of CH4 and H3+ emissions in the atmosphere of Jupiter as two well separated layers, located, respectively, at a tangent altitudes of about 200 km and 500-600 km above the 1-bar level. We studied the vertical distribution of the two species retrieving their Volume Mixing Ratio (VMR) and temperature simultaneously or allowing only one quantity to vary. From this analysis, it is not possible to firmly conclude if the observed H3+ and CH4 features are due to an increase of their VMR or rather to variations of the temperature of the two molecules. However, our retrieval indicates that CH4 is in non-Local Thermal Equilibrium (non-LTE) condition, considering that the retrieved temperature values at about 300 km, where the maximum CH4 concentration lies, is always about 100 K higher than the Galileo measurements. We suggest that vertically propagating waves is the most likely explanation for the observed VMR and temperature variations in the JIRAM (Jovian InfraRed Auroral Mapper) data. Other possible phenomena could explain the observed evidences, for example a dynamical activity driving chemical species from lower layers towards the upper atmosphere, like the advection-diffusion processes responsible for the enhancement observed by Juno/MWR (MicroWave Radiometer), or soft electrons precipitation, although a better modeling is required to confirm these hypothesis. The characterization of CH4 and H3+ species, simultaneously observed by JIRAM, offers the opportunity for better constraining the atmospheric models of Jupiter and understanding the planetary formation.