Search Publications
Geomorphological Evidence for Shallow Ice in the Southern Hemisphere of Mars
McEwen, A. S.; Viola, D.
The localized loss of near-surface excess ice on Mars by sublimation (and perhaps melting) can produce thermokarstic collapse features such as expanded craters and scalloped depressions, which can be indicators of the preservation of shallow ice. We demonstrate this by identifying High Resolution Imaging Science Experiment images containing expand…
MGS-TES Spectra Suggest a Basaltic Component in the Regolith of Phobos
Glotch, Timothy D.; Edwards, Christopher S.; Yesiltas, Mehmet +5 more
The origins of the Martian moons Phobos and Deimos have been the subjects of considerable debate. Visible and near-infrared spectra of these bodies are dark and nearly featureless, with red slopes of varying degrees. These spectra are generally consistent with those of carbonaceous asteroids, leading to the hypothesis that Phobos and Deimos are ca…
UV Dayglow Variability on Mars: Simulation With a Global Climate Model and Comparison With SPICAM/MEx Data
Forget, F.; Montmessin, F.; Chaufray, J. -Y. +4 more
A model able to simulate the CO Cameron bands and the CO2+ UV doublet, two of the most prominent UV emissions in the Martian dayside, has been incorporated into a Mars global climate model. The model self-consistently quantifies the effects of atmospheric variability on the simulated dayglow for the first time. Comparison of …
Thermal Stability of Water Ice in Ceres' Craters: The Case of Juling Crater
Raponi, A.; Tosi, F.; De Sanctis, M. C. +4 more
Ice thermal stability on the surface of the dwarf planet Ceres is an important issue linked to the Herschel observations of water vapor around Ceres. One of these surficial ice deposits is located within the 20-km crater Juling (35°S, 168°E). The study of water ice exposure in this specific crater is particularly interesting because it has been ob…
Modeling the Hydrological Cycle in the Atmosphere of Mars: Influence of a Bimodal Size Distribution of Aerosol Nucleation Particles
Medvedev, Alexander S.; Fedorova, Anna A.; Hartogh, Paul +3 more
We present a new implementation of the hydrological cycle scheme into a general circulation model of the Martian atmosphere. The model includes a semi-Lagrangian transport scheme for water vapor and ice and accounts for microphysics of phase transitions between them. The hydrological scheme includes processes of saturation, nucleation, particle gr…
Geology of Hebes Chasma, Mars: 1. Structure, Stratigraphy, and Mineralogy of the Interior Layered Deposits
Flahaut, Jessica; Hauber, Ernst; Fueten, Frank +2 more
Hebes Chasma is an 8-km deep, 126 by 314 km, isolated basin that is partially filled with massive deposits of water-altered strata called interior layered deposits (ILDs). By analyzing the ILD's structure, stratigraphy, and mineralogy, a depositional history of Hebes Chasma is interpreted. Three distinct ILD units were found and are informally ref…
A Seasonally Recurrent Annular Cyclone in Mars Northern Latitudes and Observations of a Companion Vortex
Gondet, B.; Forget, F.; Hueso, R. +12 more
We study a seasonally recurrent cyclone and related cloud phenomena observed on Mars at Ls 120°, latitude 60°N, and longitude 90°W from images obtained with cameras in different spacecraft between 1995 and 2018. A remarkable double cyclone formed in 2012 and we present a detailed study of its dynamics using images from Mars Express and …
The Far-UV Albedo of Europa From HST Observations
Hendrix, A. R.; Saur, J.; Roth, L. +3 more
We present an analysis of Europa's far-UV spectral albedo using observations during the 1999-2015 time period made by the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. Disk-integrated observations show that the far-UV spectrum in the 130 to 170-nm range is relatively flat or slightly blue (increasing albedo with decreasing wa…
The Search for Active Marsquakes Using Subpixel Coregistration and Correlation: Best Practice and First Results
Grindrod, Peter M.; Hollingsworth, James; Ayoub, Francois +1 more
The state of seismic activity on Mars is currently unknown. On Earth, coseismic displacement has been observed using visible wavelength images and subpixel coregistration and correlation techniques. We apply this method to Mars with the COSI-Corr (Co-registration of Optically Sensed Images and Correlation) software package using High-Resolution Im…