Search Publications
Boulder abundances and size-frequency distributions on Oxia Planum-Mars: Scientific implications for the 2020 ESA ExoMars rover
Quantin, Cathy; Pajola, Maurizio; Carter, John +4 more
This paper presents the abundances and the size-frequency distributions (SFD) of boulders identified on a sector of the prime landing site for the ExoMars 2020 rover, in Oxia Planum region. By means of a HiRISE image, boulders ≥ 1.75 m across have been identified and subdivided according to the two main Oxia Planum geological units: the Noachian c…
Venus cloud-tracked and doppler velocimetry winds from CFHT/ESPaDOnS and Venus Express/VIRTIS in April 2014
Widemann, Thomas; Donati, Jean-François; Machado, Pedro +3 more
We present new coordinated observations and measurements of the wind amplitude and its variability at Venus cloud-tops based on the two complementary techniques of Ground-based Doppler velocimetry (Widemann et al., 2007, 2008; Machado et al., 2012, 2014) and cloud-tracked winds using ESA Venus Express/ VIRTIS-M imaging at 0.38 µm (Drossart e…
Jupiter's auroral-related stratospheric heating and chemistry I: Analysis of Voyager-IRIS and Cassini-CIRS spectra
Fletcher, L. N.; Irwin, P. G. J.; Orton, G. S. +4 more
Auroral processes are evident in Jupiter's polar atmosphere over a large range in wavelength (X-ray to radio). In particular, previous observations in the mid-infrared (5-15 µm) have shown enhanced emission from CH4, C2H2 and C2H4 and further stratospheric hydrocarbon species in spatial …
Analysis and modeling of remote observations of the martian hydrogen exosphere
Bertaux, J. -L.; Chaufray, J. -Y.; Clarke, J. T. +2 more
Past observations of the martian exosphere have given a wide range of values for the mean temperature and number density of the hydrogen population that occupies this uppermost layer. More recently, observations by HST and MEX have found large variations over short timescales exhibited by this layer, which have been attributed to seasonal effects.…
Interannual and seasonal changes in the south seasonal polar cap of Mars: Observations from MY 28-31 using MARCI
James, P. B.; Cantor, B. A.; Calvin, W. M.
The Mars Color Imager (MARCI) camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars Years (MY) and over the southern summer. We present the first analysis of this data for the southern seasonal cap evolution observed in MY 28, 29, 30…
Dynamics of aspherical dust grains in a cometary atmosphere: I. axially symmetric grains in a spherically symmetric atmosphere
Fulle, M.; Della Corte, V.; Rotundi, A. +3 more
In-situ measurements of individual dust grain parameters in the immediate vicinity of a cometary nucleus are being carried by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. For the interpretations of these observational data, a model of dust grain motion as realistic as possible is requested. In particular, the results of the Stardust …
Polygonal ridge networks on Mars: Diversity of morphologies and the special case of the Eastern Medusae Fossae Formation
Head, James W.; Kerber, Laura; Dickson, James L. +1 more
Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morpholog…
Coogoon Valles, western Arabia Terra: Hydrological evolution of a complex Martian channel system
de Pablo, Miguel Ángel; Molina, Antonio; López, Iván +3 more
Coogoon Valles is an intricate fluvial system, and its main channel was formed during the Noachian period through the erosion of the clay-bearing basement of the Western Arabia Terra. This region is characterized by a thinner crust compared to the rest of the highlands and by the occurrence of massive phyllosilicate-bearing materials. The origin o…
Structure and density of Callisto's atmosphere from a fluid-kinetic model of its ionosphere: Comparison with Hubble Space Telescope and Galileo observations
Saur, Joachim; Strobel, Darrell F.; Hartkorn, Oliver
We develop a model of the ionospheric electron population of Jupiter's moon Callisto using a prescribed neutral atmosphere composed of O2, CO2 and H2O. A kinetic description of ionospheric suprathermal electrons coupled with a fluid description of ionospheric thermal electrons is well suited to jointly analyze and …
A possibly universal red chromophore for modeling color variations on Jupiter
Baines, K. H.; Sromovsky, L. A.; Carlson, R. W. +1 more
A new laboratory-generated chemical compound made from photodissociated ammonia (NH3) molecules reacting with acetylene (C2H2) was suggested as a possible coloring agent for Jupiter's Great Red Spot (GRS) by Carlson et al. (2016, Icarus 274, 106-115). Baines et al. (2016, Icarus, submitted) showed that the GRS spec…