Search Publications

Comet 67P/CG: Influence of the sublimation coefficient on the temperature and outgassing

Markiewicz, Wojciech J.; Kossacki, Konrad J.

The sublimation rate of ice is commonly calculated using simple Hertz-Knudsen formula. This formula is derived from the kinetic theory of gases and ignores microphysical processes determining the actual sublimation rate. The microphysical processes can be accounted for by including in the Herz-Knudsen equation a temperature dependent sublimation c…

The influence of recent major crater impacts on the surrounding surfaces of (21) Lutetia

Jorda, L.; Kührt, E.; Thomas, N. +4 more

We present 3-D simulations of impacts into Asteroid 21 Lutetia, the subject of a fly-by by the European Space Agency’s Rosetta mission to Comet 67P/Churyumov-Gerasimenko. Using a 3-D shape model of the asteroid, impacts of sizes sufficient to reproduce the observed craters in Lutetia’s North Polar Crater Cluster (NPCC) as observed by the OSIRIS ex…

The vertical structure of the F ring of Saturn from ring-plane crossings

Nicholson, Philip D.; Scharringhausen, Britt R.

We present a photometric model of the rings of Saturn which includes the main rings and an F ring, inclined to the main rings, with a Gaussian vertical profile of optical depth. This model reproduces the asymmetry in brightness between the east and west ansae of the rings of Saturn that was observed by the Hubble Space Telescope (HST) within a few…

Martian atmospheric particulate spectral end-members recovery from PFS and IRIS data

Palomba, Ernesto; Zinzi, Angelo; Helbert, Jörn +2 more

We present an application of a multivariate analyses technique on data returned by the Planetary Fourier Spectrometer (PFS) instrument on board the ESA’s Mars Express (MEX) spacecraft in order to separate the atmospheric contribution from the observed radiation. We observe that Thermal/Far Infrared spectra returned from Mars, covering almost a who…

Corrigendum to “Titan’s surface and atmosphere from Cassini/VIMS data with updated methane opacity” [Icarus 226 (2013) 470-486]

Le Mouélic, S.; Rodriguez, S.; Lellouch, E. +13 more

The surface composition of Iapetus: Mapping results from Cassini VIMS

Nicholson, Philip D.; Baines, Kevin H.; Buratti, Bonnie J. +11 more

Cassini VIMS has obtained spatially resolved imaging spectroscopy data on numerous satellites of Saturn. A very close fly-by of Iapetus on September 10, 2007 provided the best data on the spectral signature and spatial extent of dark material on Iapetus. This Cassini Rev 49 Iapetus fly-by provided spatially resolved imaging spectroscopy data of th…

Planetary surface dating from crater size-frequency distribution measurements: Spatial randomness and clustering

Platz, T.; Michael, G. G.; Kneissl, T. +1 more

We describe a quantitative procedure to measure the degree of clustering in an observed crater population relative to a series of randomly distributed populations. We split the population by according to crater size to be able to identify clustering at different scales, and find that a clustering analysis based on the mean 2nd-closest neighbour di…

Sulfur chemistry in the middle atmosphere of Venus

Belyaev, Denis A.; Zhang, Xi; Yung, Yuk L. +2 more

Venus Express measurements of the vertical profiles of SO and SO ₂ in the middle atmosphere of Venus provide an opportunity to revisit the sulfur chemistry above the middle cloud tops (∼58 km). A one dimensional photochemistry-diffusion model is used to simulate the behavior of the whole chemical system including oxygen-, hydrogen-, chl…

A photochemical model for the Venus atmosphere at 47-112 km

Krasnopolsky, Vladimir A.

The model is intended to respond to the recent findings in the Venus atmosphere from the Venus Express and ground-based submillimeter and infrared observations. It extends down to 47 km for comparison with the kinetic model for the lower atmosphere (Krasnopolsky, V.A. [2007]. Icarus 191, 25-37) and to use its results as the boundary conditions. Th…

Titan global climate model: A new 3-dimensional version of the IPSL Titan GCM

Charnay, Benjamin; Lebonnois, Sébastien; Rannou, Pascal +1 more

We have developed a new 3-dimensional climate model for Titan’s atmosphere, using the physics of the IPSL Titan 2-dimensional climate model with the current version of the LMDZ General Circulation Model dynamical core. Microphysics and photochemistry are still computed as zonal averages. This GCM covers altitudes from surface to 500 km altitude, w…