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The present contribution describes the influence of the properties of potential martian CO 2 cloud particles on their mid-infrared (IR) extinction spectra, with the goal to provide a reference for possible future IR extinction cloud studies on Mars. The focus lies on the understanding of the band shape of the antisymmetric stretching vibration at about 4.3μm. For this purpose, modelling of...
This note tackles the problem of the rotation of Io with the 4-degrees of freedom Poincaré–Hough model. Io is modeled as a 2-layer body, i.e. a triaxial fluid core and a rigid outer layer.We show that the longitudinal librations should have an amplitude of about 30arcsec, independent of the composition of the core. We also estimate the tidal instability of the core, and show that should be slowly...
Saturn’s main rings exhibit variations in both their opacity and their spectral properties on a broad range of spatial scales, and the correlations between these parameters can provide insights into the processes that shape the composition and dynamics of the rings. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini Spacecraft has obtained spectra of the rings between...
Saturn is orbited by a half dozen ice rich middle-sized moons (MSMs) of diverse geology and composition. These comprise ∼4.4% of Saturn’s satellite mass; the rest is Titan, more massive per planet than Jupiter’s satellites combined. Jupiter has no MSMs. Disk-based models to explain these differences exist, but have various challenges and assumptions. We introduce the hypothesis that Saturn originally...
The Encke Gap is a 320-km-wide opening in Saturn’s outer A ring that contains the orbit of the small moon Pan and an array of dusty features composed of particles less than 100μm across. In particular, there are three narrow ringlets in this region that are not longitudinally homogeneous, but instead contain series of bright clumps. Using images obtained by the Cassini spacecraft, we track the motions...
The line intensities of the fundamental rotational transitions of H 13 CN and HC 15 N were observed towards two prestellar cores, L183 and L1544, and lead to molecular isotopic ratios 140⩽ 14 N/ 15 N⩽250 and 140⩽ 14 N/ 15 N⩽360, respectively. The range of values reflect genuine spatial variations within the cores. A comprehensive analysis of the available...
Using stereo generated topography of Dione, a moon of Saturn, we infer flexure across a prominent ridge on the leading hemisphere to estimate local elastic thickness and place constraints on Dione’s thermal evolution. Assuming topography is related to the flexing of a broken elastic plate, we estimate an effective elastic thickness of 3.5±1km. This local estimate is in good agreement with global values...
Extensive modeling of Mars in conjunction with in situ observations suggests that the annual average global mean surface temperature is Ts¯∼202K. Yet its effective temperature, i.e., the temperature at which a blackbody radiates away the energy it absorbs, is T e ∼208K. How can a planet with a CO 2 atmosphere have a mean annual surface temperature that is actually less than its effective...
Is Mars actively releasing organic and other minor gases into the atmosphere? We present a comprehensive search for trace species on Mars, targeting multiple volatile organic species (CH 4 , CH 3 OH, H 2 CO, C 2 H 6 , C 2 H 2 , C 2 H 4 ), hydroperoxyl (HO 2 ), several nitrogen compounds (N 2 O, NH 3 , HCN),...
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