Search Publications
Condensation in Titan's atmosphere at the Huygens landing site
Yelle, R. V.; Lavvas, P.; Griffith, C. A.
We present a self-consistent description of Titan's aerosols-clouds-gases system and compare our results with the optical properties retrieved from measurements made by the Descent Imager/Spectral Radiometer (DISR) experiment on the Huygens probe (Tomasko, M.G. et al. [2008]. Planet. Space Sci. 56, 669-707). Our calculations include the condensati…
A high-amplitude thermal inertia anomaly of probable magnetospheric origin on Saturn's moon Mimas
Johnson, R. E.; Paranicas, C.; Spencer, J. R. +5 more
Spectral maps of Mimas' daytime thermal emission show a previously unobserved thermal anomaly on Mimas' surface. A sharp V-shaped boundary, centered at 0°N and 180°W, separates relatively warm daytime temperatures from a cooler anomalous region occupying low- to mid-latitudes on the leading hemisphere. Subsequent observations show the anomalous re…
Regional geomorphology and history of Titan's Xanadu province
Lorenz, R. D.; West, R. D.; Stiles, B. +19 more
Titan's enigmatic Xanadu province has been seen in some detail with instruments from the Cassini spacecraft. The region contains some of the most rugged, mountainous terrain on Titan, with relief over 2000 m. Xanadu contains evolved and integrated river channels, impact craters, and dry basins filled with smooth, radar-dark material, perhaps sedim…
Shoreline retreat at Titan's Ontario Lacus and Arrakis Planitia from Cassini Imaging Science Subsystem observations
Hayes, A. G.; McEwen, A. S.; Turtle, E. P. +1 more
Recent observations by Cassini's Imaging Science Subsystem reveal that part of the shoreline of Titan's Ontario Lacus has retreated by several kilometers and may indicate that the dark area that appeared at Arrakis Planitia (80°S, 120°W) in late 2004 has subsequently faded. These changes provide constraints on aspects of Titan's methane cycle, as …
Sorted clastic stripes, lobes and associated gullies in high-latitude craters on Mars: Landforms indicative of very recent, polycyclic ground-ice thaw and liquid flows
Balme, M. R.; Conway, S. J.; Grindrod, P. M. +1 more
Self-organised patterns of stone stripes, polygons, circles and clastic solifluction lobes form by the sorting of clasts from fine-grained sediments in freeze-thaw cycles. We present new High Resolution Imaging Science Experiment (HiRISE) images of Mars which demonstrate that the slopes of high-latitude craters, including Heimdal crater - just 25 …
A layer of ozone detected in the nightside upper atmosphere of Venus
Vandaele, A. C.; Montmessin, F.; Fedorova, A. +7 more
To date, ozone has only been identified in the atmospheres of Earth and Mars. This study reports the first detection of ozone in the atmosphere of Venus by the SPICAV ultraviolet instrument onboard the Venus Express spacecraft. Venusian ozone is characterized by a vertically confined and horizontally variable layer residing in the thermosphere at …
Stardust-NExT, Deep Impact, and the accelerating spin of 9P/Tempel 1
Licandro, Javier; Vincent, J. -B.; Bhatt, B. C. +68 more
The evolution of the spin rate of Comet 9P/Tempel 1 through two perihelion passages (in 2000 and 2005) is determined from 1922 Earth-based observations taken over a period of 13 year as part of a World-Wide observing campaign and from 2888 observations taken over a period of 50 days from the Deep Impact spacecraft. We determine the following sider…
Mid-IR, Far-IR, Raman micro-spectroscopy, and FESEM-EDX study of IDP L2021C5: Clues to its origin
Rotundi, A.; Dartois, E.; Brunetto, R. +8 more
Interplanetary Dust Particles (IDPs) are potentially of cometary origin. They may therefore provide important clues to a better understanding of the early Solar System physical and chemical conditions. A chondritic porous aggregate IDP (named L2021C5) was analyzed using mid to far FTIR (2-60 µm) micro-spectroscopy, Raman micro-spectroscopy, …
Sulfates and iron oxides in Ophir Chasma, Mars, based on OMEGA and CRISM observations
Neukum, Gerhard; Combe, Jean-Philippe; Gross, Christoph +5 more
We investigate the sulfate and iron oxide deposits in Ophir Chasma, Mars, based on short-wave infrared data from the Compact Reconnaissance Imaging Spectrometer for Mars - CRISM and from the Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité - OMEGA. Sulfates are detected mainly in two locations. In the valley between Ophir Mensa an…
Rotational dynamics and internal structure of Titan
Nimmo, Francis; Bills, Bruce G.
Estimates of the moments of inertia of Titan, as separately deduced from its gravitational field and spin pole orientation, are quite different. This discrepancy can be resolved if Titan is either not precessing as a rigid body (e.g. if the shell is decoupled from the interior by an ocean), or if the spin pole is not fully damped (e.g. due to atmo…