Search Publications
Hydrogen density in the dayside venusian exosphere derived from Lyman-α observations by SPICAV on Venus Express
Bertaux, J. -L.; Chaufray, J. -Y.; Leblanc, F. +2 more
A series of observations of the venusian hydrogen corona made by SPICAV on Venus Express are analyzed to estimate the amount of hydrogen in the exosphere of Venus. These observations were made between November 2006 and July 2007 at altitudes from 1000 km to 8000 km on the dayside. The Lyman-α brightness profiles derived are reproduced by the sum o…
Sunlight refraction in the mesosphere of Venus during the transit on June 8th, 2004
Rondi, S.; Sütterlin, P.; Tanga, P. +6 more
Many observers in the past gave detailed descriptions of the telescopic aspect of Venus during its extremely rare transits across the Solar disk. In particular, at the ingress and egress, the portion of the planet’s disk outside the Solar photosphere has been repeatedly perceived as outlined by a thin, bright arc (“aureole”). Those historical visu…
The O2 nightglow in the martian atmosphere by SPICAM onboard of Mars-Express
Gondet, B.; Reberac, A.; Montmessin, F. +5 more
We present observations of the O2(a1Δg) nightglow at 1.27 µm on Mars using the SPICAM IR spectrometer onboard of the Mars Express orbiter. In contrast to the O2(a1Δg) dayglow that results from the ozone photodissociation, the O2(a1Δg) nightglow…
A predator-prey model for moon-triggered clumping in Saturn's rings
Colwell, Joshua E.; Esposito, Larry W.; Sremčević, Miodrag +4 more
UVIS occultation data show clumping in Saturn's F ring and at the B ring outer edge, indicating aggregation and disaggregation at these locations that are perturbed by Prometheus and by Mimas. The inferred timescales range from hours to months. Occultation profiles of the edge show wide variability, indicating perturbations by local mass aggregati…
Tidal control of jet eruptions on Enceladus as observed by Cassini ISS between 2005 and 2007
Spitale, J. N.; Helfenstein, P.; Hurford, T. A.
Observations of Enceladus have revealed active jets of material erupting from cracks on its south polar surface. It has previously been proposed that diurnal tidal stress, driven by Enceladus' orbital eccentricity, may actively produce surface movement along these cracks daily and thus may regulate when eruptions occur. Our analysis of the stress …
The growth of wind-waves in Titan's hydrocarbon seas
Lorenz, Ralph D.; Hayes, Alexander G.
Ocean wave growth on Titan is considered. The classic Sverdrup-Munk theory for terrestrial wave growth is applied to Titan, and is compared with a simple energy balance model that exposes the effect of Titan's environmental parameters (air density, gravity, and fluid density). These approaches are compared with the only previously-published (semi-…
Dust levitation as a major resurfacing process on the surface of a saturnian icy satellite, Atlas
Hirata, Naoyuki; Miyamoto, Hideaki
A small inner satellite of Saturn, Atlas, has an enigmatic saucer-like shape explained by an accumulation of particles from A-ring of Saturn. However, its unusual smooth surface remains unexplained. Gardening through continuous particle impact events cannot be a unique explanation for the smoothness, because Prometheus does not exhibit a similar s…
The distribution of carbon monoxide in the lower atmosphere of Venus
Bailey, Jeremy; Cotton, Daniel V.; Crisp, D. +1 more
We have obtained spatially resolved near-infrared spectroscopy of the Venus nightside on 15 nights over three observing seasons. We use the depth of the CO absorption band at 2.3 µm to map the two-dimensional distribution of CO across both hemispheres. Radiative transfer models are used to relate the measured CO band depth to the volume mixi…
Lunar iron abundance determination using the 2-µm absorption band parameters
Bhatt, Megha; Mall, Urs; Bugiolacchi, Roberto +4 more
In this work we report the first employment of the 2-µm absorption band parameters to estimate FeO weight percentage (wt.%) abundances from high-resolution Near-Infrared (NIR) lunar data, as measured by the SIR-2 instrument on board Chandrayaan-1. Our method is based on the algorithm originally developed by Le Mouélic et al. (Le Mouélic, S.,…
Identification and physical properties of craters on Asteroid (2867) Steins
Jorda, L.; Lamy, P.; Barbieri, C. +2 more
We report on the physical properties of the craters of Asteroid (2867) Steins based on an analysis of images obtained with the OSIRIS instrument during the Rosetta flyby that took place on 5 September 2008. To compensate for the limited spatial resolution of the images and unfavorable illumination conditions, we applied three different filtering t…