Search Publications
Thermal observations of Saturn's main rings by Cassini CIRS: Phase, emission and solar elevation dependence
Altobelli, Nicolas; Spilker, Linda J.; Leyrat, Cedric +1 more
Two and a half years after Saturn orbit insertion (SOI) the Cassini composite infrared spectrometer (CIRS) has acquired an extensive set of thermal measurements (including physical temperature and filling factor) of Saturn's main rings for a number of different viewing geometries, most of which are not available from Earth. Thermal mapping of both…
Venus Doppler winds at cloud tops observed with ESPaDOnS at CFHT
Lellouch, Emmanuel; Widemann, Thomas; Donati, Jean-François
We present new wind measurements in Venus' lower mesosphere from visible spectroscopy during the 2007 worldwide coordinated ground campaign in support of ESA's Venus Express mission. These observations consisted of high-resolution spectra of Fraunhofer lines in the entire visible range (0.37-1.05 µm) to measure the winds near 68 km using the…
Suprathermal electron fluxes on the nightside of Mars: ASPERA-3 observations
Barabash, S.; Lundin, R.; Woch, J. +4 more
Recently aurora-type UV emissions were discovered on the nightside of Mars [Bertaux, J.-L., Leblanc, F., Witasse, O., et al., 2005. Discovery of an aurora on Mars. Nature 439, doi:10.1038/nature03603]. It was suggested that these emissions are produced by suprathermal electrons with energies of tens of eV, rather than by the electrons with spectra…
Hemispheric distributions of HCl above and below the Venus’ clouds by ground-based 1.7 µm spectroscopy
Imamura, T.; Kasaba, Y.; Sagawa, H. +8 more
The abundance of hydrogen chloride (HCl) in the Venus atmosphere was measured by ground-based IR spectroscopy. The dayside measurements were performed in May 2007 with a resolution of 40,000, and the nightside measurements in October 1999 with a resolution of 1000. The hemispheric distributions of the HCl mixing ratio measured above the Venus' clo…
The Venusian induced magnetosphere: A case study of plasma and magnetic field measurements on the Venus Express mission
Coates, A. J.; Kallio, E.; Fedorov, A. +49 more
Plasma and magnetic field measurements made onboard the Venus Express on June 1, 2006, are analyzed and compared with predictions of a global model. It is shown that in the orbit studied, the plasma and magnetic field observations obtained near the North Pole under solar minimum conditions were qualitatively and, in many cases also, quantitatively…
New laboratory measurements of CH 4 in Titan's conditions and a reanalysis of the DISR near-surface spectra at the Huygens landing site
Lellouch, E.; Bézard, B.; Coustenis, A. +5 more
Laboratory spectra of methane-nitrogen mixtures have been recorded in the near-infrared range (1.0-1.65 µm) in conditions similar to Titan's near surface, to facilitate the interpretation of the DISR/DLIS (DISR - Descent Imager/Spectral Radiometer) spectra taken during the last phase of the descent of the Huygens Probe, when the surface was …
Observable effects of convection and gravity waves on the Venus condensational cloud
Toon, Owen B.; McGouldrick, Kevin
We present results of a simple two-dimensional model investigating the observable effects that convective motions and gravity waves can have on the condensational Venus cloud. Gravity waves have been observed in the Venus atmosphere in the form of temperature scintillations in the Magellan and Pioneer Venus occultation data. Multiple in situ probe…
Asymmetry of plasma fluxes at Mars. ASPERA-3 observations and hybrid simulations
Barabash, S.; Lundin, R.; Winningham, J. D. +6 more
The asymmetry of fluxes of solar wind and planetary ions is studied by using the ASPERA-3 observations onboard the Mars Express spacecraft in February 2004 to March 2006. Due to the small scale of the Martian magnetosphere and its induced origin, the flow pattern near Mars is sensitive to the directions of the interplanetary magnetic and electric …
Infrared observations of Saturn's rings by Cassini CIRS : Phase angle and local time dependence
Altobelli, Nicolas; Spilker, Linda J.; Ferrari, Cecile +2 more
Since the Saturn orbit insertion (SOI) of the Cassini spacecraft, in July 2004, the Cassini Composite Infrared Spectrometer (CIRS) has obtained a large number of thermal infrared spectra of Saturn's rings. Over the two and a half years of observations to date, ring temperatures were retrieved for a large range of unique geometries, inaccessible fr…
Titan's aerosols: Comparison between our model and DISR findings
Bar-Nun, A.; Dimitrov, V.; Tomasko, M.
Our model [Dimitrov, V., Bar-Nun, A., 1999. A model of energy dependent agglomeration of hydrocarbon aerosol particles and implication to Titan's aerosol. J. Aerosol. Sci. 30(1), 35-49] describes the experimentally found polymerization of C 2H 2 and HCN to form aerosol embryos, their growth and adherence to form various aeros…