Search Publications
Nitrogen isotope fractionation and its consequence for Titan's atmospheric evolution
Lammer, H.; Owen, T.; Molina-Cuberos, G. J. +2 more
The first determination of the 15N/ 14N ratio in Titan's atmosphere comes from Earth-based millimetric wavelength spectroscopic observations of HC 15N/HC 14N. These measurements indicate that the bulk nitrogen is enriched in the heavy isotope 15N by about 4.5 times relative to the Earth value.…
Laboratory investigation on the formation of unsaturated nitriles in Titan's atmosphere
Kaiser, R. I.; Balucani, N.; Asvany, O. +3 more
Crossed molecular beam experiments of ground state cyano radicals, CN(X 2Σ +), with hydrocarbons acetylene (C 2H 2), ethylene (C 2H 4), methylacetylene (CH 3CCH), allene (H 2CCCH 2), dimethylacetylene (CH 3CCCH 3), and benzene (…
New photochemical model of Saturn's atmosphere
Ollivier, J. L.; Dobrijévic, M.; Parisot, J. P.
A new photochemical model of Saturn's atmosphere, which includes hydrocarbon (up to C 4 compounds) and oxygen compounds, is presented. This model derives from Neptune's model established by Dobrijévic et al. (2000. Planet. Space Sci., submitted). In this one-dimensional model, we consider vertical transport driven by molecular and eddy …
The 90-day oscillations of Jupiter's Great Red Spot revisited
Sánchez-Lavega, A.; Colas, F.; Lecacheux, J. +3 more
We have analyzed a large set of ground-based CCD images covering the period from 1993 to early 1999, to address the current status and behavior of the 90-day longitudinal oscillations of the Jovian Great Red Spot (GRS). The good temporal sampling of these data have been complemented with a small set of high resolution Hubble Space Telescope images…
An analytical model to predict the particle flux on spacecraft in the solar system
Jehn, R.
In this paper an analytical meteoroid flux model is presented which extends from 1 to 10 AU and covers a mass range from 10 -18 to 1 g. The basic flux curve of the model by Grün et al. (1985, Icarus 62, 244-272.) is modified by an analytical multiplication factor in order to approximate the meteoroid flux as predicted by the five-popula…
Wave signatures in the Jovian magnetosphere
Dougherty, Michele; Petkaki, Panagiota
Magnetometer data from the Ulysses Jupiter flyby are examined, in particular middle magnetosphere observations in the vicinity of the magnetodisk. Ion cyclotron waves are searched for in the heavy ion gyrofrequency regime (SO +2, SO +, K +, S +, Na +, O + and S ++
The atmospheric composition and structure of Jupiter and Saturn from ISO observations: a preliminary review
Lellouch, E.; Feuchtgruber, H.; Atreya, S. K. +4 more
Infrared spectra of Jupiter and Saturn have been recorded with the two spectrometers of the Infrared Space Observatory (ISO) in 1995-1998, in the 2.3-180 µm range. Both the grating modes ( R=150-2000) and the Fabry-Pérot modes ( R=8000-30,000) of the two instruments were used. The main results of these observations are (1) the detection of w…
Silicates in Hale-Bopp: hints from laboratory studies
Brucato, J. R.; Mennella, V.; Colangeli, L. +2 more
The recent passage of the Hale-Bopp (C/1995 O1) comet has provided the first opportunity to analyse the infrared spectral properties of a bright comet both from the ground and by the ISO space observatory. Previous works have already been dedicated to study the potential candidates to reproduce the cometary feature at 10 µm observed for diff…
Lyman-alpha observations of comet 46 P/Wirtanen with swan on SOHO: H2O production rate near 1997 perihelion
Schmidt, W.; Bertaux, J. L.; Lallement, R. +4 more
The SWAN instrument on board SOHO is a Lyman-α photometer able to map the sky intensity with a resolution of 1°, primarily devoted to the study of the large scale distribution of solar wind from its imprints on the interplanetary sky background. In addition SWAN was extensively used to map the Lyman α emission of several comets since launch in Dec…
Three years of Ulysses dust data: 1993-1995
Krüger, H.; Srama, R.; Hamilton, D. P. +18 more
The Ulysses spacecraft is orbiting the Sun on a highly inclined ellipse (i = 79°). After its Jupiter flyby in 1992 at a heliocentric distance of 5.4 AU, the spacecraftreapproached the inner solar system, flew over the Suns south polar region in September 1994,crossed the ecliptic plane at a distance of 1.3 AU in March 1995, and flew over the Suns …