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The Cassini flyby of Jupiter in 2000 provided spatially resolved spectra of Jupiters atmosphere using the Visual and Infrared Mapping Spectrometer (VIMS). These spectra contain a strong absorption at wavelengths from about 2.9 $mu$m to 3.1 $mu$m, previously noticed in a 3-$mu$m spectrum obtained by the Infrared Space Observatory (ISO) in 1996. While Brooke et al. (1998, Icarus 136, 1-13) were able to fit the ISO spectrum very well using ammonia ice as the sole source of particulate absorption, Sromovsky and Fry (2010, Icarus 210, 211-229), using significantly revised NH$_3$ gas absorption models, showed that ammonium hydrosulfide (NH$_4$SH) provided a better fit to the ISO spectrum than NH$_3$ , but that the best fit was obtained when both NH$_3$ and NH$_4$SH were present. Although the large FOV of the ISO instrument precluded identification of the spatial distribution of these two components, the VIMS spectra at low and intermediate phase angles show that 3-$mu$m absorption is present in zones and belts, in every region investigated, and both low- and high-opacity samples are best fit with a combination of NH$_4$SH and NH$_3$ particles at all locations. The best fits are obtained with a layer of small ammonia-coated particles ($rsim0.3$ $mu$m) overlying but often close to an optically thicker but still modest layer of much larger NH$_4$SH particles ($rsim 10$ $mu$m), with a deeper optically thicker layer, which might also be composed of NH$_4$SH. Although these fits put NH$_3$ ice at pressures less than 500 mb, this is not inconsistent with the lack of prominent NH$_3$ features in Jupiters longwave spectrum because the reflectivity of the core particles strongly suppresses the NH$_3$ absorption features, at both near-IR and thermal wavelengths.
We present Cassini VIMS observations of sun glitter -- wave-induced reflections from a liquid surface offset from a specular point -- on Kraken Mare. Sun glitter reveals rough sea surfaces around Kraken Mare, namely the coasts and narrow straits. The
Titan is one of the primary scientific objectives of the NASA ESA ASI Cassini Huygens mission. Scattering by haze particles in Titans atmosphere and numerous methane absorptions dramatically veil Titans surface in the visible range, though it can be
We present observations of 8 Galactic Bulge microlensing events taken with the 1.0m JKT on La Palma during 2000 June and July. The JKT observing schedule was optimized using a prioritizing algorithm to automatically update the target list. For most o
The flybys of Jupiter by the Voyager spacecraft in 1979, and over two decades later by Cassini in 2000, have provided us with unique datasets from two different epochs, allowing the investigation of seasonal change in the atmosphere. In this paper we
We characterise the origin and evolution of a mesoscale wave pattern in Jupiters North Equatorial Belt (NEB), detected for the first time at 5 $mu$m using a 2016-17 campaign of `lucky imaging from the VISIR instrument on the Very Large Telescope and