Laboratory reflection spectra for the determination of chemical composition of icy bodies

Color and the Vertical Structure in Jupiter's Belts, Zones, and Weather Systems

“…These two holes are among the very few locations where a cloud this deep is found and may be consistent with sensing to the NH 4 SH cloud deck. The NH 4 SH cloud, if it exists, should condense at about 1.6 bars in Jupiter's atmosphere (Weidenschilling and Lewis 1973) and could be quite dark at 410 nm (Lebofsky and Fegley 1976). The cloud layer seen near 1.7 bars is consistent with IR observations of a cloud deck near this pressure level (Terrile and Westphal 1977, Roos-Serote et al 2000.…”

Coordinated 1996 HST and IRTF Imaging of Neptune and Triton II. Implications of Disk-Integrated Photometry

“…This is equivalent to a strong decrease in the single-scattering albedo of particulates in this layer, to ∼0.8 at 0.9 µm, in approximate agreement with Baines and Smith (1990) and Baines and Hammel (1994). This is not a physically appealing solution because the obvious candidate cloud materials (H 2 S or NH 3 ) do not have the proper red-absorbing characteristic, as evident from frost spectra of Lebofsky and Fegley (1976). Nevertheless, the model spectrum, shown as the heavy solid curve in Fig.…”

“…At 1 µm the difference between the two inferred single-scattering albedos is larger than the difference between various results in the CCD spectral range. Laboratory measurements by Lebofsky and Fegley (1976) and by Sill (1973) show that neither of the primary candidate cloud components (H 2 S or NH 3 ) has an absorption feature that can explain the 0.6-0.7 µm dip in the inferred single-scattering albedo. While the pure frosts are relatively flat across the 0.3-1.03 µm spectral range, irradiated frosts do have a reflectance dip near 0.6 µm.…”

Hydrate sulfuric acid after sulfur implantation in water ice

“…It is also interesting to note the absence of H 2 S in our experiments, and the fact that the polymer-like sulfur residues that are obtained after photolysis and radiolysis of sulfur bearing species (e.g. Lebofsky and Fegley 1976;Strazzulla et al 1993), well reproduce the Europa observed reflectance spectrum (Carlson et al 1999b Fig. 2).…”