Near infrared reflection spectra of ammonia frost: Interpretation of the upper clouds of Saturn

Slobodkin, L. S.; Buyakov, I. F.; Cess, R. D.; Caldwell, John

doi:10.1016/0022-4073(78)90052-3

Cited by 29 publications

(12 citation statements)

References 17 publications

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“…Bands at the same wavelengths were also seen in an ammonia hydrate examined by Schmitt et al (1998); they are clearly different in wavelength from pure NH 3 bands (e.g., Slobodkin et al, 1978;Sill et al, 1980Sill et al, , 1981Schmitt et al, 1998). In reflectance spectra of granulated, frozen NH 4 OH, Brown et al (1988) found several absorption bands, including those at 1.99 and 2.21 µm (the spectra were relatively low resolution, and the wavelengths could not be determined with any greater precision than three significant figures).…”

Section: Nh 3 and Ammonium Compoundsmentioning

confidence: 84%

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

Cruikshank¹,

Owen²,

Ore³

et al. 2005

Icarus

101

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We present spectra of Saturn's icy satellites Mimas, Enceladus, Tethys, Dione, Rhea, and Hyperion, 1.0-2.5 µm, with data extending to shorter (Mimas and Enceladus) and longer (Rhea and Dione) wavelengths for certain objects. The spectral resolution (R = λ/ λ) of the data shown here is in the range 800-1000, depending on the specific instrument and configuration used; this is higher than the resolution (R = 225 at 3 µm) afforded by the Visual-Infrared Mapping Spectrometer on the Cassini spacecraft. All of the spectra are dominated by water ice absorption bands and no other features are clearly identified. Spectra of all of these satellites show the characteristic signature of hexagonal H 2 O ice at 1.65 µm. We model the leading hemisphere of Rhea in the wavelength range 0.3-3.6 µm with the Hapke and the Shkuratov radiative transfer codes and discuss the relative merits of the two approaches to fitting the spectrum. In calculations with both codes, the only components used are H 2 O ice, which is the dominant constituent, and a small amount of tholin (Ice Tholin II). Tholin in small quantities (few percent, depending on the mixing mechanism) appears to be an essential component to give the basic red color of the satellite in the region 0.3-1.0 µm. The quantity and mode of mixing of tholin that can produce the intense coloration of Rhea and other icy satellites has bearing on its likely presence in many other icy bodies of the outer Solar System, both of high and low geometric albedos. Using the modeling codes, we also establish detection limits for the ices of CO 2 (a few weight percent, depending on particle size and mixing), CH 4 (same), and NH 4 OH (0.5 weight percent) in our globally averaged spectra of Rhea's leading hemisphere. New laboratory spectral data for NH 4 OH are presented for the purpose of detection on icy bodies. These limits for CO 2 , CH 4 , and NH 4 OH on Rhea are also applicable to the other icy satellites for which spectra are presented here. The reflectance spectrum of Hyperion shows evidence for a broad, unidentified absorption band centered at 1.75 µm.

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Section: Nh 3 and Ammonium Compoundsmentioning

confidence: 84%

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

Cruikshank¹,

Owen²,

Ore³

et al. 2005

Icarus

101

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“…CH4 and NH3 constitute the main components of the Jovian [16] and Saturnian [17] atmospheres. Recently their presence has also been reported for Uranus [18]and Neptune [19].…”

Section: Targetsmentioning

confidence: 99%

Total-cross-section measurements for electron scattering byNH3,SiH4
Zecca
¹
,
Karwasz
²
,
Brusa
³

1992
Phys. Rev. A
96
8
49
2
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Total cross sections for electron scattering have been measured in the 75 WOO-eV energy range for NH3, SiH4, and H2S. For these gases, as well as for CH4 and H20, cross sections have been fitted with a Born-like formula containing two parameters for each gas. The high-energy parameter of the fit to the cross sections has been related to the bond length of molecules. Partitioning of total cross sections into inelastic and elastic cross sections for these gases is discussed on the basis of available experimental data.PACS number(s): 34.80.Bm, 34.80.Gs

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“…16 -19 At intermediate temperatures, there have been a variety of contradictory spectra reported for the metastable phase in the literature. 15,16,[19][20][21][22] The contradiction in the literature has arisen from early results by Staats and Morgan 20 that labeled the metastable and crystalline phase spectra incorrectly, and later researchers continued to use their nomenclature for the misidentified spectra. To some degree this has been addressed in previous reports, but the true metastable phase of ammonia has not yet been accurately described.…”

Section: Introductionmentioning

confidence: 96%

Infrared spectroscopy of the solid phases of ammonia

Holt

Sadoskas

Pursell

2004

The Journal of Chemical Physics

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Thin films of solid ammonia (NH(3) and ND(3)) have been characterized using low temperature (25-110 K) Fourier-transform infrared (FTIR) spectroscopy, and the three solid phase (amorphous, metastable, and crystalline) spectra are reported. This work has been motivated by confusion in the literature about the metastable and crystalline phases as a result of an early erroneous report by Staats and Morgan [(J. Chem. Phys. 31, 553 (1959)]. Although the crystalline phase has subsequently been reported correctly, the metastable phase has not been described in the literature in detail. The unique characteristics of the metastable phase, reported here for the first time, include multiple peaks in the nu(2) and nu(3) regions and peak intensities that are dependent on the deposition temperature. This behavior may be the result of (a) preferential molecular orientations in the solid, or (b) exciton splitting due to different crystal shapes in the solid. The amorphous and metastable phases of deuterated ammonia are also reported for the first time.

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Near infrared reflection spectra of ammonia frost: Interpretation of the upper clouds of Saturn

Cited by 29 publications

References 17 publications

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

Total-cross-section measurements for electron scattering byNH3,SiH4
Zecca
¹
,
Karwasz
²
,
Brusa
³

1992
Phys. Rev. A
96
8
49
2
View full text Add to dashboard Cite

Infrared spectroscopy of the solid phases of ammonia

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Near infrared reflection spectra of ammonia frost: Interpretation of the upper clouds of Saturn

Cited by 29 publications

References 17 publications

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

A spectroscopic study of the surfaces of Saturn's large satellites: HO ice, tholins, and minor constituents

Total-cross-section measurements for electron scattering byNH3,SiH4Zecca1, Karwasz2, Brusa3 1992Phys. Rev. A968492View full textAdd to dashboardCite

Infrared spectroscopy of the solid phases of ammonia

Contact Info

Product

Resources

About

Total-cross-section measurements for electron scattering byNH3,SiH4
Zecca
¹
,
Karwasz
²
,
Brusa
³

1992
Phys. Rev. A
96
8
49
2
View full text Add to dashboard Cite