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On the colors of Jupiter's satellite Io - Irradiation of solid sulfur at 77 KThe colors of seven sulfur allotropes at 77 K have been investigated both before and after irradiation by a high-pressure mercury lamp. S8 is white at 77 K but turns intense yellow within a few minutes on irradiation through quartz or DURAN. On warming, the yellow species (presumably chain-like sulfur diradicals characterized by an absorption at 430 nm) decomposes near 260 K and polymeric sulfur (S-infinity) is formed; the sample color changes gradually to the very similar color of an S8-S-infinity mixture, resulting in no visually detectable color change with temperatures from 77 K to 260 K. This is consistent with the lack of posteclipse brightening on Io. Other sulfur forms also turn intense yellow (S7, S10), grayish yellow (S12, S20, S-infinity), or brownish yellow (S6) on irradiation at 77 K, and these colors also change to the normal colors of the starting materials on warming to 298 K. It is suggested that the yellowish features on Io are caused by the effect of solar radiation on elemental sulfur. The yellow color thus produced may subsequently be modified by deposits of SO2 frosts and volcanic ash.
Document ID
19860051359
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Steudel, R.
(Technische Univ. Berlin, Germany)
Holdt, G.
(Berlin, Technische Universitaet Germany)
Young, A. T.
(San Diego State University CA, United States)
Date Acquired
August 12, 2013
Publication Date
April 10, 1986
Publication Information
Publication: Journal of Geophysical Research
Volume: 91
ISSN: 0148-0227
Subject Category
Lunar And Planetary Exploration
Accession Number
86A36097
Funding Number(s)
CONTRACT_GRANT: NAGW-250
Distribution Limits
Public
Copyright
Other

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