title: Near-infrared spectroscopy and spectral mapping of Jupiter and the Galilean satellites: results from Galileo's initial orbit.
abstract: The Near Infrared Mapping Spectrometer performed spectral studies of Jupiter and the Galilean satellites during the June 1996 perijove pass of the Galileo spacecraft. Spectra for a 5-micrometer hot spot on Jupiter are consistent with the absence of a significant water cloud above 8 bars and with a depletion of water compared to that predicted for solar composition, corroborating results from the Galileo probe. Great Red Spot (GRS) spectral images show that parts of this feature extend upward to 240 millibars, although considerable altitude-dependent structure is found within it. A ring of dense clouds surrounds the GRS and is lower than it by 3 to 7 kilometers. Spectra of Callisto and Ganymede reveal a feature at 4. 25 micrometers, attributed to the presence of hydrated minerals or possibly carbon dioxide on their surfaces. Spectra of Europa's high latitudes imply that fine-grained water frost overlies larger grains. Several active volcanic regions were found on Io, with temperatures of 420 to 620 kelvin and projected areas of 5 to 70 square kilometers.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109, USA.
authors.forename: R
authors.initials: R
authors.lastname: Carlson
authors.forename: W
authors.initials: W
authors.lastname: Smythe
authors.forename: K
authors.initials: K
authors.lastname: Baines
authors.forename: E
authors.initials: E
authors.lastname: Barbinis
authors.forename: K
authors.initials: K
authors.lastname: Becker
authors.forename: R
authors.initials: R
authors.lastname: Burns
authors.forename: S
authors.initials: S
authors.lastname: Calcutt
authors.forename: W
authors.initials: W
authors.lastname: Calvin
authors.forename: R
authors.initials: R
authors.lastname: Clark
authors.forename: G
authors.initials: G
authors.lastname: Danielson
authors.forename: A
authors.initials: A
authors.lastname: Davies
authors.forename: P
authors.initials: P
authors.lastname: Drossart
authors.forename: T
authors.initials: T
authors.lastname: Encrenaz
authors.forename: F
authors.initials: F
authors.lastname: Fanale
authors.forename: J
authors.initials: J
authors.lastname: Granahan
authors.forename: G
authors.initials: G
authors.lastname: Hansen
authors.forename: P
authors.initials: P
authors.lastname: Herrera
authors.forename: C
authors.initials: C
authors.lastname: Hibbitts
authors.forename: J
authors.initials: J
authors.lastname: Hui
authors.forename: P
authors.initials: P
authors.lastname: Irwin
authors.forename: T
authors.initials: T
authors.lastname: Johnson
authors.forename: L
authors.initials: L
authors.lastname: Kamp
authors.forename: H
authors.initials: H
authors.lastname: Kieffer
authors.forename: F
authors.initials: F
authors.lastname: Leader
authors.forename: P
authors.initials: P
authors.lastname: Weissman
mesh_terms: D000641:Ammonia / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D005118:Extraterrestrial Environment; D006878:Hydroxides / Q000032:analysis; D018538:Jupiter; D008697:Methane / Q000032:analysis; D010720:Phosphines / Q000032:analysis; D019265:Spectroscopy, Near-Infrared; D014867:Water / Q000032:analysis
chemical_list: D006878:Hydroxides; D010720:Phosphines; D014867:Water; D002245:Carbon Dioxide; D000641:Ammonia; C044646:phosphine; D008697:Methane