title: Exposed water ice deposits on the surface of comet 9P/Tempel 1.
abstract: We report the direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission. Three anomalously colored areas are shown to include water ice on the basis of their near-infrared spectra, which include diagnostic water ice absorptions at wavelengths of 1.5 and 2.0 micrometers. These absorptions are well modeled as a mixture of nearby non-ice regions and 3 to 6% water ice particles 10 to 50 micrometers in diameter. These particle sizes are larger than those ejected during the impact experiment, which suggests that the surface deposits are loose aggregates. The total area of exposed water ice is substantially less than that required to support the observed ambient outgassing from the comet, which likely has additional source regions below the surface.
authors.affiliation: Science Applications International Corporation (SAIC), Chantilly, VA 20151, USA. sunshinej@saic.com
authors.forename: J M
authors.initials: JM
authors.lastname: Sunshine
authors.forename: M F
authors.initials: MF
authors.lastname: A'Hearn
authors.forename: O
authors.initials: O
authors.lastname: Groussin
authors.forename: J-Y
authors.initials: JY
authors.lastname: Li
authors.forename: M J S
authors.initials: MJ
authors.lastname: Belton
authors.forename: W A
authors.initials: WA
authors.lastname: Delamere
authors.forename: J
authors.initials: J
authors.lastname: Kissel
authors.forename: K P
authors.initials: KP
authors.lastname: Klaasen
authors.forename: L A
authors.initials: LA
authors.lastname: McFadden
authors.forename: K J
authors.initials: KJ
authors.lastname: Meech
authors.forename: H J
authors.initials: HJ
authors.lastname: Melosh
authors.forename: P H
authors.initials: PH
authors.lastname: Schultz
authors.forename: P C
authors.initials: PC
authors.lastname: Thomas
authors.forename: J
authors.initials: J
authors.lastname: Veverka
authors.forename: D K
authors.initials: DK
authors.lastname: Yeomans
authors.forename: I C
authors.initials: IC
authors.lastname: Busko
authors.forename: M
authors.initials: M
authors.lastname: Desnoyer
authors.forename: T L
authors.initials: TL
authors.lastname: Farnham
authors.forename: L M
authors.initials: LM
authors.lastname: Feaga
authors.forename: D L
authors.initials: DL
authors.lastname: Hampton
authors.forename: D J
authors.initials: DJ
authors.lastname: Lindler
authors.forename: C M
authors.initials: CM
authors.lastname: Lisse
authors.forename: D D
authors.initials: DD
authors.lastname: Wellnitz
mesh_terms: D007053:Ice / Q000032:analysis*; D019110:Meteoroids; D013055:Spectrophotometry, Infrared
chemical_list: D007053:Ice