title: Europa's differentiated internal structure: inferences from four Galileo encounters.
abstract: Radio Doppler data from four encounters of the Galileo spacecraft with the jovian moon Europa have been used to refine models of Europa's interior. Europa is most likely differentiated into a metallic core surrounded by a rock mantle and a water ice-liquid outer shell, but the data cannot eliminate the possibility of a uniform mixture of dense silicate and metal beneath the water ice-liquid shell. The size of a metallic core is uncertain because of its unknown composition, but it could be as large as about 50 percent of Europa's radius. The thickness of Europa's outer shell of water ice-liquid must lie in the range of about 80 to 170 kilometers.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Anderson
authors.forename: G
authors.initials: G
authors.lastname: Schubert
authors.forename: R A
authors.initials: RA
authors.lastname: Jacobson
authors.forename: E L
authors.initials: EL
authors.lastname: Lau
authors.forename: W B
authors.initials: WB
authors.lastname: Moore
authors.forename: W L
authors.initials: WL
authors.lastname: Sjogren
mesh_terms: D005118:Extraterrestrial Environment; D005296:Ferrous Compounds; D007053:Ice; D007501:Iron; D018538:Jupiter; D017640:Silicates; D014867:Water
chemical_list: D005296:Ferrous Compounds; D007053:Ice; D017640:Silicates; D014867:Water; D007501:Iron; C022597:ferrous sulfide