title: The Opportunity Rover's Athena science investigation at Meridiani Planum, Mars.
abstract: The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation. Hematite-rich spherules are embedded in the rock and eroding from them. We interpret these spherules to be concretions formed by postdepositional diagenesis, again involving liquid water.
authors.affiliation: Department of Astronomy, Space Sciences Building, Cornell University, Ithaca, NY 14853, USA. squyres@astro.cornell.edu
authors.forename: S W
authors.initials: SW
authors.lastname: Squyres
authors.forename: R E
authors.initials: RE
authors.lastname: Arvidson
authors.forename: J F
authors.initials: JF
authors.lastname: Bell
authors.forename: J
authors.initials: J
authors.lastname: Brückner
authors.forename: N A
authors.initials: NA
authors.lastname: Cabrol
authors.forename: W
authors.initials: W
authors.lastname: Calvin
authors.forename: M H
authors.initials: MH
authors.lastname: Carr
authors.forename: P R
authors.initials: PR
authors.lastname: Christensen
authors.forename: B C
authors.initials: BC
authors.lastname: Clark
authors.forename: L
authors.initials: L
authors.lastname: Crumpler
authors.forename: D J Des
authors.initials: DJ
authors.lastname: Marais
authors.forename: C
authors.initials: C
authors.lastname: d'Uston
authors.forename: T
authors.initials: T
authors.lastname: Economou
authors.forename: J
authors.initials: J
authors.lastname: Farmer
authors.forename: W
authors.initials: W
authors.lastname: Farrand
authors.forename: W
authors.initials: W
authors.lastname: Folkner
authors.forename: M
authors.initials: M
authors.lastname: Golombek
authors.forename: S
authors.initials: S
authors.lastname: Gorevan
authors.forename: J A
authors.initials: JA
authors.lastname: Grant
authors.forename: R
authors.initials: R
authors.lastname: Greeley
authors.forename: J
authors.initials: J
authors.lastname: Grotzinger
authors.forename: L
authors.initials: L
authors.lastname: Haskin
authors.forename: K E
authors.initials: KE
authors.lastname: Herkenhoff
authors.forename: S
authors.initials: S
authors.lastname: Hviid
authors.forename: J
authors.initials: J
authors.lastname: Johnson
authors.forename: G
authors.initials: G
authors.lastname: Klingelhöfer
authors.forename: A H
authors.initials: AH
authors.lastname: Knoll
authors.forename: G
authors.initials: G
authors.lastname: Landis
authors.forename: M
authors.initials: M
authors.lastname: Lemmon
authors.forename: R
authors.initials: R
authors.lastname: Li
authors.forename: M B
authors.initials: MB
authors.lastname: Madsen
authors.forename: M C
authors.initials: MC
authors.lastname: Malin
authors.forename: S M
authors.initials: SM
authors.lastname: McLennan
authors.forename: H Y
authors.initials: HY
authors.lastname: McSween
authors.forename: D W
authors.initials: DW
authors.lastname: Ming
authors.forename: J
authors.initials: J
authors.lastname: Moersch
authors.forename: R V
authors.initials: RV
authors.lastname: Morris
authors.forename: T
authors.initials: T
authors.lastname: Parker
authors.forename: J W
authors.initials: JW
authors.lastname: Rice
authors.forename: L
authors.initials: L
authors.lastname: Richter
authors.forename: R
authors.initials: R
authors.lastname: Rieder
authors.forename: M
authors.initials: M
authors.lastname: Sims
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: P
authors.initials: P
authors.lastname: Smith
authors.forename: L A
authors.initials: LA
authors.lastname: Soderblom
authors.forename: R
authors.initials: R
authors.lastname: Sullivan
authors.forename: H
authors.initials: H
authors.lastname: Wänke
authors.forename: T
authors.initials: T
authors.lastname: Wdowiak
authors.forename: M
authors.initials: M
authors.lastname: Wolff
authors.forename: A
authors.initials: A
authors.lastname: Yen
mesh_terms: D001272:Atmosphere; D019419:Evolution, Planetary; D005118:Extraterrestrial Environment; D005290:Ferric Compounds; D019015:Geologic Sediments; D018535:Mars; D008903:Minerals; D017640:Silicates; D018531:Spacecraft; D014867:Water; D014919:Wind
chemical_list: D005290:Ferric Compounds; D008903:Minerals; D017640:Silicates; C060346:basalt; D014867:Water; C000499:ferric oxide