title: Gravity field and internal structure of Mercury from MESSENGER.
abstract: Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/MR(2) = 0.353 ± 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(m)/C = 0.452 ± 0.035. A model for Mercury's radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.
authors.affiliation: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Smith
authors.forename: Maria T
authors.initials: MT
authors.lastname: Zuber
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Phillips
authors.forename: Sean C
authors.initials: SC
authors.lastname: Solomon
authors.forename: Steven A
authors.initials: SA
authors.lastname: Hauck
authors.forename: Frank G
authors.initials: FG
authors.lastname: Lemoine
authors.forename: Erwan
authors.initials: E
authors.lastname: Mazarico
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Neumann
authors.forename: Stanton J
authors.initials: SJ
authors.lastname: Peale
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Margot
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Johnson
authors.forename: Mark H
authors.initials: MH
authors.lastname: Torrence
authors.forename: Mark E
authors.initials: ME
authors.lastname: Perry
authors.forename: David D
authors.initials: DD
authors.lastname: Rowlands
authors.forename: Sander
authors.initials: S
authors.lastname: Goossens
authors.forename: James W
authors.initials: JW
authors.lastname: Head
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Taylor