title: Fluid core size of Mars from detection of the solar tide.
abstract: The solar tidal deformation of Mars, measured by its k2 potential Love number, has been obtained from an analysis of Mars Global Surveyor radio tracking. The observed k2 of 0.153 +/- 0.017 is large enough to rule out a solid iron core and so indicates that at least the outer part of the core is liquid. The inferred core radius is between 1520 and 1840 kilometers and is independent of many interior properties, although partial melt of the mantle is one factor that could reduce core size. Ice-cap mass changes can be deduced from the seasonal variations in air pressure and the odd gravity harmonic J3, given knowledge of cap mass distribution with latitude. The south cap seasonal mass change is about 30 to 40% larger than that of the north cap.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. Charles.F.Yoder@jpl.nasa.gov
authors.forename: C F
authors.initials: CF
authors.lastname: Yoder
authors.forename: A S
authors.initials: AS
authors.lastname: Konopliv
authors.forename: D N
authors.initials: DN
authors.lastname: Yuan
authors.forename: E M
authors.initials: EM
authors.lastname: Standish
authors.forename: W M
authors.initials: WM
authors.lastname: Folkner
mesh_terms: D001272:Atmosphere; D004367:Dry Ice; D006112:Gravitation; D018535:Mars; D008433:Mathematics; D011312:Pressure; D012399:Rotation; D013696:Temperature
chemical_list: D004367:Dry Ice