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Higher order statistics of planetary gravities and topographies
Author(s) -
Kaula William M.
Publication year - 1993
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl03086
Subject(s) - mars exploration program , martian , geology , venus , skewness , geophysics , equilateral triangle , planet , mantle (geology) , physics , geodesy , astrobiology , geometry , mathematics , astrophysics , statistics
The statistical properties of Earth, Venus, Mars, Moon, and a 3‐D mantle convection model are compared. The higher order properties are expressed by third and fourth moments: i.e., as mean products over equilateral triangles (defined as coskewance) and equilateral quadrangles (defined as coexance). For point values, all the fields of real planets have positive skewness, ranging from slightly above zero for Lunar gravity to 2.6σ³ for Martian gravity (σ is rms magnitude). Six of the eight excesses are greater than Gaussian (3σ 4 ), ranging from 2.0σ 4 for Earth topography to 18.6σ 4 , for Martian topography. The coskewances and coexances drop off to zero within 20° arc in most cases. The mantle convective model has zero skewness and excess slightly less than Gaussian, probably arising from viscosity variations being only radial.