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Evidence for a low bulk crustal density for Mars from gravity and topography
Author(s) -
Goossens Sander,
Sabaka Terence J.,
Genova Antonio,
Mazarico Erwan,
Nicholas Joseph B.,
Neumann Gregory A.
Publication year - 2017
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 - 10.1002/2017gl074172
Subject(s) - geology , mars exploration program , crust , planet , gravitational field , geophysics , density contrast , volcano , gravity anomaly , terrestrial planet , geodesy , impact crater , astrobiology , seismology , paleontology , physics , astronomy , astrophysics , oil field
Knowledge of the average density of the crust of a planet is important in determining its interior structure. The combination of high‐resolution gravity and topography data has yielded a low density for the Moon's crust, yet for other terrestrial planets the resolution of the gravity field models has hampered reasonable estimates. By using well‐chosen constraints derived from topography during gravity field model determination using satellite tracking data, we show that we can robustly and independently determine the average bulk crustal density directly from the tracking data, using the admittance between topography and imperfect gravity. We find a low average bulk crustal density for Mars, 2582 ± 209 kg m −3 . This bulk crustal density is lower than that assumed until now. Densities for volcanic complexes are higher, consistent with earlier estimates, implying large lateral variations in crustal density. In addition, we find indications that the crustal density increases with depth.