Premium
Detectability of Remanent Magnetism in the Crust of Venus
Author(s) -
O'Rourke J. G.,
Buz J.,
Fu R. R.,
Lillis R. J.
Publication year - 2019
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 - 10.1029/2019gl082725
Subject(s) - geology , dynamo , venus , geophysics , rock magnetism , magnetism , thermoremanent magnetization , remanence , crust , volcano , astrobiology , magnetization , paleontology , physics , magnetic field , quantum mechanics
Observations of planetary magnetic fields provide fundamental insights into the origin and evolution of terrestrial planets. However, whether Venus ever hosted a dynamo is unknown. Here we show that crustal remanent magnetism is a potentially observable consequence of an ancient Venusian dynamo, in contrast to previous studies that dismissed this possibility. Past spacecraft measurements only exclude crustal magnetization near the Venera 4 landing site and northward of 50° South latitude for >150‐km coherence scales and strong magnetization intensities. Magnetite grains with sizes commonly observed in volcanic rocks can retain thermoremanent magnetism at Venusian conditions for >1 billion years. Depths to the Curie temperature of magnetite are ~5–40 km and typically less than predicted crustal thicknesses at our analyzed localities. Aerial platforms could detect expected magnetizations at horizontal scales similar to the ~50‐km operating altitude. Any detection would validate models of planetary accretion, geologic processes, and climate history.