Planetary Lunch Series (PLS) – Jim Head (Brown University)

Title: Lunar Nearside-Farside Mare Basalt Asymmetry: The Combined Role of Global Crustal Thickness and South Pole-Aitken Basin-Induced Lithospheric Thickening

Abstract: The first acquisition of lunar farside images by Luna 3 in 1958 revealed a substantial NS/FS asymmetry in mare basalt (MB) deposits,. In the following decades, many additional NS/FS asymmetries have been documented (e.g., albedo, topography, crustal thickness, composition (heat producing element (HPE), iron, titanium), terrane types, etc.). Among the explanations for the MB asymmetry are: asymmetric accretion; asymmetric degree 1 convection thickens crust; SPA basin impact or other factors bringing HPE to NS PKT terrain; asymmetric LMO convection; incomplete post-LMO residual layer foundering; late-stage LMO impact events, etc., all potentially causing, or contributing to, the NS/FS mare basalt asymmetry observed . We investigate the key causative factors in the observed NS/FS mare basalt asymmetry and propose that it is due to two combined factors: NS/FS crustal thickness, and SPA basin event-accelerated lithospheric thickening.

About this Series: The MIT Planetary Lunch Seminar [PLS] is a weekly seminar series organized within the EAPS department. Colloquia topics span the range of research interests of the department’s planetary sciences research program. The seminars take place on Tuesdays from 12:15–1:30 pm, unless otherwise noted (term-time only). Speakers include members of the MIT community and visitors. Talks are intended to appeal to graduate students, postdocs, research scientists, and faculty with a background in planetary science. For more information and Zoom password contact: planetary-org@mit.edu