Collaborative Research: GLOW: Basal magma ocean dynamos of early Earth, Venus, and the Moon

University Of Texas At Austin, Austin TX

Investigators

Abstract

The origin of the ancient magnetic fields of Earth and its nearest neighbors, Venus and the Moon, is not well understood. The program will aim to understand if a dynamo generated by a magma ocean could have sustained Earth’s early magnetic field. The project will also determine for how long a dynamo may have existed on Venus and if such a dynamo was responsible for the high intensity magnetic field in the early history of the Moon. All modifications to the models will be open source for the science community. The work will be aired on the public service radio program EarthDate. Undergraduate students will join the team to run dynamo simulation numerical models, develop skills in data analytics and computational tools that will enhance professional development. The origin of ancient magnetic fields in terrestrial planets and moons prior to formation of the inner core is a long-standing question. Basal magma ocean dynamos have been hypothesized as mechanisms to explain how the Earth was able to maintain a magnetic field before the onset of inner core growth. This program will investigate the degree and mechanisms of dynamic and magnetic coupling between the lowermost liquid mantle and the iron-alloy core in the early Earth, the Moon and Venus. The project will determine how stable stratification in the basal magma ocean or core modulates magnetic field generation and attenuation, as well as mixing between these reservoirs. The team will simulate dynamos with different transport properties, such as electrical conductivity, thermal diffusivity, and kinematic viscosity, in the basal magma ocean and the core. These calculations will determine whether basal magma ocean dynamos can generate magnetic fields that are consistent with observational constraints. A better characterization of magnetic field generation in terrestrial planets and moons will advance the understanding of basal magma ocean dynamos in exoplanets. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.