The School of Earth and Atmospheric Sciences Presents Dr. Joseph O'Rourke, Arizona State University

Vigorous fluid motions drive dynamos today in Earth and all major planets except Mars and Venus. Here, I will show how magnetic histories of rock/metal planets directly depend on conditions during their accretion and differentiation. 

In particular, giant impacts and planetary size and water content are always critical to dynamo energetics. Precipitation of magnesium oxide boosts the likelihood of dynamo activity in Earth and Venus, but hydrogenation of the core of Mars destroyed its dynamo. 

My future plans center on comparative planetology to understand fundamental interior processes that affect planetary atmospheres and surfaces. In parallel with computational geodynamics, I aim to develop spacecraft missions that provide ground truth for my models. To illustrate, I will present my proposed SmallSat mission to (2) Pallas—the largest unexplored protoplanet in the main asteroid belt and parent of many near-Earth asteroids.