Colloquium: Clive Neal

Abstract: The Moon represents an end-member planetary body in terms of planetary differentiation. Its small size relative ton the other terrestrial planets means that planetary differentiation ceased early on in the process as the heat engine died down. This os reflected in the old age of the samples returned during the US "Apollo" and Soviet Union "Luna" programs, as well as from lunar meteorites. Therefore, understanding the structure, heat flow, and magnetic history of the Moon will allow us to understand the processes that affected other terrestrial planets early in their evolutionary history. The old lunar surface also preserves the early impact history of the inner solar system, which has implications for the origin of life on Earth and also on solar system evolution. This seminar will briefly review what we know about the Moon from previous missions and will outline the two lunar mission concepts that are named as New Frontiers class missions in the latest Planetary Sciences Division Decadal Survey. One will explore the internal structure and magnetic/thermal evolution of the Moon and one that will return samples from largest impact structure in the solar system, the South Pole-Aitken (SPA) Basin. The seminar will conclude by describing a petrographic method that can distinguish impact melts from pristine basalts, which is critical if SPA sample return is to be a success.

Clive Neal, Professor
Dept. Civil Engineering & Geological Sciences, University of Notre Dame