Events Calendar

Douglas Hemingway (DTM Washington DC) : «Magnetic anomalies and the color of the Moon—insights from lunar swirls»

Friday 24 May 2019, 13:00 - 14:00
by Mickaël BONNIN

An enduring mystery since Apollo is that, in spite of the Moon's lack of a global magnetic field, the surface is nevertheless dotted with regional magnetic fields strong enough to be detected from orbit. Did the Moon once have an intrinsic global field that magnetized parts of the crust but has since decayed away? Adding to the puzzle, many of these magnetic anomalies are accompanied by enigmatic optical anomalies known as lunar swirls, which may arise as a result of local variations in space weathering—the poorly understood processes by which the optical properties of airless bodies change over time. Here I will show that we can use swirls to tell us about: 1) the structure of near surface magnetic fields and the characteristics of the underlying magnetic sources; and 2) the optical effects of solar wind weathering and the resulting systematic latitudinal variation in the color of the Moon. These results have implications for the origins of the Moon's crustal magnetic anomalies, the nature of space weathering processes, and the way spectral observations are interpreted across the lunar surface.

Location : Salle conférence du bâtiment 4