Task 1: Laboratory study of lunar rocks

We are studying both the intrinsic magnetic properties of lunar rocks and their paleomagnetic record. The study materials are samples collected during the Apollo missions, as well as lunar meteorites.

The intrinsic magnetic properties tell us what kind of magnetic minerals are present in lunar rocks, and in what amount. It also gives information about the paleomagnetic recording potential of these rocks. The paleomagnetic work aims at extracting information about the intensity (and tentatively direction) of the magnetic fields present at the surface of the Moon when the rocks formed.

All together this work aims at clarifying the time evolution of the intensity of the lunar surface magnetic field with time.

A wealth of paleomagnetic data have already been acquired since the return of the Apollo samples in the 1970’s (see Weiss and Tikoo, 2014). One focus of this project is to conduct a simple but exhaustive study of the whole Apollo rock collection, using instruments developed specifically for this task. A second goal is to conduct detailed laboratory paleomagnetic study of selected lunar rocks, in particular young rocks that will allow to constrain the decline and shut-off of the lunar dynamo.

Participants are J. Gattacceca, M. Uehara, P. Rochette, Y. Quesnel, B. Weiss, E. Lima, L. Baratchart, J. Leblond, S. Chevillard.

Weiss, B.P. and Tikoo, S. (2014), The lunar dynamo, Science, 346, 6214, doi:10.1126/science.1246753