A Long-Lived Lunar Core Dynamo

作者：Shea Erin K^*; Weiss Benjamin P; Cassata William S; Shuster David L; Tikoo Sonia M; Gattacceca Jerome; Grove Timothy L; Fuller Michael D

来源：Science, 2012, 335(6067): 453-456.

DOI：10.1126/science.1215359

Paleomagnetic measurements indicate that a core dynamo probably existed on the Moon 4.2 billion years ago. However, the subsequent history of the lunar core dynamo is unknown. Here we report paleomagnetic, petrologic, and Ar-40/Ar-39 thermochronometry measurements on the 3.7-billion-year-old mare basalt sample 10020. This sample contains a high-coercivity magnetization acquired in a stable field of at least similar to 12 microteslas. These data extend the known lifetime of the lunar dynamo by 500 million years. Such a long-lived lunar dynamo probably required a power source other than thermochemical convection from secular cooling of the lunar interior. The inferred strong intensity of the lunar paleofield presents a challenge to current dynamo theory.

• 出版日期2012-1-27