Early Lunar Magnetism

作者：Ian Garrick‐Bethell, B. P. Weiss, David L. Shuster, J. Buz · 发表于：Science · 年份：2009 · DOI：10.1126/science.1166804 · 被引用次数：181 · 研究领域：Planetary Science and Exploration、Astro and Planetary Science、Geomagnetism and Paleomagnetism Studies

It is uncertain whether the Moon ever formed a metallic core or generated a core dynamo. The lunar crust and returned samples are magnetized, but the source of this magnetization could be meteoroid impacts rather than a dynamo. Here, we report magnetic measurements and 40Ar/39Ar thermochronological calculations for the oldest known unshocked lunar rock, troctolite 76535. These data imply that there was a long-lived field on the Moon of at least 1 microtesla approximately 4.2 billion years ago. The early age, substantial intensity, and long lifetime of this field support the hypothesis of an ancient lunar core dynamo.