In this article the author discusses the studies by C. A. Dwyer and colleagues and M. Le Bars and colleagues, which suggests the ancient lunar dynamo as mechanically driven. He says that the two studies evaluate the motions of fluid, which is driven by the fast spin of Moon's fluid core to its solid mantle. He adds that through frictional coupling between the core and mantle as well as kinetic energy, the authors note likely occurence of dynamo action.