"While our results are still very new, our thinking is that the mercury detected by Lamp from the Grail site might be related to an enhancement at the poles caused by mercury atoms generally hopping across the surface and eventually migrating toward the cold polar regions, " said Kurt Retherford, the chief scientist for Lamp.
One of LRO's instruments, the Lyman Alpha Mapping Project (Lamp), detected enhanced concentrations of mercury and atomic hydrogen in the cloud from the demise of the twin spacecraft.