Because of the shading of wood leaf layers and litter fall, soil evaporation and the range of soil moisture contents changing were small under forest canopy.

His strange habit makes sense when you consider that he's an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road.

Using large deployable surfaces to increase the drag on these objects so they fall to Earth rapidly is one possible solution to the space litter problem.