"We don't know exactly what they are or what material is creating the patterns we have uncovered," researcher Thomas Schouten said.

Researchers have created a simulation that maps underground water on a continental scale. The result of three years' work studying groundwater from coast to coast, the findings plot the unseen path ...

A recent push by the NASA Surface Water and Ocean Topography (SWOT) satellite to shine a light into that darkness has been illuminating, to say the least.