What hidden realms lie beneath our feet? In this week's science news, geologists uncovered a series of "sunken worlds" hidden deep within Earth's mantle that they say shouldn't be there. The buried blobs appear to be chunks of our planet's ancient crust, but scientists can't figure out how they got there.
Moving closer to the surface, an enormous reservoir of groundwater — twice the size of Lake Mead, the largest reservoir in the U.S. — has been discovered in the rocks of the Oregon Cascades.
