In Siberia’s Yana Highlands, a chunk of land roughly the shape of a giant stingray has been sinking down into a very large pit. Called the Doorway to the Underworld, the Batagay Megaslump (also known as the Batagaika Crater) is 200 acres and continues to widen. Scientists have known for a while that the permafrost crater has been continually melting and growing, but the expansion is even faster than they’d realized. In a new study, scientists were finally able to see and measure the crater’s staggering accelerated expansion. The team…