Scientists have finally discovered what's causing a Switzerland-size hole to repeatedly open up in Antarctica's sea ice.

But this polynya's reappearance is a mystery to scientists ... A mysterious hole larger than Maryland has reappeared in the middle of Antarctica after 42 years. Scientists aren't sure how it ...

This mysterious feature, called a polynya, represents one of the largest ever found in Antarctica. While the polynya itself is temporary, Antarctic cruise passengers traveling through the Weddell ...