A Manhattan-sized ice island just broke free from Greenland

A huge section of Greenlands Petermann Glacier has snapped off, forming an ice island about the size of Manhattan. Satellites watched cracks spread rapidly before the 76-square-kilometer slab finally broke free on August 4. It is the glaciers biggest calving event since 2012, and scientists say two even larger pieces could eventually follow. The rare Arctic iceberg will now be tracked as it drifts, breaks apart, and potentially affects shipping routes.