Antarctic Glacier Calves 280-Square-Mile Iceberg

This week, a European Earth-observing satellite confirmed that a large iceberg broke off of Antarctica's Pine Island Glacier. The rift that led to the new iceberg was discovered in October 2011 during NASA's Operation IceBridge flights over the continent. Seeing the rift grow and form a 280-square-mile ice island gave researchers an opportunity to gather data that promises to improve our understanding of how glaciers calve.