If it gets stuck near South Georgia Island, that could make it hard for penguin parents to feed their babies and some young could starve.

Measuring roughly 1,350 square miles (3,500 square kilometers) across, A23a is the world's largest and oldest iceberg according to AFP News. Its imposing size and slow, steady movement have captivated oceanographers and researchers alike, though predicting its exact path has proven difficult due to the unpredictable forces of ocean currents.

The trillion-ton slab of ice that scientists call a "megaburg" broke off from the Antarctic’s Filchner Ice Shelf in 1986. Scientists catalogued it under the name A23a. It was stuck at sea for decades but confirmed to be moving again more than a year ago.