The Pine Island Glacier is a massive flowing river of ice on the western Antarctic ice shelf. And by massive, I mean massive: it's 250 km (150+ miles) long, and has an area of 175,000 square kilometers -- that's bigger than the state of Iowa! Every year, a staggering 79 cubic kilometers (19 cubic miles) of ice drains from this glacier in the ocean, flowing via a tongue of ice floating in the water off the main land. Flying over the glacier on October 14, scientists aboard a NASA DC-8 airplane as part of the IceBridge mission were startled to see a huge crack across the glacier. Flying back over it on October 26, they were able to photograph and measure this huge rift, and found it will almost certainly soon give birth to a huge iceberg. Check out this lovely picture of the ice crack: