In September 2017, a new iceberg calved from Pine Island Glacier—one of the main outlets where the West Antarctic Ice Sheet flows into the ocean. Just weeks later, the berg named B-44 shattered into more than 20 fragments. On December 15, 2017, the Landsat 8 Earth-orbitng satellite took this image of the broken berg. An area of relatively warm water, known as a polyna, has kept the water ice free between the iceberg chunks and the glacier front. The polynya’s warm water could have caused the rapid breakup of B-44.