In 2016 and 2017, a hole of open water, called a polynya, appeared in the winter ice of the Weddell Sea in Antarctica. It eventually grew to about 19,000 square miles; roughly twice the size of Vermont. Though polynyas are not unusual, this large and frequent of a hole was a great opportunity for scientists to figure out why, exactly, these holes were appearing. A team from the University of Washington explored the hole with a combination of robots, radio equipment and seals with antennas stuck to their heads. The team found that, in order for a polynya to occur,...