Flying low over some of the most dramatic landscapes on the planet, a cadre of scientists and pilots have been measuring changes in Alaskan glaciers as part of NASA’s Operation IceBridge for almost a decade. The team has seen significant change in ice extent and thickness over that time. Data from the mission was used in a 2015 study that put numbers on the loss of Alaskan glaciers: 75 billion tons of ice every year from 1994 to 2013. Last summer, Chris Larsen and Martin Truffer, both of the University of Alaska Fairbanks, flew with University of Arizona’s Jack Holt and University of Texas student Michael Christoffersen.