“Antarctic Edge: 70 South,” opening April 17, is an extraordinarily beautiful and important documentary about the dedicated scientists who’ve clocked the deterioration of the Antarctic ice sheet and tracked consequential climate change around the globe for the past 20 years. Filmmaker Dena Seidel had unlimited access to scientific data and personnel, both in Antarctica, where she filmed extensively and exquisitely, and at Rutgers University in New Jersey, where she heads the school’s Center for Digital Filmmaking. Seidel taps scientists’ unquenchable quest for knowledge and there’s a lot of information to absorb. More poetic than polemical, the film combines a thrilling presentation of natural wonders with amusing glimpses into the lives of the scientists. It’s a convincing call for action to save the planet; if that is still possible. “Antarctic Edge” is this week’s edgy must-see.