Mountains of ice
, some 11,000 feet tall. A gorge five times deeper than the Grand Canyon. And active, young surfaces, barely pockmarked by craters. Those are just a few of the surprising features that the New Horizons spacecraft beamed back this week, after its flyby of Pluto and its moons. Cathy Olkin, deputy project scientist for the mission, says Pluto and Charon are far different than she imagined, revealing an unexpected, puzzling variety of terrains. “Welcome to the outer solar system,” she says. Olkin joins Jim Green, NASA’s head of planetary science, to discuss the latest findings.