Ultima Thule, the relatively tiny object in the outer solar system, is now the farthest cosmic body to be reached by humans. We hear from the lead scientist behind the farthest flyby ever.

NASA’s New Horizons spacecraft captured this high-resolution enhanced color view of Pluto on July 14, 2015.

Meet the authors of a new tell-all book that reveals the incredible story behind the little spacecraft that was the first to explore Pluto.