... Liquid Sea on Saturns Titan . ... Credit: Cassini Radar Mapper , JPL , ESA , NASA Explanation: What is this vast dark region on Titan? ... The region was imaged earlier this month when the robotic Cassini spacecraft swooped past Saturn's cloudy moon and illuminated part of it with radar. The dark region in the above image reflected little radar, an effect expected were the dark surface relatively flat, as expected for a liquid. ... Publications with keywords: cassini spacecraft - Titan . ...