NASA/JPL/Space Science Institute
A view of Saturn's moon Phoebe, taken during the Cassini spacecraft's June 11, 2004 flyby.
New images of Saturn's outer moon Phoebe reveal a complex and puzzling chunk of ice and rock that was likely leftover from the beginnings of the solar system.
NASA's Cassini spacecraft snapped the images a little over a week ago as it neared its main destination, Saturn. The probe will soon begin a four-year mission to explore the dazzling ringed planet and many of its 31 moons, including the biggest, Titan.
Before Cassini's June 11 flyby, astronomers didn't know much about Phoebe. They knew it was in a distant orbit around Saturn and traveling in the opposite direction from the planet's other moons. They also knew it was round, lumpy and contained some water ice. But as NPR's Richard Harris reports, the findings released today show that Phoebe isn't just an asteroid captured by Saturn's gravity eons ago, but a geologically complex and interesting moon.