4500 Kilometers Above Dione . ... Credit Copyright: Cassini Imaging Team , SSI , JPL , ESA , NASA Explanation: What does the surface of Saturn's moon Dione look like? To find out, the robot Cassini spacecraft currently orbiting Saturn flew right past the fourth largest moon of the giant planet earlier this month. ... Fractures, grooves, and craters in Dione's ice and rock are visible. ... Many of the craters have bright walls but dark floors , indicating that fresher ice is brighter. ...