Visit to a frozen moon

Saturn's Helene is a strange moon. Covered with ice, marked by huge areas that look like remains of ancient iceflows, and stuck in the same orbit as two other moons (apparently bound gravitationally to "big sister" Dione), it's a world of mystery. Now the Cassini probe has given us our best look yet, and scientists will soon be able to assemble a map of Saturn's "ice queen."