Saturn's moon Enceladus, covered in snow and ice, resembles a perfectly packed snowball in this image from NASA's Cassini mission. Cassini has imaged Enceladus many times throughout its mission, discovering a fractured surface and the now-famous geysers that erupt icy particles and water vapor from fractures crossing the moons' 200-mile-wide (300-kilometer-wide) south polar terrain.
... During this flyby, Cassini will image the north polar regions of Enceladus -- something not possible in the first years of the mission, when the moon's north pole was in darkness. Scientists are eager to search for indications of whether the north polar region might have been geophysically active at some time in the past.
