关于这张图
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. The mountain ridge seen in the south in this image is part of the undulating mountain belt that circumscribes this region. This view looks toward the leading side of Enceladus (313 miles, 504 kilometers across). N…
