On July 14, the Cassini spacecraft conducted its closest flyby yet, coming within 175 kilometers (109 miles) from the surface of the wrinkled, icy moon, Enceladus.
During Cassini's first flyby of Enceladus, a tenuous atmosphere was detected in magnetic field data, which may imply internal activity. This atmosphere may help explain the source of Saturn's outermost E ring.
The icy surface of Enceladus appears to have similarities to both Europa and Ganymede -- two prominent icy satellites of Jupiter. Both Europa and Ganymede are thought to have subsurface water layers or "oceans," so the similarities with Enceladus are intriguing.