Snowy Enceladus. As Cassini, this joint NASA/European ESA/Italian Space Agency mission, is now orbiting Saturn in quest of a comprehensive view of the Saturnian world, it has taken this view of Enceladus, one of Saturn's moons. The 270-mile (500 km) wide Enceladus is orbiting relatively near Saturn. Enceladus is a moon akin to Jupiter's Europa and Ganymede, that is that its surface is ice and that ice tectonics and volcanism are active there. The Saturnian moon however is much more snow-covered, and smoothed-looking. This might be due to a geological activity like ice volcanoes, or geysers, or of whatever kind, projecting snow out. This same process is responsible too for something intriguing: Enceladus has been discovered by Cassini like having an extended, thin, ionized water vapor atmosphere. This is not out of the ordinary, as Enceladus was already thought at the origin of Saturn's E ring, a vast, nearly invisible ring lying up to distance of 298,000 mi (480,000 km) from Saturn. The activity of Enceladus might be the equivalent at Saturn of what Io is at Jupiter. Enceladus is the most reflective moon of the solar system. picture NASA/JPL/Space Science Institute