In 2004, NASA’s interplanetary explorer slipped into orbit around iconic, ringed Saturn. These were the waning days of that planet’s northern winter, and the north pole was a surprising, Neptunian blue. Distant, icy moon Enceladus was still thought to be like most other icy moons — cold, cratered, and small. But over the last nine years, Cassini’s travels through the Saturnian system have produced both startling discoveries and overwhelmingly beautiful images. Now, as the seasons on Saturn shift and summer comes to the north, we know that Enceladus isn’t another placid, frozen moons. It’s one of the most exciting places in the solar system, and, along with sibling moon Titan, now sits atop the list of places to search for extraterrestrial lifeforms.
In fact, most of what we’ve learned from Cassini about Saturn, its rings, and its moons is pretty different from what we expected, and that trend seems unlikely to fade.