What you are seeing is an errupting ice volcano on Enceladus, a moon of Saturn. It is thought that the powerful eruption deposits ice particles in one of Saturn's outer rings. This image was taken by Cassini last week.

ETA I thought I should add this snip to clarify (taken from saturn.jpl.nasa.gov). As an artist, I hear something like "ice volcano" (or its uber-cool techie term "cryovolcanism") and I get inspired, excited, etc. But I don't wish to misinform (the scientist in me):

"At present, it is not clear if the plume particles emanating from the south pole arises because of water vapor escaping from warm ice that is exposed to the surface. Another possibility is that at some depth beneath the surface, the temperatures are hot enough for water to become liquid, which then, under pressure, escapes to the surface like a cold Yellowstone geyser. "

Image credit: NASA/JPL/Space Science Institute.