It's been a busy year for Cassini, making observations of Hyperion and Dione, before discovering evidence of a global ocean beneath the moon Enceladus' icy surface. Now the probe is back at Enceladus for another flyby, completing its deepest-ever dive through the body's icy plume.

The spacecraft completed its flyby at around 8:22 am PDT (11:22 am EDT), passing just 30 miles (49 km) above the Saturnian moon's southern polar region. Following the encounter, NASA successfully established two-way communications with the probe, and plans to begin downloading recorded data later today. The process is expected to take between 24 and 48 hours to complete.

Cassini launched back in 1997 and has been orbiting around Saturn since 2004, studying numerous aspects of the planet, from its rings to its magnetic field. It's now studying the moon Enceladus, with a particular focus on the huge plume thought to be jetting out from a subsurface ocean, and consisting of ice, water vapor and organic molecules.

While the flyby isn't designed to detect life in the towering icy jet, it's hoped that the recorded data will provide insights into the habitability of the ocean beneath the body's surface.

It's also hoped that other mysteries will be solved, such as the exact nature and structure of the plume – whether it's composed of column-like jets or curtain-shaped eruptions – and exactly how much material is being erupted.

Today's flyby is Cassini's penultimate encounter with Enceladus, with a final targeted look at the body planned for December 19. On that occasion, the probe won't be nearly as close to the moon, passing it at a distance of 3,106 miles (4,999 km).

Source: NASA