This view of Saturn’s moon Enceladus narrowly above the planet’s ring plane was captured by the narrow-angle camera of NASA’s Cassini spacecraft on 29 July 2015 at a distance of approximately 630,000 miles (1.0 million kilometres) from Enceladus. Enceladus is subject to forces that heat a global ocean of liquid water under its icy surface, resulting in its famous south polar water jets which are just visible below the moon’s dark, southern limb. Image credit: NASA/JPL-Caltech/Space Science Institute.Although Enceladus and Saturn’s rings are largely made up of water ice, they show very different characteristics. The small ring particles are too tiny to retain internal heat and have no way to get warm, so they are frozen and geologically dead. Enceladus, on the other hand, is subject to forces that heat its interior to this very day. This results in its famous south polar water jets, which are just visible below the moon’s dark, southern limb, along with a sub-surface ocean.
Recent work by Cassini scientists suggests that Enceladus (313 miles or 504 kilometres across) has a global ocean of liquid water under its surface. This discovery increases scientists’ interest in Enceladus and the quest to understand the role of water in the development of life in the solar system.
This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on 29 July 2015.
The view was acquired at a distance of approximately 630,000 miles (1.0 million kilometres) from Enceladus and at a Sun-Enceladus-spacecraft, or phase angle of 155 degrees. Image scale is 4 miles (6 kilometres) per pixel.
Researchers have revealed the pH of water spewing from geyser-like plumes on Saturn’s moon Enceladus. Their findings are an important step toward determining whether life could exist, or could have previously existed, on the sixth planet’s sixth-largest moon.
In this image from NASA’s Cassini spacecraft we see a crater duo on Saturn’s 698-mile-wide moon Dione. The upper of the pair, named Italus, is overprinted on a grouping of ancient troughs called Petelia Fossae. The lower crater, Caieta, sits atop a feature named Helorus Fossa. Fossae on Dione are believed to be tectonic features.
Saturn’s 698-mile-wide moon Dione crosses the face of the giant planet in a phenomenon known as a transit. Transits play an important role in astronomy and can be used to study the orbits of planets and their atmospheres, both in our solar system and in others. By carefully observing and timing transits, scientists can more precisely determine the orbital parameters of planetary moons.
