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.
On Wednesday, 28 October 2015, NASA’s Cassini spacecraft will take the deepest dive ever through the plume of ice, water vapour and organic molecules spraying from the south polar region of Saturn’s moon Enceladus. Scientists hope this close flyby will shed light on what’s happening beneath the moon’s icy surface. With a global ocean and likely hydrothermal activity, could Enceladus have the ingredients needed to support simple forms of life?
Two tiny moons of Saturn, almost lost amid the planet’s enormous rings, are seen orbiting in this Cassini probe image. Pan, visible within the Encke Gap near lower-right, is in the process of overtaking the slower Atlas, visible at upper-left.
Astronomers using NASA’s Hubble Space Telescope have imaged what may be water vapour plumes erupting 125 miles (200 kilometres) off the surface of Jupiter’s moon Europa. Europa has a huge global ocean containing twice as much water as Earth’s oceans, but it is protected by a layer of extremely cold and hard ice of unknown thickness.
