NASA’s Cassini spacecraft zoomed by Saturn’s icy moon Enceladus on 14 October 2015, capturing this stunning image of the moon’s north pole. A companion view from the wide-angle camera shows a zoomed out view of the same region for context. Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but high-resolution Cassini images show a landscape of stark contrasts. Thin cracks cross over the pole — the northernmost extent of a global system of such fractures. Before this Cassini flyby, scientists did not know if the fractures extended so far north on Enceladus. North on Enceladus is up. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera. Image credit: NASA/JPL-Caltech/Space Science Institute.NASA’s Cassini spacecraft has begun returning its best-ever views of the northern extremes of Saturn’s icy, ocean-bearing moon Enceladus. The spacecraft obtained the images during its 14 October flyby, passing 1,142 miles (1,839 kilometres) above the moon’s surface. Mission controllers say the spacecraft will continue transmitting images and other data from the encounter for the next several days.
Scientists expected the north polar region of Enceladus to be heavily cratered, based on low-resolution images from the Voyager mission, but the new high-resolution Cassini images show a landscape of stark contrasts. “The northern regions are crisscrossed by a spidery network of gossamer-thin cracks that slice through the craters,” said Paul Helfenstein, a member of the Cassini imaging team at Cornell University, Ithaca, New York. “These thin cracks are ubiquitous on Enceladus, and now we see that they extend across the northern terrains as well.”NASA’s Cassini spacecraft spied this tight trio of craters as it approached Saturn’s icy moon Enceladus for a close flyby on 14 October 2015. The craters, located at high northern latitudes, are sliced through by thin fractures — part of a network of similar cracks that wrap around the snow-white moon. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on 14 October at a distance of approximately 6,000 miles (10,000 kilometres) from Enceladus. Image scale is 197 feet (60 metres) per pixel. The image was taken with the Cassini spacecraft narrow-angle camera using a spectral filter which preferentially admits wavelengths of ultraviolet light centered at 338 nanometers. Image credit: NASA/JPL-Caltech/Space Science Institute.In addition to the processed images, unprocessed, or “raw,” images are posted on the Cassini mission website.
Cassini’s next encounter with Enceladus is planned for 28 October, when the spacecraft will come within 30 miles (49 kilometres) of the moon’s south polar region. During the encounter, Cassini will make its deepest-ever dive through the moon’s plume of icy spray, sampling the chemistry of the extraterrestrial ocean beneath the ice. Mission scientists are hopeful data from that flyby will provide evidence of how much hydrothermal activity is occurring in the moon’s ocean, along with more detailed insights about the ocean’s chemistry — both of which relate to the potential habitability of Enceladus.This view from NASA’s Cassini spacecraft shows battered terrain around the north pole of Saturn’s icy moon Enceladus. Craters crowd and overlap each other, each one recording an impact in the moon’s distant past. The moon’s north pole lies approximately at the top of this view from Cassini’s wide-angle camera. A companion view from the narrow-angle camera shows the pole at a resolution about ten times higher. North on Enceladus is up. The image was taken in visible light by Cassini on 14 October 2015. Image credit: NASA/JPL-Caltech/Space Science Institute.Cassini’s final close Enceladus flyby will take place on 19 December, when the spacecraft will measure the amount of heat coming from the moon’s interior. The flyby will be at an altitude of 3,106 miles (4,999 kilometres).
Similar in many ways, Saturn’s moons Tethys and Rhea (left and right, respectively) even share a discoverer: Giovanni Cassini, namesake of the NASA spacecraft that captured this view. Although somewhat different in size, Rhea (949 miles across) and Tethys (660 miles) are both composed largely of ices and are generally thought to be geologically inactive today.
Chariklo is the largest confirmed centaur, a minor planet orbiting the Sun between Saturn and Uranus. In 2014, two rings were discovered around Chariklo. Soon after, scientists discovered that rings likely exist around another centaur, Chiron, but the origin of these rings remained a mystery — until now.
