Cassini images Enceladus’ south polar jets
NASA’s Cassini orbiter has captured a distant view of the mysterious jets emanating from the south pole of Saturn’s moon Enceladus, a world that likely harbors a subsurface ocean. The jets are believed to be liquid water being vented from the ocean underneath the moon’s icy crust.
Taken April 13, 2017, in visible light by Cassini’s narrow-angle camera, the image shows the jets, backlit by sunlight, streaming from Enceladus’ south pole while the moon itself is lit by reflected Saturnshine.
Cassini captured the image, which has a scale of three miles (five kilometers) per pixel, at a distance of about 502,000 miles (808,000 kilometers) from Enceladus.
North is up in the photograph, and the view shows the Saturn-facing hemisphere of Enceladus, which has a diameter of 313 miles (504 kilometers).
By photographing the jets from a variety of angles and positions, Cassini has collected a treasure trove of data scientists hope will answer many questions about the moon’s underground ocean.
A study published in the journal Nature Astronomy in March 2017 found Enceladus’ south pole to be warmer than expected just a few feet below the icy surface, especially around the prominent tiger-striped fractures.
Heat seems to be especially concentrated around three actively-venting fractures that run across the south pole.
The research team estimated south polar surface ice to be less than three miles (five kilometers) thick.
“Finding temperatures near these three inactive fractures that are unexpectedly higher than those outside them adds to the intrigue of Enceladus,” Cassini Project Scientist Linda Spilker of NASA’s Jet Propulsion Laboratory said at the time. “What is the warm underground ocean really like, and could life have evolved there? These questions remain to be answered by future missions to this ocean world.”
Cassini has two months left until concluding its Grand Finale of dives between Saturn’s innermost ring and the giant planet by plunging into the gas giant’s atmosphere on Sept. 15, 2017.
Images taken by the orbiter during its exploration of Saturn can be found on the imaging team’s homepage at http://ciclops.org.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.