NASA’s Cassini spacecraft has begun transmitting data and images from the mission’s final close flyby of Saturn’s active moon Enceladus. Cassini passed Enceladus at a distance of 3,106 miles (4,999 kilometres) on Saturday, 19 December at 5:49pm GMT (12:49pm EST).
“This final Enceladus flyby elicits feelings of both sadness and triumph,” said Earl Maize, Cassini project manager at JPL. “While we’re sad to have the close flybys behind us, we’ve placed the capstone on an incredible decade of investigating one of the most intriguing bodies in the solar system.”Cassini will continue to monitor activity on Enceladus from a distance, through the end of its mission in September 2017. Future encounters will be much farther away — at closest, more than four times farther than this latest encounter.
This was the 22nd Enceladus encounter of Cassini’s mission. The spacecraft’s discovery of geologic activity there, not long after arriving at Saturn, prompted changes to the mission’s flight plan to maximise the number and quality of flybys of the icy moon.“We bid a poignant goodbye to our close views of this amazing icy world,” said Linda Spilker, the mission’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “Cassini has made so many breathtaking discoveries about Enceladus, yet so much more remains to be done to answer that pivotal question, ‘Does this tiny ocean world harbour life?'”
After revealing Enceladus’ surprising geologic activity in 2005, Cassini made a series of discoveries about the material gushing from warm fractures near its south pole. Scientists announced strong evidence for a regional subsurface sea in 2014, revising their understanding in 2015 to confirm that the moon hosts a global ocean beneath its icy crust.
In this image from NASA’s Cassini spacecraft, Saturn’s moon Dione reveals its past via contrasts. The features visible here are a mixture of tectonics — the bright, linear features — and impact cratering — the round features, which are spread across the entire surface.
Researchers at Kobe University have used computer models to reveal that Saturn’s F Ring and its shepherd satellites are a natural outcome of the final stage of the planet’s satellite system. This new finding is expected to help elucidate the formation of satellite systems both within and outside our solar system.
Voyager 2 made its closest approach to Saturn 35 years ago — on 25 August 1981. What the Voyagers revealed at the planet was so phenomenal that, just one year later, a joint American and European working group began discussing a mission that would carry on Voyager’s legacy at Saturn.