Cassini’s two decade run as Saturn’s most famous roommate has come to an end.
NASA announced on Sept. 15 that the longtime spacecraft orbiting Saturn has deliberately plunged into Saturn’s atmosphere, closing it’s 20-year run in space while ensuring that the planet’s two moons—Titan and Enceladus—remain in pristine condition for possible future exploration.
As of 7:55 a.m. EDT Sept. 15 the spacecraft lost contact with Earth.
“This is the final chapter of an amazing mission but it’s also a new beginning,” Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate at NASA Headquarters in Washington, said in a statement. “Cassini’s discovery of ocean worlds at Titan and Enceladus changed everything, shaking our views to the core about surprising places to search for potential life beyond Earth.”
Since 2010, Cassini has been part of a seven-year mission extension where it completed several moon flybys while observing seasonal changes on Saturn and Titan. Last April, Cassini was placed on an impact course that included five months of dives—a series of 22 orbits passing between the planet and its rings.
These dives included skirting the very inner edge of Saturn’s rings, while also at other times skimming through the outer edges of the atmosphere. Each of the final orbits take about six-and-a-half days to complete, with the spacecraft reaching top speed of between 75,000 and 78,000 miles per hour.
The final phase of this mission—called the Grand Finale—gave NASA a closer observation of Saturn and its rings than ever before, as Cassini dived through an approximately 1,200-mile-wide gap between Saturn and its ring.
“It’s a bittersweet but fond, farewell to a mission that leaves behind an incredible wealth of discoveries that have changed our view of Saturn and our solar system and will continue to shape future missions and research,” Michael Watkins, director of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, which manages the Cassini mission for the agency, said in a statement.
Cassini originally launched on Oct. 15 1997 and entered orbit around Saturn in 2004. NASA extended Cassini’s prime mission twice after the original four-year mission was completed. Some of its key discoveries include observing the global ocean with indications of hydrothermal activity within Enceladus and liquid methane in the seas of Titan.
Cassini spent a total of 13 years in Saturn’s orbit after a seven-year journey from Earth that included flybys of Venus and Jupiter.
NASA is taking lessons learned during Cassini’s life span and applying them to plan for NASA’s Europa Clipper mission, which is expected to launch and explore Jupiter in the next decade.
Over the next few decades, scientists are hoping to return to the Saturn system for follow ups on many of Cassini’s discoveries, including drifting on the methane seas of Titan and flying through the Enceladus plume to collect and analyze samples for signs of biology.
“Things never will be quite the same for those of us on the Cassini team now that the spacecraft is no longer flying,” Linda Spilker, Cassini project scientist at JPL, said in a statement. “But, we take comfort knowing that every time we look up at Saturn in the night sky, part of Cassini will be there, too.”