Cassini Spacecraft's 20-Year Mission Ends With A Fiery Explosion Into Saturn

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Saturn captured from 20 degrees above the ring plane (Photo Credit: NASA/JPL)

On September 15, 2017, Cassini’s 19 year, 11 month, 0 day, 3 hour, 12 minute and 46 second long mission ended with a plunge into Saturn, the planet it had been orbiting for 13 years. The fiery demise was not accidental, but the result of a well-orchestrated plan to ensure that the spacecraft, which was running out of rocket propellant, would not crash and pollute Saturn’s pristine moons.

Red Arc-shaped streaks discovered on Saturn’s ice-rich moon Tethys (Image Credit: JPL.NASA.gov

The Grand Finale, as it was called, was set in motion in April 2017, when Cassini was put on an impact course with Saturn through a series of 22 orbits between the planet and its rings. The never-before explored areas provided researchers with additional information that was too risky to obtain earlier in the mission. This included detailed maps of Saturn’s gravity and magnetic fields, which will enable scientists to calculate its rotation speed. Researchers were also able to get a better estimate of the amount of material in the rings, data that may help them better understand how the planet was formed. The close encounters also allowed Cassini to capture incredibly detailed images of Saturn’s rings and clouds.

Image Credit: NASA.gov

Launched on October 15, 1997, the Cassini orbiter together with the European Space Agency’s Huygens probe, spent six months collecting data on Jupiter before entering Saturn’s orbit on June 30, 2004. Before the year ended, Cassini had not only conducted a series of flybys of some of the planet’s 60+ moons, but also released the Huygens probe on Saturn’s largest moon, Titan, to collect data on its atmosphere. This was the first landing on a moon, other than our own, as well as the farthest one ever made by any human-made spacecraft. Though Huygen’ mission ended there, Cassini was just getting started.

Geysers on Enceladus spray water vapor and ice mixed with organic molecules into space (NASA/JPL-Caltech/Univ. Arizona/Univ. Idaho)

While its original task to explore the Saturn system was scheduled to end in 2008, the spacecraft was doing so well that its mission was extended twice, once for two years, and then again for seven years. In fact, the only reason researchers decided to cut short the spacecraft’s “life” was because it was running out of fuel.

Ligiea Mare is the second largest body of liquid on Saturn's moon Titan (Photo Credit: NASA/JPL-Caltech/ASI/Cornell)

The additional years enabled Cassini to observe almost two of Saturn’s 7-year long seasons and provide researchers the first detailed data of the planet and its family of moons. These include the methane-rich seas and lakes that cover close to two-thirds of Titan’s surface, as well as the erupting geysers on Enceladus. This is the first time hydrothermal activity has been observed outside Earth. During its lifetime, Cassini traveled over 4.9 billion miles and conducted 162 flybys of Saturn’s moons. All in all, the information collected by Cassini has resulted in 3,948 science publications.

Glowing bands appear at the poles where the solar wind slams into Saturn’s magnetosphere (Photo Credit: NASA/JPL/University of Arizona)

While Cassini may be gone, its contribution to planetary science will be remembered forever. As Mike Watkins, director of NASA’s Jet Propulsion Lab, succinctly puts it, “One of the greatest legacies of the mission is not just the scientific discoveries it makes, and what you learn about, but the fact that you make discoveries that are so compelling that you have to go back. We will go back and fly through the geysers of Enceladus, we will go back and look at Titan, because the Cassini findings are just groundbreaking.”

Resources: Saturn.jpl.nasa.gov, nature.com,nasa.gov

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290 Comments
  • jeffThursday, May 30, 2019 at 6:35 am
    The best!
    • aar0nburr_s1r
      aar0nburr_s1rMonday, April 15, 2019 at 6:22 pm
      wow cool
      • SSunday, February 10, 2019 at 7:41 pm
        To bad I wish they landed on satern safely
        • ssssssssssssMonday, December 3, 2018 at 10:35 am
          i think cassini was a person lol
          • SQUIDWARDFriday, October 5, 2018 at 10:45 am
            this is weird topic but sad and cool
            • awesome dudeTuesday, October 2, 2018 at 9:42 am
              not cool but sad
              • spiders2
                spiders2Friday, September 28, 2018 at 8:49 am
                Cool
                • science kidWednesday, September 26, 2018 at 1:36 pm
                  the water idea i think is cool but the water would freeze up because the tempature in space can drop to like -8000000000 celcius its crazy and when water freezes it losses all the oxegen in it and there is not enough water on earth to fill its atmesphere with oxegen that and i dont think saturn even has a feild that keeps gasses and chemicals in it so even if the oxegen made it there it would just fly away and get burnt up by a star but... i still think thats a good idea.
                  • makesaturnliveThursday, August 30, 2018 at 6:51 am
                    what if they were to put some water on one it has oxigen so we might be able to make satern livable
                    • ajg16
                      ajg16Saturday, August 25, 2018 at 1:23 pm
                      So we littered on saturn? (Also wow they discovered alot!)