IntroductionSaturn was the most distant of the five planets known to the ancients. In 1610, Italian astronomer Galileo Galilei was the first to gaze at Saturn through a telescope. To his surprise, he saw a pair of objects on either side of the planet. He sketched them as separate circles, thinking that Saturn was triple-bodied. In 1655, Dutch astronomer Christiaan Huygens, using a more powerful telescope than Galileo's, observed that Saturn was surrounded by a thin, flat ring. He proposed the correct explanation for his observations and the regular disappearances and reappearances of Saturn’s ring in 1659 in Systema Saturnium.

    In modern times, Saturn has been revealed in Hubble Space Telescope observations. Pioneer 10 made the first close observations of Saturn, followed by more detail flybys by both Voyager 1 and 2. But no spacecraft have revealed more about Saturn, its rings and moons than the Cassini orbiter and the Huygens probe, which landed in Titan in 2005.

    Significant Events

    Significant Events

    • ~700 BCE: The oldest written records documenting Saturn are attributed to the Assyrians, described the ringed planet as a sparkle in the night and named it "Star of Ninib."
    • ~400 BCE: Ancient Greek astronomers named what they thought was a wandering star in honor of Kronos, the god of agriculture. The Romans later change the name to Saturn, their god of agriculture.
      Galileo's Phases of Venus and Other Planets
      Galileo Galilei's observations that Venus appeared in phases—similar to those of Earth's Moon—in our sky was evidence that Venus orbited the sun and contributed to the downfall of the centuries-old belief that the sun and planets revolved around Earth. Also sketched here are Jupiter, Saturn and Mars. Image Credit: Istituto di Linguistica Computazionale
    • July 1610: Galileo Galilei spots Saturn's rings through a telescope, but mistakes them for a "triple planet."
    • 1655: Christiaan Huygens discovers Saturn's rings and its largest moon, Titan.
    • 1675: Italian-born astronomer Jean-Dominique Cassini discovered a "division" between what are now called the A and B rings.
    • Sept. 1, 1979: Pioneer 11 was the first spacecraft to reach Saturn. Among Pioneer 11's many discoveries are Saturn's F ring and a new moon.
    • 1980 and 1981: In its 1980 flyby of Saturn, Voyager 1 reveals the intricate structure of the ring system, consisting of thousands of ringlets. Flying even closer to Saturn in 1981, Voyager 2 provided more detailed images and documents the thinness of some of the rings.
    • July 1, 2004: NASA's Cassini spacecraft becomes the first to orbit Saturn, beginning a decade-long mission that revealed many secrets and surprises about Saturn and its system of rings and moons.
    • Jan. 14, 2005: The European Space Agency's Huygens probe is the first spacecraft to make a soft landing on the surface of another planet's moon - Saturn's giant moon Titan. The probe provided a detailed study Titan's atmosphere during a 2 hour and 27 minute descent and relayed data and images from Titan's muddy surface for another hour and 10 minutes.
    • Sept. 17, 2006: Scientists discover a new ring. The new ring coincides with the orbits of Saturn's moons Janus and Epimetheus. Images obtained during the longest solar occultation of Cassini's four-year mission revealed the ring. During a solar occultation, the Sun passes directly behind Saturn causing the rings to be brilliantly backlit. Usually, an occultation lasts only about an hour, but in this instance it lasted 12 hours.
    • 2009: NASA’s Spitzer Space Telescope reveals the presence of a gigantic, low density ring associated with Saturn’s distant moon Phoebe.
    • Sep. 15, 2017: Cassini ends a 13-year orbital mission with a spectacular, planned plunge into Saturn’s atmosphere—sending science data back to the last second. Cassini’s final five orbits enabled scientists to directly sample Saturn’s atmosphere for the first time

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    Explore in 3D

    Explore in 3D—Eyes on Cassini

    The Cassini mission launched in 1997 and spent seven years traveling to Saturn, arriving in 2004. Cassini is the first spacecraft to orbit Saturn, and has provided a treasure trove of data and images of the entire Saturnian system. Now you can ride onboard the spacecraft throughout the entire 20-year mission mission using NASA’s free software on your Mac or PC.

    Eyes on Cassini ›

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