Saturn’s Secrets Revealed:
The 40th Anniversary Of The Voyager 1 Flyby

NASA illustration of Voyager 1

In 1980, Voyager 1 became only the second space probe to ever fly past the planet Saturn. Voyagers 1 and 2 were twin space probes that were launched in 1977. They were designed for what was to be called the grand tour of the outer planets. A rare alignment of planets that only occurs every 175 years would allow a space probe to visit all four outer gas giants. Both Voyager 1 and Voyager 2 would fly past Jupiter and Saturn. Voyager 2 would continue on to Uranus in 1986, and finally Neptune in 1989.

On September 1, 1979, Pioneer 11 became the first space probe to fly past Saturn. The cameras and instruments on this probe were not as sophisticated as those on Voyager however. It would be up to the Voyager probes to truly reveal in detail the majesty of Saturn and its moons. On November 12, 1980, Voyager 1 made a close approach of Saturn, coming within 124,000 kilometers of Saturn’s cloud-tops. The probe confirmed that the majority of Saturn’s atmosphere is made up of Hydrogen gas. Voyager 1 measured the rotation of Saturn at 10 hours, 39 minutes. Hundreds of photos of Saturn and its ring system were taken. The rings were determined to be made almost entirely of water ice, with a small amount of rocky material.

False Color Voyager Image of Saturn

Voyager 1 Image of Titan

In addition to studying Saturn up close, Voyager 1 also photographed and gathered data on the many moons of Saturn. Of particular interest was Saturn’s largest moon, Titan. Titan is unique in the solar system as being the only moon with a thick, substantial atmosphere.The atmosphere of Titan is largely made up of nitrogen; with methane and ethane clouds and nitrogen-rich organic smog. In order to make a close fly-by of Titan, Voyager 1 would be unable to continue to Uranus and Neptune. The Titan encounter was considered very important by the mission scientists. If Voyager 1 had failed to acquire the Titan data, Voyager 2 would have been rerouted to Titan and would not have continued on to Uranus and Neptune.

Titan’s surface taken by Huygen’s Titan Lander Probe

After the successful encounter with Saturn and its moon Titan, Voyager 1 would continue on a journey to the heliopause. The heliopause is the theoretical boundary where the Sun’s solar wind is stopped by the interstellar medium. Here, the solar wind’s strength is no longer great enough to push back the stellar winds of the surrounding stars. On August 25, 2012, Voyager 1 became the first spacecraft to cross the heliopause and enter the interstellar medium.

Other spacecraft would also visit Saturn. Voyager 2 would fly past in August 1981. The Cassini spacecraft went into orbit around Saturn on July 1, 2004. Cassini would continue to send back pictures and data until the mission ended on September 15, 2017, when the probe’s trajectory took it into Saturn’s upper atmosphere where it burned up. The Cassini spacecraft also delivered the Huygens Titan lander probe. Huygens became the first spacecraft to land on Titan on January 14, 2005, giving us our first detailed views of the surface of this mysterious moon.

It was the Voyager 1 spacecraft in November 1980 though that really paved the way for these future missions by giving us our first close-up look at Saturn, its rings and its moons. A true milestone mission in space exploration.

Saturn and Moons
Voyager image taken November 3, 1980 of Saturn and two of its moons: Tethys and Dione
enterprise arriving paris air show 1983