This article is part of Yahoo's 'On This Day' series
When Galileo first saw Saturn’s rings in 1610, the famous astronomer had no idea what they were and described them as ‘ears’ or ‘lobes’ around the planet.
Astronomer Christiaan Huygens first suggested that the structures might be rings in 1655.
The rings are not visible to the naked eye, but only via telescopes, and it was on this day, November 12 in 1980, when the Voyager probe reached Saturn and captured an image of the rings.
In 1977, Nasa launched two space probes to gather data about the solar system’s outer planets: Voyager 1 and 2.
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Flying at nine miles a second, Voyager captured incredible images of the rings in November 1980 - and amazed the scientists studying them.
Linda Spilker, who worked on the Voyager team said, “We thought we would find bland, featureless sheets of material separated by gaps."
Instead, as early as October, the researchers could make out dark streaks within the rings.
"It looked like grooves on a phonograph record," said Spilker. "The rings were just so much more than I had imagined."
The scientists saw more than 100 separate rings, rather than the five or six observable from Earth, and within them moons which caused spirals and waves within the wrings.
Dr Bradford Smith, leader of the Voyager photo-interpretation team, said: "The mystery of the rings, the structure and the mechanism that governs the structure, keeps getting deeper and deeper."
What the twin spacecraft saw of Saturn was so intriguing that a joint American-European group began planning the next mission to Saturn - the Cassini probe - just one year later.
Ed Stone, Voyager project scientist at NASA’s Jet Propulsion Laboratory (JPL) said, "Saturn, like all of the planets the Voyagers visited, was full of exciting discoveries and surprises.
"By giving us unprecedented views of the Saturn system, Voyager gave us plenty of reasons to go back for a closer look."
Launched in 1997, Cassini toured the Saturn system since arriving in 2004 for an up-close study of the planet, its rings and moons.
Cassini provided scientists with a treasure-trove of information on the rings which is still being analysed, before it ran out of fuel and performed a series of daring ‘dives’ in between the rings and Saturn itself.
Cassini spotted ‘ring rain’ - tiny particles which fall from the innermost ring onto the planet at a rate of tonnes per second - and found chemicals including organic molecules within the ‘rain’.
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MORE FROM 'ON THIS DAY'
In 2012, the Voyager probe which blasted off from Earth in 1977 became the first man-made object to leave the Solar System.
It’s twin Voyager 2 crossed the outer edge of the Sun's protective bubble, known as the heliopause, on November 5 2018.
It had blasted off from Earth 16 days before its twin spacecraft, Voyager 1 - but entered the interstellar medium six years after Voyager 1 due to its slower trajectory.
In 2026, NASA plans to launch Dragonfly, a mission to Saturn’s icy moon Titan, photographed in 1979 by Voyager 1.