History of Discoveries

Early Days

The oldest written records documenting Saturn are attributed to the Assyrians. Around 700 B.C., they described the ringed planet as a sparkle in the night and named it "Star of Ninib."

The Assyrians, who occupied what is now Iraq, prospered between 1400 and 620 B.C. They incorporated the culture of the Babylonians, a civilization with a keen eye for astronomy. Historians believe that as early as 3000 B.C. the Babylonians recognized major constellations and eventually developed a calendar of astronomical events.

Artists of the Roman God, Saturn

A few centuries later, in 400 B.C. the ancient Greeks named what they thought was a wandering star in honor of Kronos, the god of the harvest. Kronos (sometimes spelled Cronos or Cronus), youngest of the Titans, was the father of Zeus. When the Romans adopted the Greek gods for their own, they renamed Kronos Saturnus, and renamed Zeus Jupiter.

Just as Kronos had been, Saturnus was the god of agriculture. Every December, the Romans held a seven-day festival called Saturnalia in his honor, ancient Rome's most popular festivity.

Throughout the next millennium, our knowledge of Saturn didn't change much, and the planet was still considered to be a wandering star until the invention of the telescope. This new tool, invented in the early 17th century by a Dutch optician, quickly revolutionized astronomy.

Saturn Ring Tilt

Told about the new instrument, in 1609 the Italian scientist Galileo Galilei built his own homemade version of a telescope and pointed it at the heavens. Using what we would call today a meager telescope -- it had only magnified images by 20 times -- he noticed there was something special about the ringed planet. Galileo couldn't quite grasp what was "wrong" with the planet and he could only guess wrong answers.

At first he assumed Saturn was a group of three close-knit planets, with two smaller ones on each side of a bigger planet. Two years later, however, changes in Saturn's appearance baffled him. The two smaller planets had vanished and Saturn was now all by itself. Galileo wrote that he was "astonished" by this phenomenon. We know now that the rings seem to disappear as our view of the ring plane shifts. When they are seen at an edge-on angle, the rings are virtually invisible. A couple of years later, Galileo's observations became even more confusing when the rings reappeared, in their places next to Saturn.

"I do not know what to say in a case so surprising," he wrote in despair. He eventually suggested that Saturn must have had arms or "cup handles" that mysteriously grew and disappeared periodically. Galileo died without knowing that through his homemade telescope he was looking at Saturn's rings.

Christiaan Huygens		Giovanni Cassini

Confusion reigned until Christiaan Huygens, a Dutch astronomer, developed the concept of a planetary ring system in 1659. Using an improved telescope - one that could magnify images by 50 times -- Huygens theorized the rings to be solid, thin and flat. The new idea provided a model for astronomers of the day, who were then able to understand what they were seeing. As the quality of telescopes continued to improve, features became easier to identify. In 1676, Giovanni Cassini, an Italian astronomer who eventually became a French citizen, was able to see the biggest gap within the ring system, now known as the Cassini Division or the Cassini Gap. Cassini and Huygens also discovered moons around the ringed planet, and the known number of satellites orbiting Saturn has been growing ever since.