Saturn has been known since prehistoric times because it is visible to the naked eye. The first recorded telescopic observation of Saturn was made by Italian astronomer Galileo Galilei in 1610. However, due to the limited quality of his telescope, Galileo could not identify Saturn's rings and mistakenly thought the planet had two large moons on either side

. The true nature of Saturn's rings was first correctly described by Dutch astronomer Christiaan Huygens in 1655. Using a more powerful telescope, Huygens deduced that Saturn was surrounded by a thin, flat ring that did not touch the planet itself. He also discovered Saturn's largest moon, Titan

. Later, in 1675, Italian-French astronomer Giovanni Domenico Cassini discovered four additional moons of Saturn and identified the gap in the rings now known as the Cassini Division

Summary:

• Saturn known since ancient times (visible to naked eye)
• First telescopic observation: Galileo Galilei, 1610 (rings not understood)
• First accurate description of rings: Christiaan Huygens, 1655
• Discovery of additional moons and ring gap: Giovanni Domenico Cassini, 1675

Thus, while Galileo was the first to observe Saturn through a telescope, Christiaan Huygens was the first to discover and accurately describe Saturn's rings. Cassini contributed further discoveries about the moons and ring structure