In 1610, Galileo was the first to observe Saturn through a telescope, and was puzzled by its "lobes" or "handles." He suggested two moons flanked the planet. Christiaan Huygens was the first to propose that Saturn had a ring; his 1659 illustration shows how the ringed planet would look in orbit around the Sun. Credit: Linda Hall Library
Christiaan Huygens was a Dutch astronomer — as well as a physicist, inventor, mathematician, engineer, and more.
As far as his astronomical achievements, he ground lenses for refracting telescopes, invented a better eyepiece (one with two lenses) than those available at the time, and was the first to correctly identify the nature of Saturn’s rings. He also discovered Saturn’s largest moon, Titan, and, by spotting Syrtis Major on Mars, became the first person to observe a surface feature on another planet. More tangentially related to astronomy, he also developed the theory that light is a wave and invented the pendulum clock.
