Galileo - Drawings of Saturn from 1610 and 1616

Galileo first saw Saturn through his telescope in 1610. He thought he was observing a planet with two moons, one on either side. His drawing from that date looks like a cup with two handles.

As he continued to observe the planet, during ensuing years, Galileo became mystified by what he saw. NASA tells us why:

Galileo Galilei was the first to observe Saturn with a telescope in 1610. Because of the crudeness of his telescope, he couldn't determine what the rings were. He incorrectly guessed that there were two large moons on either side of Saturn.

Two years later when he viewed Saturn again, the "moons" had disappeared. We know now this is because Galileo was viewing the rings edge-on so that they were invisible, but at the time it was very confusing to Galileo.

After another two years, Galileo viewed Saturn again and found that the "moons" had returned. He concluded that the rings were "arms" of some sort.