This week marks the anniversary of when the rings of Saturn were observed for the first time!
On July 30, 1610 in Padua, Italy, astronomer Galileo Galilei made this incredible observation. The problem was, Galilei didn’t know they were rings! The telescope was still an early invention at the time, and not yet powerful enough to see the rings clearly. Instead, Galilei thought Saturn might have handles or a large moon on each side.
In a letter, he wrote: “Saturn is not a single star, but is a composite of three, which almost touch each other, never change or move relative to each other, and are arranged in a row along the zodiac, the middle one being three times larger than the lateral ones.”
Two years later, Galileo Galilei the strange objects were gone! Now, we understand that he was viewing Saturn when its rings were edge-on and virtually invisible (Saturn is tilted at almost the same angle as Earth, but has a 30-year orbit so we observe Saturn at different angles over time). Two more years went by, and the objects were back!
In 1659, Dutch astronomer Christiaan Huygens determined the mysterious shape of Saturn was actually a ring, which he believed was a solid disk. Fast-forward to 1675 when Gian Domenico Cassini (yes, the Cassini spacecraft is named after him!) observed a gap in the rings, leading to the eventual understanding that the rings of Saturn are made of millions of tiny pieces of ice.
Interested in more space stories like this one? Stop by our all-live show, “Wonders of the Night Sky,” playing every day in the Jennifer Chalsty Planetarium, the biggest planetarium in the Western Hemisphere. A portion is always set aside for LSC Space News Now stories.