Written by Matt Lastovka
Here, in the third installation of our Planet Series, I will discuss Saturn. Known for its stunning beauty and dazzling rings, Saturn is perhaps the most recognizable object in our Solar System. I hope I can convince you that Saturn is the most interesting planet in our solar system.
It is the farthest planet from Earth that can be seen with the naked eye, and thus the earliest recorded observation of Saturn date to about 700 BCE from ancient Assyria. The Greeks named it after Kronos, the god of agriculture and father of Zeus around 400 BCE. The Romans later changed the name to Saturn when they rebranded the ancient Greek gods. Most ancient astronomers, however, could not see Saturn’s rings, with the possible exception of New Zealand’s Maori, whose name for Saturn translates roughly to “surrounded by a headband.” Even when Galileo first trained his telescope on Saturn, he did not recognize the rings. He thought Saturn was some kind of triple-planet system. It wasn’t until 1655 that Christiaan Huygens first described and sketched Saturn’s rings.
Saturn’s internal structure is similar to Jupiter’s. It contains a dense, rocky core surrounded by a large atmosphere of hydrogen and helium. Interestingly, Saturn is the only planet in our Solar System whose average density is less than water, meaning Saturn would float in a sufficiently large bathtub. Saturn’s atmosphere is characterized by intense winds, which can reach up to 500 meters per second (about 4.5 times faster than the strongest hurricanes on Earth). Saturn also has a massive, hexagon-shaped storm at its North Pole measuring 20,000 miles across.
Saturn’s rings are made of small ice and dust particles, most ranging in size from tiny grains to chunks as big as a house. They are incredibly thin, only measuring about 300 feet in height. That might seem like a lot, but if you blew up a sheet of paper to the size of Saturn’s rings, it would be a thousand times thicker than Saturn’s rings. They may have been formed by when the planet’s strong gravity shredded one or more of its moons about 100 million years ago, making Saturn’s rings a very new phenomenon in our Solar System. Some astronomers also suggest that they will disappear in about 50 million years when they are swallowed into Saturn itself.
Arguably the most interesting parts of Saturn are its moons. Saturn has at least 83 different moons, ranging in size from a few hundred miles in size to larger than Mercury. Mimas is known for having a large crater making it look suspiciously like the Death Star. Phoebe is located within the rings and carved out an empty band within the ring structure. The largest moon, Titan, has a thick atmosphere, and liquid lakes and rivers on its surface. However, Titan is too cold for water to be a liquid; instead, it has liquid methane on its surface, and it even rains methane. Enceladus is believed to have subsurface water oceans and features jets similar to geysers that were found to have organic molecules in them. These jets may be powered by hydrothermal vents in the oceans, which are significant because those are the places life is believed to have started on Earth. The presenc of the building blocks of life in such a place makes Enceladus a potential home for microbial life.