With its resplendent ring system, Saturn is arguably the most stunning planet in our solar system. Located sixth in line from the sun, it is the second-largest world orbiting the sun, after Jupiter.
Though Saturn is famous for its rings, all the other giant planets, including Jupiter, Uranus and Neptune, feature ring systems. But Saturn stands out for having beautiful yellow and gold bands across its surface, as well as having more moons than any other planet in the solar system, some of which are among the best places to search for life outside Earth.
Saturn was known as Kronos in Greek and Sani in Sanskrit, according to the educational website The Nine Planets. Other ancient names for the planet include Sao (Thai), Zuhal (Arabic), Kayvon (Farsi), Tuxing (meaning Star of Soil in Mandarin), and Kayamanu (Babylonian), according to TKTKTKT.
The planet has a dense core made of metals such as iron and nickel, surrounded by rocky material that is in turn enveloped by liquid metallic hydrogen subject to intense temperatures and pressures. Recent research has suggested that Saturn’s core isn’t a solid sphere like the Earth’s, but rather a fuzzy soup composed of rocks, ice and metallic fluids sloshing around and affecting its gravitational pull, which in turn influences the structure of its gigantic rings.
Saturn’s outermost layers are made from swirling gases of mostly hydrogen and helium, plus trace amounts of water, ammonia and methane, that become liquid as pressures and temperatures increase deeper down, according to NASA. It is the least dense planet in the solar system, with an average density less than that of water, meaning it would float in a (very large) bathtub.
Winds in the upper atmosphere of Saturn are far stronger than those produced by hurricanes on Earth, reaching an astounding 1,090 mph (1,755 km/h in its equatorial regions. The planet’s clouds come in different shades of brown, yellow and gray, and they form a mysterious and strange hexagonal-shaped storm system at the north pole.
Bolts of lightning thought to be 10,000 times more powerful than those on Earth can be seen on Saturn, and NASA’s Cassini spacecraft spotted a storm that affected the planet’s weather patterns for more than three years, according to ESA. Because of its fast rotation rate, Saturn is visibly flattened at its poles, according to the agency.
The planet has the second-shortest day in the solar system, at only 10.7 hours, just slightly longer than Jupiter’s 9.93-hour day. Saturn has an axial tilt very close to our own, about 26.73 degrees with respect to its orbit around the sun (Earth's is 23.5 degrees), meaning that Saturn experiences seasons similar to our own planet.
NASA’s Voyager 1 flew past Saturn in 1980 and, along with Voyager 2, which reached the planet in 1981, snapped nearly 16,000 images of Saturn, its rings and moons. The two probes discovered three new moons, studied the intricate ring system in detail, and collected data about the planet’s magnetic field and atmosphere. After encountering the largest moon, Titan, Voyager 2 was directed up and out of the plane of the ecliptic, which is the plane in which all of the planets orbit around the sun, giving researchers an overhead view of the planet and its rings.
The most in-depth study of Saturn was done by the NASA-ESA joint Cassini-Huygens mission, which launched from Earth in 1997 and reached the ringed gas giant in 2004, according to ESA. The Huygens probe landed on Titan in 2005, becoming the first robot to reach the surface of a moon in the outer solar system. It took amazing photos of seas, river channels and mountains as it descended. Cassini remained in orbit around Saturn until Sept. 15, 2017, making a total of 294 orbits and then plunging into the planet’s atmosphere, according to the Planetary Society.
Titan is an incredible world wrapped in a dense atmosphere of nitrogen and hydrocarbons. This sludge forms a yellowish haze sitting at a frigid minus 290 degrees Fahrenheit (minus 180 degrees Celsius), below which can be found incredible geological features such as lakes, seas and rivers of liquid methane and ethane.
The largest sea on Titan is called Kraken Mare and is more than 1,000 feet (300 meters) deep, roughly the same height as New York City's Chrysler Building. Kraken Mare is so deep that Cassini’s radar was unable to probe all the way to the bottom. The moon’s seas appear to be preternaturally calm, with waves just 0.25 inches (1 centimeter) high by about 8 inches (20 cm) long.
With its thick atmosphere and bodies of liquid on the surface, Titan is one of the places in the solar system thought to potentially host life, according to NASA. A further sea of liquid water might sit below its icy crust, and the agency has planned the Dragonfly mission to launch in 2026 and explore the moon in more detail, according to the Planetary Society.
Another of Saturn’s most intriguing moons is Enceladus. It is surrounded by a frozen ice shell from which shoot tall geysers of liquid water at 800 mph(1,290 km/h), according to NASA. Though Enceladus is tiny — a mere 313 miles (504 km) across — Cassini has spotted methane coming from fractures known as tiger stripes near its south pole, a possible hint of organisms living in its subsurface ocean.
Some astrobiologists think Enceladus’ ocean has been around for just long enough, roughly 1 billion years, for chemicals to get dissolved and kickstart the processes that fuel life. But whether there is anything swimming around below its frigid crust remains to be seen.
Saturn’s other moons hold surprises. For instance, Mimas, a little world with a big crater that makes it looks kind of like the Death Star from the Star Wars series might also have a body of liquid water trapped beneath its outer ice.
Saturn's rings extend up to 175,000 miles (282,000 km) from the planet, yet are razor thin, with a vertical height averaging only 30 feet (10 m) in the main rings, according to NASA. The rings are named for the order in which they were discovered, with the main rings being the A, B, and C rings, while the D, E, F, and G rings are fainter and more recently discovered. There is a gap measuring 2,920 miles (4,700 km) between the A and B rings.
Very far out, there is the very faint ring in the orbit of Saturn's moon Phoebe. Material is constantly falling from the rings toward Saturn in a phenomenon known as "ring rain," meaning the stunning ring system is likely to be depleted in as little as 100 million years.