Saturn

A light, windy giant

Saturn is the sixth planet from the Sun and the second largest after Jupiter. Like Jupiter, it is a gas giant made mostly of hydrogen and helium, with no solid surface.

Its average density is about 70 percent that of water. That makes Saturn the only planet less dense than water, so in a bathtub big enough it would float. The planet spins quickly too, and it is noticeably flattened: it is about 10 percent wider at the equator than from pole to pole.

Saturn's bands are softer and more muted than Jupiter's because a layer of haze sits above them. Underneath, winds near the equator can reach over 1,000 mph.

The rings

Saturn's main rings span about 175,000 miles from edge to edge, yet they are at most about 0.6 miles (1 km) thick, and much thinner in many places. Relative to their width, they are far thinner than a sheet of paper.

They are made of billions of pieces of water ice, mixed with a little rock and dust. The pieces range from grains smaller than sand to chunks as big as a house, each one orbiting Saturn like a tiny moon.

How old the rings are is still debated. Measurements from the Cassini spacecraft pointed to relatively young rings, perhaps a few hundred million years old, while other studies argue they could be as old as the planet.

Rings that disappear

Saturn is tilted by about 27 degrees, so as it travels around the Sun, we see its rings from changing angles. Twice in every 29.4-year orbit, Earth passes through the plane of the rings and we see them exactly edge-on.

This last happened on March 23, 2025, and the next crossing comes in 2038. Because the rings are so thin, they almost vanished from view in small telescopes for a while, leaving Saturn looking like a plain ball with a thin line through it.

Since then the rings have been slowly opening up again. Edge-on views come roughly every 13 to 15 years, with the rings opening to their widest tilt in between. So over about 15 years the rings go from closed to wide open and back again.

The hexagon

Around Saturn's north pole sits a six-sided cloud pattern about 20,000 miles across, more than twice the width of Earth. It is a jet stream, a fast band of wind, that runs in a near-perfect hexagon shape.

Voyager first spotted it in the early 1980s, and Cassini watched it change color from bluish to golden over several years as the seasons shifted. A large swirling storm sits at its center, right over the pole.

Scientists think the hexagon forms because winds of different speeds meet and create a stable wave pattern. Laboratory experiments with spinning fluids have produced similar many-sided shapes.

Titan and Enceladus

Saturn has 285 known moons as of 2026, more than any other planet. Most are small and irregular, but two stand out.

Titan, the largest, is bigger than Mercury and has a thick, hazy atmosphere made mostly of nitrogen. It is so cold that methane and ethane act like water does on Earth, falling as rain and filling rivers, lakes and seas. On January 14, 2005, ESA's Huygens probe parachuted to its surface, the most distant landing ever made.

NASA's Dragonfly mission plans to send a nuclear-powered drone to fly between sites on Titan. Its launch is planned for July 2028, with arrival at Titan in 2034.

Enceladus is only about 300 miles across, but it is one of the most exciting places in the Solar System. Jets near its south pole spray water vapor and ice grains into space from an ocean hidden under the ice, and Cassini flew through them and found salts, organic molecules and hydrogen, a hint of hot springs on the ocean floor.

Cassini and the Grand Finale

Pioneer 11 made the first flyby in 1979, followed by Voyager 1 and 2 in 1980 and 1981. The big leap came with Cassini, a joint NASA, ESA and Italian mission that launched in 1997, reached Saturn in July 2004 and carried the Huygens probe.

Cassini spent 13 years in orbit, studying the rings, the hexagon, Titan's lakes and Enceladus's plumes. As its fuel ran low, controllers sent it on 22 weekly orbits through the gap between the planet and its rings, a phase called the Grand Finale.

On September 15, 2017, Cassini plunged into Saturn's atmosphere on purpose. This kept it from ever crashing into, and possibly contaminating, moons that might be habitable.

How to see Saturn

To the naked eye, Saturn looks like a steady, pale yellow star. It is not as bright as Jupiter, but it is easy to find once you know where to look, and it is best placed around opposition, which comes about every 54 weeks.

Binoculars show that Saturn looks slightly oval but usually cannot reveal the rings clearly. A small telescope at about 25x or more shows the rings as a separate shape around the planet, a view that surprises many first-time observers.

With more magnification you may spot Titan as a nearby point of light, the shadow of the planet on the rings, and on good nights the dark Cassini Division between the two brightest rings. Because the rings are still close to edge-on after 2025, they will look narrow for the next few years and widen gradually toward their next maximum tilt.