Saturn Archives

June 25, 2024June 25, 2024 by Mark Thompson

Saturn’s Energy is Out of Balance

Energy imbalance of Saturn (image credit: NASA/JPL)

Earth releases about as much energy out into space as it absorbs, arriving at a thermal equilibrium. This means it will reach an average temperature as is the case with most planets. Saturn however, is a little different as recent observations show the planet’s energy is out of balance. It seems that in addition to the energy it receives from the Sun, there must also be an internal source of heat, perhaps driven by its highly elliptical orbit.

February 13, 2024February 13, 2024 by Laurence Tognetti

Saturn’s “Death Star Moon” Mimas Probably has an Ocean Too

Saturn's moon, Mimas, captured by NASA's Cassini spacecraft in 2010. (Credit: NASA/JPL-Caltech/Space Science Institute)

A recent study published in Nature presents a groundbreaking discovery that Saturn’s moon, Mimas, commonly known as the “Death Star” moon due to its similarities with the iconic Star Wars space station, possesses an internal ocean underneath its rocky crust. This study was conducted by an international team of researchers and holds the potential to help planetary geologists better understand the conditions for a planetary body to possess an internal ocean, which could also possess the conditions for life as we know it. While Mimas was photographed on several occasions by NASA’s Cassini spacecraft, including a close flyby in February 2010, what was the motivation behind this recent study regarding finding an internal ocean on Mimas?

December 21, 2023December 21, 2023 by Nancy Atkinson

It’s Time for Saturn’s “Spokes” to Return

This NASA Hubble Space Telescope photo of Saturn reveals the planet's cloud bands and a phenomenon called ring spokes. NASA, ESA, STScI, Amy Simon (NASA-GSFC)

Astronomers have been observing Saturn with the Hubble Space Telescope and several other spacecraft for decades and have noticed something unusual. During seasonal changes, transient spoke-like features appear in the rings. These dark, ghostly blobs orbit around the planet 2-3 times, and then disappear.

As Saturn is approaching its equinox, this is prime spoke activity time. Once again, Hubble has been called to gaze at Saturn, tracking the behavior of the spokes and hopefully giving astronomers more clues as to why they occur.

November 21, 2023November 21, 2023 by Mark Thompson

In the Shadow of Saturn’s Rings

This image is a composite of observations made of Saturn in early 2018 in the optical and of the auroras on Saturn’s north pole region, made in 2017. Image from NASA/ESA Hubble Space Telescope — Composite image of Saturm from HST (Credit NASA/ESA)

I can remember it very well, although not actually sure when it was, back around 1995/1996 I think. I was, like most other keen stargazers very familiar with the sight of Saturn with rings and all. Indeed the view of Saturn with its rings was one of the first things I had ever seen through a telescope and it inspired me into a lifetime passion of exploring the night sky. Every 15 years though, the Earth passes through the plane of the rings and from Earth they seem to vanish. Now, an astronomer has used data taken during such ring plane crossings from the Cassini spacecraft to measure the transparency of the rings.

November 20, 2023November 21, 2023 by Laurence Tognetti

Saturn’s Rings will Disappear in 2025. Don’t Worry, They’ll Return Soon Enough

Image of ring-plane crossing at Saturn taken by NASA’s Hubble Space Telescope in May 1995, with a similar ring-plane crossing event scheduled to occur in March 2025. (Credit: Reta Beebe (New Mexico State University), D. Gilmore, L. Bergeron (STScI), NASA/ESA, Amanda S. Bosh (Lowell Observatory), Andrew S. Rivkin (Univ. of Arizona/LPL), the HST High Speed Photometer Instrument Team (R.C. Bless, PI), and NASA/ESA)

The rings of Saturn are some of the most well-known and captivating spectacles in the night sky, which are so large they can easily be observed with amateur telescopes or even a pair of high-powered binoculars. However, from time to time, Saturn’s rings “disappear” from view, a phenomenon known ring-plane crossing, with the rings being observed as a flat line running straight through the massive gas giant. Ring-plane crossing occurs approximately every 15 years and is slated to happen next in March 2025, with the rings slowly getting “larger” in the months afterwards before “disappearing” again in November 2025. But what causes ring-plane crossing?

September 28, 2023September 28, 2023 by Evan Gough

Colliding Moons Might Have Created Saturn’s Rings

Saturn's rings are arguably the most recognizable feature in our Solar System and are made mostly of ice particles. New research says a collision between icy moons may have created them in the recent past. Image Credit: NASA/JPL/Space Science Institute

If we could wind the clock back billions of years, we’d see our Solar System the way it used to be. Planetesimals and other rocky bodies were constantly colliding with each other, and new objects would coalesce out of the debris. Asteroids rained down on the planets and their moons. The gas giants were migrating and contributing to the chaos by destroying gravitational relationships and creating new ones. Even moons and moonlets would’ve been part of the cascade of collisions and impacts.

When nature crams enough objects into a small enough space, it breeds collisions. A new study says that’s what happened at Saturn and created the planet’s dramatic rings.

September 14, 2023September 14, 2023 by Nancy Atkinson

The Seasons on Saturn are Changing. It's Time to Say Goodbye to Its North Pole for a Few Years

Saturn, as seen by the James Webb Space Telescope's MIRI instrument, showing various portions of the planet's atmosphere. superimposed on an full image taken by the Hubble Space Telescope. Credit: NASA/ESA/Univ. Leicester/L.N. Fletcher/O. King

Just like Earth, Saturn goes through seasons because of its axial tilt. But a year on Saturn lasts 30 Earth years, so each of its seasons lasts 7.5 years. Right now, it is late summer on Saturn’s northern hemisphere, so again, just like Earth is currently heading for northern autumn equinox in September, Saturn is heading for northern autumn equinox a little later, in 2025.

Before Saturn’s north pole enters its extended polar winter – rendering it inaccessible for observations — astronomers are taking advantage of being able to study this area with the James Webb Space Telescope, which became operational just over a year ago.

August 14, 2023August 14, 2023 by Brian Koberlein

Storms on Saturn Can Have Impacts That Last for Hundreds of Years

A giant storm rages on Saturn. Credit: NASA/JPL-Caltech/SSI

The Great Red Spot of Jupiter is a storm that has raged for hundreds of years. It was first observed by Gian Domenico Cassini in 1665, and except for a period between 1713 to 1830, it has been observed continuously ever since. Even if Cassini’s storm is not the one we see today, the current red spot has been around for nearly two centuries. While great storms appear now and then on Saturn and other gas planets, they don’t have the staying power of Jupiter’s great storm. Or so we thought.

June 29, 2023July 1, 2023 by Evan Gough

Here Come JWST’s First Images of Saturn

Saturn by JWST — Image of Saturn and some of its moons, captured by the James Webb Space Telescope’s NIRCam instrument on June 25, 2023. Credits: NASA, ESA, CSA, STScI, M. Tiscareno (SETI Institute), M. Hedman (University of Idaho), M. El Moutamid (Cornell University), M. Showalter (SETI Institute), L. Fletcher (University of Leicester), H. Hammel (AURA); image processing by J. DePasquale (STScI)

Note: This story has been updated with new images.

It’s Saturn’s turn.

The JWST is aiming its powerful, gold-coated, segmented beryllium mirror at our Solar System’s second-largest, and perhaps most striking, planet. So far, we’ve only got a sneak preview of the raw images without any processing or scientific commentary.

But they’re a start.

May 30, 2023May 30, 2023 by Brian Koberlein

One Spacecraft Could Visit All of Saturn's Inner Large Moons

Saturn's largest moons. Credit: NASA / JPL-Caltech / Montage by Emily Lakdawalla / Processing by Processing by Ted Stryk, Gordan Ugarkovic, Emily Lakdawalla, and Jason Perry.

If you’ve ever played Kerbal Space Program, you know how difficult it can be to get your spacecraft into the orbit you want. It’s even more difficult in real life. This is why it’s pretty impressive to see a proposal to study all of Saturn’s large inner moons in one go.