See the James Webb Telescope’s First Image of Saturn and Its Rings

The James Webb Space Telescope has captured its stunning, first official image of Saturn and its rings. With this new view of the iconic planet, the telescope has now taken images of all four of the solar system’s gas giants.

In the new picture from the telescope’s Near-Infrared Camera (NIRCam), four of Saturn’s rings shine brightly, with the planet itself appearing dimmer. Three of its moons can be seen as pinpricks of light on the left side.

Webb’s capture of Saturn appears starkly different from past images of the planet—gone are the gas giant’s recognizable bands, and in their place is a darker-looking orb encircled by the rings.

“It’s not a familiar view of Saturn by any stretch of the imagination,” Leigh Fletcher, a planetary scientist at the University of Leicester in England, tells New Scientist’s Alex Wilkins.

That’s because, at the infrared wavelengths observed by NIRCam, methane gas absorbs most of the sunlight hitting the planet’s atmosphere, according to a NASA blog post. While this effect makes the planet look dark, its icy rings appear to shine, reflecting plenty of light that the telescope can detect.

Visible in the image are Saturn’s A, B, C and F rings. The planet has seven rings in total, named alphabetically in the order they were discovered. Each ring comprises chunks of rock and ice from bodies like comets and asteroids, broken apart by the planet’s gravity. Some pieces are smaller than a grain of sand, while others are the size of a house. A few even rival Earth’s mountains in size.

Between the A and B rings lies the Cassini division, a 2,920-mile gap shown in the NIRCam image. The Encke gap in Saturn’s A ring, also seen in the image, is where the moon Pan resides. Research published earlier this year suggests that Saturn’s rings are much younger than the planet itself.

The moons seen to the left of Saturn are Dione, Tethys and Enceladus. Astronomers think Enceladus is a strong candidate for supporting life: After research published last month detected phosphorus in data collected by the Cassini spacecraft, scientists have now found all six elements essential to life as we know it in material from Enceladus’ ocean. In a recent, important discovery, Webb spotted a giant plume of water vapor spewing 6,000 miles out from Enceladus’ ocean and feeding Saturn’s E ring.

we finally have JWST images of all of the gas giants!!! pic.twitter.com/nr2uUN8QTm

— Jasmine (@astro_jaz) June 30, 2023

Webb’s new photo is part of a series of deeply exposed images that scientists hope will reveal more about Saturn, including insights into its fainter G and E rings.

“We look forward to digging into the deep exposures to see what discoveries may await,” Matthew Tiscareno, a senior research scientist at the SETI Institute who led the process of designing the telescope’s observation of Saturn, says in a statement.

Additionally, researchers hope Webb can spot more moons around the gas giant, per NASA’s blog post. Saturn has the most known moons in the solar system by far—the discovery of 62 moons earlier this year brought its total to 145, clinching the planet’s spot at the top of the solar system’s “moon race.” Jupiter, the runner up, has 95 known moons.

From its orbit around the second LaGrange point, a spot roughly one million miles from Earth in the direction opposite the sun, Webb can’t observe the planets interior to its orbit. So, with Earth, Venus and Mercury off-limits for that reason, Saturn represents the last of the telescope’s planetary targets in our solar system to be imaged with NIRCam. The telescope gazed at Jupiter last summer and subsequently captured images showcasing Neptune’s rings and moons, Mars’ cratered surface and Uranus’ rings.

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.