Saturn's Ghostly Outer Ring is Mind Blowingly Massive

By Maddie Stone on at

Almost every time we have a look, Saturn seems to become even more incredible. Space rain falls from icy rings into the gas giant’s atmosphere. Two of its moons, Titan and Enceladus, are among the best candidates in our solar system for finding alien life.

The latest revelation? Saturn’s faint, outermost ring is an absolute monster, spanning an area of space roughly seven thousand times larger than the gas giant itself.

“It’s fascinating that this ring can exist,” astronomer Douglas Hamilton, lead author of a new Nature paper detailing the prodigious ring told “We’re told in science that planetary rings are small and close to their parent planets — if they’re too far away from their planets, moons form rather than rings. This discovery just turns that idea on its head — the universe is a more interesting and surprising place than we thought.

First discovered by NASA’s infrared Spitzer Space Telescope in 2009, the ‘Phoebe ring,’ which gets its name from fine, dark dust particles siphoned off Saturn’s Phoebe moon, is a vast and elusive veneer. Originally, we thought the ring extended some 4.8 to 7.7 million miles from Saturn, making it well over 10 times larger than Saturn’s previously titanic E ring—which now looks rather shrimpy by comparison.

The Phoebe ring just got even bigger. In their new study, astronomers report the results of an infrared imaging analysis conducted using NASA’s Wide Field Infrared Explorer (WISE). According to the latest data, the Phoebe ring actually stretches from somewhere in the neighborhood of 3.75 to 10.1 million miles from Saturn. And these numbers may be revised upwards yet again, as our ability to detect heat signatures coming off the ring’s fine, dark grains improves.

Regardless, it’s clear at this point that Saturn is utterly swallowed by its rings, and every book, TV show and video game that’s ever depicted the glorious gas giant got it pretty darn wrong.

[ via Scientific American]

Read the full open-access article at Nature.

Top image: An artist’s depiction of Saturn’s outermost ring, via NASA / JPL / Space Sciences Institute