An analysis of the latest infrared images of Saturn's supersized ring revealed that it is even larger than previously thought. This latest discovery—published in the June 11 issue of the journal Nature— is expected to change the belief that planetary rings are small and are close to their parent planets.
Saturn's supersized ring was discovered in 2009 by NASA's Spitzer Space Telescope. It is so wide that it can fit two full moons and would take one billion Earths to fill it. It's mainly composed of ice and dust, which could have originated from Phoebe, one of Saturn's farthest moons that circles within the ring.
So it was known that Saturn has this supersized ring, but researchers at the University of Maryland, College Park, found that it is actually even larger than previously thought. Spitzer's initial measurement of the ring suggested that it extends up to 12.4 million kilometers away from the planet. But when NASA's WISE spacecraft released the ring's latest infrared images, it revealed that it actually reaches up to 16.2 million kilometers away from Saturn, making it 3.8 million kilometers larger.
"We knew it was the biggest ring, but now we find it's even bigger than we thought, new and improved," said Douglas Hamilton, study lead author and a planetary scientist at the University of Maryland, College Park, to Space.com.
The ring is so large that it is now an outlier on planetary science.
"It's fascinating that this ring can exist," said Hamilton. "We're told in science textbooks 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."
Another observation noted by the scientists is that Saturn has three kinds of rings that reform every hour. The team plans to look at Jupiter to determine if its ring has the same behavior as Saturn's supersized ring.
