Saturn's Outer Ring Holds More Surprises
It's way bigger than previously thought, but made up of small particles
By John Johnson,  Newser Staff
Posted Jun 11, 2015 2:29 PM CDT
This artist's rendering released by NASA in 2009 shows the biggest but never-before-seen ring around Saturn, spotted by NASA's Spitzer Space Telescope.   (AP Photo/Artist's Rendering courtesy NASA's Jet Propulsion Laboratory)

(Newser) – About six years ago, scientists discovered a huge ring around Saturn that also happened to be invisible to the naked eye. Now, they've learned that it's much bigger than they thought, and their theory on how it came to be might change some thinking about planetary rings and moons. Scientists previously estimated the ring to be about 200 times the radius of Saturn, but now they say it's 30% larger, or about 270 times the radius, they write in Nature. It stretches more than 10 million miles, which a post at Phys.org puts into perspective: "If Saturn were merely the size of a basketball, this new outer ring would extend nearly two thirds the length of a football field away from it." Or as lead author Douglas Hamilton puts it in the Los Angeles Times: “It is 10 to 20 times larger than the second-biggest ring, so this thing is absolutely gargantuan.”

Researchers also found that the ring is made of up surprisingly small particles, with only about 10% of them larger than a soccer ball. They suspect the material, which is quite spread out within the ring, comes from the Saturn moon Phoebe, but it was previously believed that debris ejected at such a distance would form a moon rather than a ring. "Now it appears such theories will have to be rethought," says the Phys.org post. The ring can be detected only in infrared wavelengths. Based on all this, it's possible that Jupiter, Uranus, and Neptune have similar rings, reports Wired. “Maybe ring isn’t even the right word anymore," says Hamilton, "Maybe we should call them clouds. Those are much harder to detect and convince yourself that they’re real.” (Another of Saturn's moons might be able to support life.)