Saturn's Ghostly Outer Ring Is Much, Much Bigger Than We Thought
Astronomers were stunned in 2009 when they discovered a gargantuan, never-before-seen eighth ring around Saturn. The "Phoebe ring," as it was dubbed, lies far outside the planet's seven main ring groups and is made of dark particles that make it hard to spot except in infrared light.
Now a new study reveals the ring is even more impressive -- about 30 percent bigger -- than previously thought. It covers an area of the sky that's 7,000 times larger than Saturn itself.
he ring is composed mostly of dust particles no bigger than the width of a human hair. Rocks that are soccer-ball-sized or larger, at least 20 centimeters in diameter, make up no more than 10 percent of the ring -- which is unusual compared to other rings in the solar system.
Where does the dust come from? Previously, scientists believed that it streams off of Saturn's moon Phoebe as the satellite gets pelted by comets. Now scientists believe some of it may come from other "hidden" moons that are too small for our telescopes to see, according to NPR.