Saturn’s Ghostly Outer Ring Is Much, Much Bigger Than We Thought

saturn phoebe ring

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.

“We knew that the ring was big, but we now know exactly how big it is!” Dr. Douglas P. Hamilton, an astronomy professor at the University of Maryland in College Park and the study’s lead author, told The Huffington Post in an email.

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This artist’s conception simulates an infrared view of the giant Phoebe ring.

A second look. Back when they first observed the ring, Hamilton and his colleagues could see only a small cross section of it based on data collected by the Spitzer Space Telescope. For the new study, they analyzed images taken by NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft, which showed the ring in its entirety.

They found that the ring starts at a distance around 100 “Saturn radii,” or around 3.7 million miles, from the planet’s body. And it extends as far as 275 Saturn radii, which is about 10 million miles.

In other words, if you picture Saturn as the size of a basketball, the ring extends around two thirds of the length of a football field away from it, Science reported.

Sifting the dust. The 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 —> Read More