A new ring was discovered around Saturn last October with the help of the Spitzer Telescope. This new ring, called Phoebe's Ring, is the largest planetary ring now known. Phoebe's Ring begins about 6 Gigameters (3.7 million miles) away from the planet, and extends another 12Gm (7.4 million miles). This makes the ring nearly 35 times larger than the previously known ring system, and 300 times wider than Saturn!
Fun Fact: If Phoebe's Ring were visible in the night sky, it would appear twice as wide as the moon!
Sources:
www.planetary.org/blog/article/00002165/
www.windows.ucar.edu/tour/link=/saturn/saturn_phoebe_ring.html
www.nasa.gov/mission_pages/spitzer/news/spitzer-20091006.html#
All pictures courtesy of NASA