The NASA's Spitzer Space Telescope has discovered a gigantic unknown ring around Saturn that extends at least 24 million kilometers in diameter which is 200 times the diameter of Saturn. The news was announced by a team of researchers at the annual meeting of the American Astronomical Society’s Division for Planetary Sciences. The newly found ring is comprised of a very thin layer of ice and dust that it cannot be seen in the visible light spectrum, but instead was discovered in the infrared spectrum as a "glow" by Spitzer's IR detector. The ring appears to share the same orbital plane and direction as the Saturnian moon Phoebe which is opposite the direction of all other Saturnian moons. The ring would also explain the mysterious phenomenon of the ying yang moon Iapetus which has one side with a lighter surface and the other side covered with a much darker material.
The picture above is the artist rendering of what the new Saturn ring should look like. A publication of the findings is posted online in the science journal Nature by Anne Verbiscer and Michael Skrutskie of the University of Virginia in Charlottesville, along with Douglas Hamilton of the University of Maryland in College Park.
This is photo of Iapetus taken be the Cassini spacecraft in Sept 2007. The new ring resolves the mystery surrounding the accumulation of dark material on one side of the moon.
For more articles about the new ring here are some links:
Largest known planetary ring discovered Science News
Largest ring in solar system found around Saturn New Scientist
New ring detected around Saturn BBC