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Mysterious 'Spokes' in Saturn's Rings are Still There

There are many mysteries about the enigmatic ringed gas giant, but the curious mechanism behind Saturn's 'spokes' is one of the more intriguing puzzles. Continue reading →

There are many mysteries about the enigmatic ringed gas giant, but the curious mechanism behind Saturn's ‘spokes' is one of the more intriguing puzzles. And in new observations from NASA's Cassini mission, these bright features seem to be persisting in Saturn's darkened B ring.

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Observed first during the Voyager spacecraft flybys in the early 1980′s, it was realized that these strange features, which flare out like spokes on a bicycle wheel, were not caused by gravitational interactions with the planet, moons or ring material. Further observations were made by Cassini in 2005 when it was confirmed the spokes are likely related to the gas giant's global magnetic field.

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The leading theory is that charged dust particles suspended above and below the rings are interacting with Saturn's magnetic field, causing the spokes to rotate with the planet's interior spin. They are also thought to be seasonal over Saturn's near-30 year solar orbit - they vanish during Saturn's midwinter and midwinter, only to reappear around the Saturnian equinox. As Saturn's northern hemisphere approaches summer solstice, astronomers predict the spokes will disappear.

This observation was taken when Cassini was zooming approximately 1.2 million miles (1.9 million kilometers) above Saturn's ring plane in October 2013.

For more information about this image, browse the Cassini mission site.

The bright spokes in Saturn's darkest B ring appear as bright features that rotate with the planet's magnetic field.

This Christmas season,

NASA's Cassini mission got into the festive spirit

, capturing some breathtaking views of the beautiful ringed gas giant Saturn. Along with Saturn and its majestic rings, views of the Saturnian moons Titan, Enceladus and Rhea were also shared, showcasing some of the system's most fascinating mysteries such as Titan's south polar vortex, ring resonances and Saturn's hexagonal northern jet stream. Shown here, in a wide angle shot of Saturn's north pole, the hexagon is clearly visible.

As winter approaches the southern hemisphere of Saturn, a familiar blue hue returns to the gas giant's clouds.

In this view of Saturn's rings, the "Titan Ringlet," embedded within the Colombo Gap in the center of this Cassini photo, can be seen. The Ringlet is slightly oval shaped with its axis always pointing toward Titan. This is one example of the gravitational moon-ring resonances that shape Saturn's rings.

The moons Titan and Rhea line up from Cannini's perspective. Titan is Saturn's biggest moon that plays host to a thick, hazy atmosphere. Crater-riddled Rhea, the second largest, is barren in comparison.

The stacked clouds over Titan's south polar vortex are lit up by the twilight sun.

Titan's hydrocarbon lakes become visible through the moon's atmosphere as Cassini uses a special filter to cut through the haze.

A beautiful ring is created as Cassini observes Titan's dark side, the moon's thick atmosphere scattering sunlight.

A half crescent Enceladus, Saturn's icy moon.