Cassini spacecraft provides compelling evidence for patterns resembling spokes on a pinwheel in Saturn's outer ring

http://www.news.cornell.edu/stories/Nov05/Nicholson.Cassini.lg.html

Nov. 9, 2005

By Lauren Gold
lg34@cornell.edu

By watching a distant star as it passed behind Saturn's outer rings, Cornell University astronomers on NASA's Cassini-Huygens mission to Saturn have found the most direct evidence to date of patterns, called gravitational wakes, within the planet's outer rings.

The patterns, thin, parallel striations like spokes on a pinwheel, have been theorized since the 1970s, but their small scale (just 100 meters -- 328 feet -- wide) makes them impossible to see even with the spacecraft's high-resolution camera. The new evidence of their existence, says Phil Nicholson, Cornell professor of astronomy, gives scientists clues about how thick Saturn's rings are and how their constituent bodies interact.

Nicholson presented his findings in September at the American Astronomical Society's 37th Division for Planetary Sciences meeting in Cambridge, England.