[meteorite-list] Cassini Spacecraft Sees New Objects Blazing Trails in Saturn Ring

[Ron Baalke]

April 23, 2012

Dwayne Brown 
Headquarters, Washington 
202-358-1726 
dwayne.c.brown at nasa.gov 

Jia-Rui C. Cook 
Jet Propulsion Laboratory, Pasadena, Calif. 
818-354-0850 
jccook at jpl.nasa.gov 

RELEASE: 12-128

CASSINI SPACECRAFT SEES NEW OBJECTS BLAZING TRAILS IN SATURN RING

WASHINGTON -- Scientists working with images from NASA's Cassini 
spacecraft have discovered strange, half-mile-sized objects punching 
through one of Saturn's rings and leaving glittering trails behind 
them. The results will be presented tomorrow at the European 
Geosciences Union meeting in Vienna, Austria. 

The penetration occurred in the outermost of Saturn's main rings, 
called the F ring, which has a circumference of 550,000 miles 
(881,000 kilometers). Scientists are calling the trails in the F ring 
"mini-jets." Cassini scientists combed through 20,000 images and 
found 500 examples of these rogues during the seven years Cassini has 
been at Saturn. 

"Beyond just showing us the strange beauty of the F ring, Cassini's 
studies of this ring help us understand the activity that occurs when 
solar systems evolve out of dusty disks that are similar to, but 
obviously much grander than, the disk we see around Saturn," said 
Linda Spilker, Cassini project scientist at NASA's Jet Propulsion 
Laboratory (JPL) in Pasadena, Calif. 

Scientists have known relatively large objects can create channels, 
ripples and snowballs, or clumps of icy material, in the F ring. 
However, scientists did not know what happened to these snowballs 
after they were created. Some were broken up by collisions or tidal 
forces in their orbit around Saturn. Scientists now have evidence 
some of the smaller ones survived, and their differing orbits mean 
they go on to strike through the F ring on their own. 

"I think the F ring is Saturn's weirdest ring, and these latest 
Cassini results go to show how the F ring is even more dynamic than 
we ever thought," said Carl Murray, a Cassini imaging team member 
based at Queen Mary University of London, U.K. "These findings show 
us that the F ring region is like a bustling zoo of objects from a 
half-mile (0.8-kilometer) in size to moons like Prometheus a hundred 
miles (160.9 kilometers) in size, creating a spectacular show." 

These small objects appear to collide with the F ring at gentle speeds 
about 4 mph (2 meters per second). The collisions drag glittering ice 
particles out of the F ring with them, leaving a trail of 20-110 
miles (40-180 kilometers) long. 

In some cases, the objects traveled in packs, creating mini-jets that 
looked exotic, like the barb of a harpoon. Other new images show 
grand views of the entire F ring and the swirls and eddies from the 
different kinds of objects moving through and around it. 

Saturn's rings are comprised primarily of water ice. The chunks of ice 
that make up the main rings spread out 85,000 miles (140,000 
kilometers) from the center of Saturn. Scientists believe the rings' 
average thickness is approximately 30 feet (10 meters). 

The Cassini-Huygens mission is a cooperative project of NASA, the 
European Space Agency and the Italian Space Agency. JPL manages the 
mission for NASA's Science Mission Directorate in Washington. The 
imaging team is based at the Space Science Institute in Boulder, 
Colo. 

New images and movies of the mini-jets are available at: 

http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20120423.html 

For information about Cassini, visit: 

http://www.nasa.gov/cassini 
	
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