Hi My Friends: A VUELO DE UN QUINDE EL BLOG., Scientists working with images from NASA's Cassini spacecraft have discovered strange half-mile-sized (kilometer-sized) objects punching through parts of Saturn's F ring, leaving glittering trails behind them. These trails in the rings, which scientists are calling "mini-jets," fill in a missing link in our story of the curious behavior of the F ring. The results will be presented tomorrow at the European Geosciences Union meeting in Vienna, Austria.
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Download Image› Full Size› 1600 x 1200 › 1024 x 768 › 800 x 600 Wavy, Wiggly Ring
The constant change in Saturn's wavy, wiggly F ring is on display in this set of images obtained by NASA's Cassini spacecraft. The images show a view looking directly down onto the ring with the planet removed from the center. The radial distance from the center of the F ring has been exaggerated by a factor of 140 to make the wiggles and other radial structures more visible.
The regular patterns here primarily occur because of the gravitational pull of the moon Prometheus, which averages about 53 miles or 86 kilometers in diameter. Prometheus can create channels and snowballs as they part and push together icy F ring particles. These regular wiggles are about 65 miles (100 kilometers) from top to bottom. Other processes are also at work. In the top left image, the object known as S/2004 S 6 – which may be a moonlet or just a dense clump – has produced an extended trail of material that can be seen at the top left of the image. A close-up of this event can be seen in PIA08863. In some of the images (bottom row, middle and right image), a bright spiral ring is visible. This was caused by an object, possibly S/2004 S 6, colliding with the main F ring and producing a trail of particles that subsequently sheared right around the planet. These events give the F ring its multi-stranded appearance. Cassini's narrow-angle camera obtained the images in the top row on Dec. 23, 2006; Feb. 27, 2007 and Mar. 17, 2007 (left to right). In the bottom row, the images were obtained on April 18, 2007; Jan. 7, 2008 and Feb. 24, 2008. The F ring is the outermost of Saturn's main rings, with a radius of about 87,129 miles (140,220 kilometers). The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, DC. The Cassini orbiter was designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov . Image credit: NASA/JPL-Caltech/SSI/QMUL |
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This set of six images obtained by NASA's Cassini spacecraft shows trails that were dragged out from Saturn's F ring by objects about a half mile (1 kilometer) in diameter. Scientists have seen more than 500 of these kinds of trails in over 20,000 images collected by Cassini from 2004 to 2011. The trails seen in this set are typical of the entire collection. From left to right in the top row, the trails in these images are 18, 85 and 96 miles long (29, 136 and 155 kilometers long). In the bottom row from left to right, the trails are 43, 129 and 32 miles long (69, 207 and 51 kilometers long).
The trails are also called "mini-jets" by Cassini scientists. Scientists believe they were originally formed by the pull of the moon Prometheus, which averages about 53 miles or 86 kilometers across, on tiny F ring particles.
As Prometheus works its way around Saturn, its gravitational attraction sometimes parts channels in the icy particles of Saturn's F ring and sometimes pushes together sticky snowballs. The moon's continued progress around Saturn pulls some of the snowballs apart over time and adds material to others. These trails appear to be the telltale signs of surviving, evolved snowballs that strike through the F ring on their own. Scientists have been able to use Cassini images to track the objects and be sure they have different orbits from the F ring. The collisions occur at gentle speeds, on the order of 4 mph (2 meters per second). The F ring is the outermost of Saturn's main rings, with a radius of about 87,129 miles (140,220 kilometers).
More unusual examples of these trails can be seen in PIA15504. Other examples of these trails can be seen in PIA15500 and PIA15501.
The images were obtained by Cassini's narrow-angle imaging camera. From left to right along the top row, the images were taken on Aug. 2, 2005; Nov. 12, 2006 and Jan. 7, 2008. Along the bottom row, the images were taken on Jan. 7, 2008; May 10, 2008 and Aug. 20, 2008.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission
The trails are also called "mini-jets" by Cassini scientists. Scientists believe they were originally formed by the pull of the moon Prometheus, which averages about 53 miles or 86 kilometers across, on tiny F ring particles.
As Prometheus works its way around Saturn, its gravitational attraction sometimes parts channels in the icy particles of Saturn's F ring and sometimes pushes together sticky snowballs. The moon's continued progress around Saturn pulls some of the snowballs apart over time and adds material to others. These trails appear to be the telltale signs of surviving, evolved snowballs that strike through the F ring on their own. Scientists have been able to use Cassini images to track the objects and be sure they have different orbits from the F ring. The collisions occur at gentle speeds, on the order of 4 mph (2 meters per second). The F ring is the outermost of Saturn's main rings, with a radius of about 87,129 miles (140,220 kilometers).
More unusual examples of these trails can be seen in PIA15504. Other examples of these trails can be seen in PIA15500 and PIA15501.
The images were obtained by Cassini's narrow-angle imaging camera. From left to right along the top row, the images were taken on Aug. 2, 2005; Nov. 12, 2006 and Jan. 7, 2008. Along the bottom row, the images were taken on Jan. 7, 2008; May 10, 2008 and Aug. 20, 2008.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission
PASADENA, Calif. – Scientists working with images from NASA's Cassini spacecraft have discovered strange half-mile-sized (kilometer-sized) objects punching through parts of Saturn's F ring, leaving glittering trails behind them. These trails in the rings, which scientists are calling "mini-jets," fill in a missing link in our story of the curious behavior of the F ring. The results will be presented tomorrow at the European Geosciences Union meeting in Vienna, Austria.
"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, England. "These findings show us that the F ring region is like a bustling zoo of objects from a half mile [kilometer] in size to moons like Prometheus a hundred miles [kilometers] in size, creating a spectacular show."
Scientists have known that relatively large objects like Prometheus (as long as 92 miles, or 148 kilometers, across) can create channels, ripples and snowballs in the F ring. But scientists didn't know what happened to these snowballs after they were created, Murray said. Some were surely broken up by collisions or tidal forces in their orbit around Saturn, but now scientists have evidence that some of the smaller ones survive, and their differing orbits mean they go on to strike through the F ring on their own.
These small objects appear to collide with the F ring at gentle speeds – something on the order of about 4 mph (2 meters per second). The collisions drag glittering ice particles out of the F ring with them, leaving a trail typically 20 to 110 miles (40 to 180 kilometers) long. Murray's group happened to see a tiny trail in an image from Jan. 30, 2009 and tracked it over eight hours. The long footage confirmed the small object originated in the F ring, so they went back through the Cassini image catalog to see if the phenomenon was frequent.
"The F ring has a circumference of 550,000 miles [881,000 kilometers], and these mini-jets are so tiny they took quite a bit of time and serendipity to find," said Nick Attree, a Cassini imaging associate at Queen Mary. "We combed through 20,000 images and were delighted to find 500 examples of these rogues during just the seven years Cassini has been at Saturn."
In some cases, the objects traveled in packs, creating mini-jets that looked quite exotic, like the barb of a harpoon. Other new images show grand views of the entire F ring, showing the swirls and eddies that ripple around the ring from all the different kinds of objects moving through and around it.
"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 based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We can't wait to see what else Cassini will show us in Saturn's rings."
For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov/ and http://www.nasa.gov/cassini .
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colo. JPL is a division of the California Institute of Technology, Pasadena.
Guillermo Gonzalo Sánchez Achutegui
ayabaca@hotmail.com ayabaca@yahoo.com
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