Cassini Reveals New Ring Quirks,

[Savwafair2012 Profile]

Of the countless equinoxes Saturn has seen since the birth of the solar system, this one, captured here in a mosaic of light and dark, is the first witnessed up close by an emissary from Earth ... none other than our faithful robotic explorer, Cassini. (Credit: NASA/JPL/Space Science Institute)

NASA scientists are marveling over the extent of ruffles and dust clouds revealed in the rings of Saturn during the planet's equinox last month. Scientists once thought the rings were almost completely flat, but new images reveal the heights of some newly discovered bumps in the rings are as high as the Rocky Mountains.

NASA released the images Monday.

"It's like putting on 3-D glasses and seeing the third dimension for the first time," said Bob Pappalardo, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This is among the most important events Cassini has shown us."

On Aug. 11, sunlight hit Saturn's rings exactly edge-on, performing a celestial magic trick that made them all but disappear. The spectacle occurs twice during each orbit Saturn makes around the sun, which takes approximately 10,759 Earth days, or about 29.7 Earth years. Earth experiences a similar equinox phenomenon twice a year; the autumnal equinox will occur Sept. 22, when the sun will shine directly over Earth's equator.

For about a week, scientists used the Cassini orbiter to look at puffy parts of Saturn's rings caught in white glare from the low-angle lighting. Scientists have known about vertical clumps sticking out of the rings in a handful of places, but they could not directly measure the height and breadth of the undulations and ridges until Saturn's equinox revealed their shadows.

"The biggest surprise was to see so many places of vertical relief above and below the otherwise paper-thin rings," said Linda Spilker, deputy project scientist at JPL. "To understand what we are seeing will take more time, but the images and data will help develop a more complete understanding of how old the rings might be and how they are evolving."

The chunks of ice that make up the main rings spread out 140,000 kilometers (85,000 miles) from the center of Saturn, but they had been thought to be only around 10 meters (30 feet) thick in the main rings, known as A, B, C, and D.

In the new images, particles seemed to pile up in vertical formations in each of the rings. Rippling corrugations -- previously seen by Cassini to extend approximately 804 kilometers (500 miles) in the innermost D ring -- appear to undulate out to a total of 17,000 kilometers (11,000 miles) through the neighboring C ring to the B ring.

The heights of some of the newly discovered bumps are comparable to the elevations of the Rocky Mountains. One ridge of icy ring particles, whipped up by the gravitational pull of Saturn's moon Daphnis as it travels through the plane of the rings, looms as high as about 4 kilometers (2.5 miles). It is the tallest vertical wall seen within the rings.

"We thought the plane of the rings was no taller than two stories of a modern-day building and instead we've come across walls more than 2 miles [3 kilometers] high," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colo. "Isn't that the most outrageous thing you could imagine? It truly is like something out of science fiction."

Scientists also were intrigued by bright streaks in two different rings that appear to be clouds of dust kicked up in collisions between small space debris and ring particles. Understanding the rate and locations of impacts will help build better models of contamination and erosion in the rings and refine estimates of their age. The collision clouds were easier to see under the low-lighting conditions of equinox than under normal lighting conditions.

At the same time Cassini was snapping visible-light photographs of Saturn's rings, the Composite Infrared Spectrometer instrument was taking the rings' temperatures. During equinox, the rings cooled to the lowest temperature ever recorded. The A ring dropped down to a frosty 43 Kelvin (382 degrees below zero Fahrenheit). Studying ring temperatures at equinox will help scientists better understand the sizes and other characteristics of the ring particles.

The Cassini spacecraft has been observing Saturn, its moons and rings since it entered the planet's orbit in 2004. The spacecraft's instruments have discovered new rings and moons and have improved our understanding of Saturn's ring system.

The Cassini-Huygens mission is a cooperative project of NASA and the European and Italian Space Agencies. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington. JPL also designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team is based at the Space Science Institute. The Composite Infrared Spectrometer team is based at NASA's Goddard Space Flight Center in Greenbelt, Md.

To view Cassini images of the equinox and for more information about the mission, visit http://www.nasa.gov/cassini .

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[Savwafair2012 Profile]

Okay Marduk you should have caught this

[Savwafair2012 Profile]

what no comment from the Duke ?

[Pindz Profile Website]

Very Nice Post !

[Savwafair2012 Profile]

Very Nice Post !

[Torofamily Profile]

Good job sabwafair

[-Marduk- Profile]

what no comment from the Duke ?

Of course great post, Sav ...Saturn my fav topic...I also posted sis on my Saturn thread ...but you have way better photos. Great Can I copy your post into my Saturn thread, Sav?

Saturn Equinox Reveals Mountains in Rings




The fortuitous lighting of Saturn’s equinox has revealed the planet’s famously smooth, flat rings are actually corrugated. During the days immediately after the August 11 equinox, the sun’s rays struck the rings at very low angles, bringing their topography into high-relief.

For scientists studying the rings, the event happening once every 15 years provided an unprecedentedly dimensional view of the rings. They were thought to be about 30 feet thick — and they are, generally speaking — but the Cassini spacecraft has revealed regions that are nearly two miles high. “Like the seas of Earth, this wide icy expanse has settled into a mathematically precise cast that, here and there, froths and churns, not by wind but by the convulsive forces of Saturnian moons,” Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, wrote in her Captain’s Log. “This famous adornment, impressed deep in the human mind for four centuries as a pure, two-dimensional form, has now, as if by trickery, sprung into the third dimension.” There are several different types of clumps and corrugations and walls within the rings. Scientists have different theories about how the structures might form. Some of them, they know, are caused by Saturn’s moons.

“It turns out that as the orbits of the moons are a little inclined relative to the ring plane, they pull the particles out of the plane,” said Linda Spilker, Cassini deputy project scientist at the Jet Propulsion Laboratory in Pasadena, California. In the picture above, the ring mountains can be seen at the upper right casting a shadow on the gray ring to the right. They were pulled up out of the ring plane by the moon Daphnis. Other structures seen in the rings are more mysterious. Corrugations across the C and D rings could have been caused by a collision with some kind of space object, but Spilker said the Cassini team isn’t sure about that. In general, the scientists were surprised by the amount of height variation within the rings, most of which they were only able to see because of the good timing of the mission.

“It was very lucky that we had Cassini at the rings at the right time,” Spilker said. The image at the top of the post shows Saturn a day and a half after the equinox. It has been enhanced to increase the drama of the view, and Porco provided a wonderfully detailed explanation of how the image was created. “To improve their visibility, the dark (right) half of the rings has been brightened relative to the brighter (left) half by a factor of three, and then the whole ring system has been brightened by a factor of 20 relative to the planet,” Porco wrote. “So the dark half of the rings is 60 times brighter, and the bright half 20 times brighter, than they would have appeared if the entire system, planet included, could have been captured in a single image.”


http://www.wired.com/wiredscience/2009/09/saturn-rings/

[Savwafair2012 Profile]

No worries

Lots of cool pic's here.
http://www.nasa.gov/cassini .