Posted on 07/21/2007 11:05:28 AM PDT by SunkenCiv
Saturn's vast and majestic ring system has its own atmosphere - separate from that of the planet itself, according to data from the Cassini spacecraft. And Saturn is rotating seven minutes more slowly than when probes measured its spin in the 70s and 80s - an observation experts cannot yet explain... By making close flybys of the ring system, Cassini has been able to determine that the atmosphere around the rings is composed principally of molecular oxygen (O2)... "The INMS sees the neutral oxygen gas, Caps sees the ionised products of that oxygen and the electrons associated with it. There is an enhancement over the rings," said Dr Andrew Coates, co-investigator for the Caps instrument, told the BBC News website... said the atmosphere was very similar to that of Jupiter's moons Europa and Ganymede. "As water comes off the rings, the hydrogen is lost from it, leaving the oxygen," he explained... Scientists admitted they were surprised by the finding that Saturn's rotation was slowing. "The rotation seems to have slowed down by about seven minutes compared with what was inferred from the Pioneer and Voyager data, but we don't actually understand why," said Professor Michele Dougherty, principal investigator for Cassini's magnetometer instrument.
(Excerpt) Read more at news.bbc.co.uk ...
Scientists Find That Saturn's Rotation Period Is A Puzzle
University of Iowa ^ | June 28, 2004 | Gary Galluzzo and Don Gurnett
Posted on 01/13/2005 9:00:04 PM EST by SunkenCiv
The currently accepted rotation period of Saturn came from radio measurements obtained during the Voyagers 1 and 2 flybys of Saturn in 1980-81, and is 10 hour 39 minutes and 24 seconds plus or minus 7 seconds. The first hint of something strange at Saturn came in 1997 when Alain Lecacheux, Patrick Galopeau, and Monique Aubier, from Observatoire de Paris, published a paper in the Austrian Academy of Science Press reporting that Saturn's radio rotation period was about one percent longer than the value obtained from Voyager. Now, during the Cassini approach to Saturn, where the radio signals from the planet are very strong and well defined, Gurnett and his colleagues have used the Radio and Plasma Wave Science (RPWS) instrument on Cassini to determine a new current value for the radio rotation period...10 hours 45 minutes and 45 seconds plus or minus 36 seconds.... Writing in the May 1985 issue of "Geophysical Research Letters," Alex J. Dessler, a senior research scientist at the Lunar and Planetary Laboratory, University of Arizona, argued that the magnetic fields of gaseous giant planets, such as Saturn and Jupiter, are more like that of the sun than of the Earth. The sun's magnetic field does not rotate as a solid body. Instead, its rotation period varies with latitude. Commenting on the work of Gurnett and his team, Dessler said, "This finding is very significant because it demonstrates that the idea of a rigidly rotating magnetic field is wrong. Saturn's magnetic field has more in common with the sun than the Earth. The measurement can be interpreted as showing that the part of Saturn's magnetic field that controls the radio emissions has moved to a higher latitude during the last two decades."
(Excerpt) Read more at uiowa.edu ...
Saturn's natural radio emissions raise questions about rotation
Bakersfield Californian ^ | 6/28/04 | AP - Pasadena
Posted on 06/28/2004 11:37:47 PM EDT by NormsRevenge
PASADENA, Calif. (AP) - The U.S.-European Cassini spacecraft has been listening to natural radio signals from Saturn, and what it's hearing raises questions about the length of day on the ringed planet. Cassini found the rhythm of natural radio signals, regarded as the most reliable indicator of the length of day, shows a complete rotation takes 10 hours, 45 minutes and 45 seconds, plus or minus 36 seconds, NASA said in a statement Monday.
That's about six minutes longer than the radio rotational period measured by the Voyager 1 and 2 spacecraft that flew by Saturn in 1980 and 1981. Similarly, observations made in France in 1997 also found a difference from the Voyager findings.
Cassini, due to enter Saturn's orbit Wednesday night, gathered radio data from April 29, 2003, to June 10, 2004.
"We all agree that the radio rotation period of Saturn is longer today than it was during the Voyager flyby in 1980," said Michael D. Desch, a member of the Cassini Radio Plasma Wave Science team and a scientist at the National Aeronautics and Space Administration's Goddard Space Flight Center.
But scientists don't think the whole planet is rotating more slowly now. Rather, they are looking for something deep inside Saturn that would cause variability in the radio pulse.
"Although Saturn's radio rotation period has clearly shifted substantially since the Voyager measurements, I don't think any of us could conceive of any process that would cause the rotation of the entire planet to actually slow down," said Don Gurnett, principal investigator for the Cassini Radio and Plasma Wave Science instrument at the University of Iowa.
Gurnett said there appears to be "some kind of slippage between the deep interior of the planet and the magnetic field, which controls the charged particles responsible for the radio emission."
On the Net:
Saturn's radio sounds:
http://www.jpl.nasa.gov/videos/cassini/0604/
(Stunning Saturn Pic) NASA finds Saturn’s moons may be creating new rings
Spaceflight Now | October 11, 2006 | NASA/JPL NEWS RELEASE
Posted on 10/12/2006 6:19:57 PM EDT by Names Ash Housewares
http://www.freerepublic.com/focus/f-news/1718366/posts
Scientists spot new ring around Saturn
AP on Yahoo | 9/20/06 | AP
Posted on 09/20/2006 8:00:55 PM EDT by NormsRevenge
http://www.freerepublic.com/focus/f-chat/1705224/posts
Cassini Finds ‘Missing Link’ Moonlet Evidence in Saturn’s Rings
JPL/ NASA | 3/29/06
Posted on 03/29/2006 11:18:01 PM EST by NormsRevenge
http://www.freerepublic.com/focus/f-news/1605910/posts
Saturn’s vanishing rings, and other surprises
Boston Globe | January 21, 2007 | Neil deGrasse Tyson reviewed by Anthony Doerr
Posted on 01/21/2007 11:31:26 PM EST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1771408/posts
Hot stuff on Saturn
University College London | January 29, 2007 | Fiona Davidson
Posted on 02/11/2007 9:34:29 PM EST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1783182/posts
The Electrical Heating of Saturn
Thunderbolts website | Mar 12, 2007 | unattributed
Posted on 03/13/2007 2:29:12 AM EDT by Fred Nerks
http://www.freerepublic.com/focus/f-news/1799937/posts
Water turned into ice in nanoseconds
UPI | 03/19/07
Posted on 03/19/2007 11:21:00 AM EDT by nypokerface
http://www.freerepublic.com/focus/f-news/1803231/posts
Bizarre Hexagon Spotted on Saturn
Space.com | 3/27/07
Posted on 03/27/2007 2:10:24 PM EDT by anymouse
http://www.freerepublic.com/focus/f-news/1807602/posts
Astronomers Find ‘Hot Spot’ on Saturn
AP on Yahoo | 2/4/05 | Jaymes Song - AP
Posted on 02/04/2005 12:33:28 PM EST by NormsRevenge
http://www.freerepublic.com/focus/f-news/1335997/posts
The spring is winding down.
It must be Global Warming from all those Space SUVs (SSUV.
Really interesting stuff! The rings with an atmosphere....
L
Sweet! I can’t even think of a sci-fi work that ever explored the prospect of a planetary ring with an atmosphere...
I think you’ve figured it out.
"The hydrogen is taken from the water by tiny elves with white beards," he explained.
"Oh, okay," said the old man working in his garden, "that must be where the tiny elves with white beards go during the daytime."
:’) It would be strange that no scifi writer has used that in two years since this story came out, but they’ve been too busy blaming the Bush administration for the rape of gaia and the murder of millions of moslems, plus fibbin’. ;’)
:’D
Uh-oh... the music from the Keebler cookies ad is starting to play here...
Have they found rings around Uranus, yet?
I think the youthful rings (see next post) must be made and destroyed all the time, but the mass is considerable, which suggests either an external source (capture), an internal source (shed by Saturn), or recycling (10 million unseen moonlets have been suggested).
::sigh:: I miss Heinlein...
Libetarian core, moralist, and a damned good writer. Explored so many details and at the same time brought you “there”.
SaturnThey range in size from a centimeter or so to several meters. A few kilometer-sized objects are also likely.
by Bill Arnett
The Nine Planets
Saturn's rings are extraordinarily thin: though they're 250,000 km or more in diameter they're less than one kilometer thick. Despite their impressive appearance, there's really very little material in the rings -- if the rings were compressed into a single body it would be no more than 100 km across.
The ring particles seem to be composed primarily of water ice, but they may also include rocky particles with icy coatings.
Voyager confirmed the existence of puzzling radial inhomogeneities in the rings called "spokes" which were first reported by amateur astronomers (left). Their nature remains a mystery, but may have something to do with Saturn's magnetic field...
The origin of the rings of Saturn (and the other jovian planets) is unknown. Though they may have had rings since their formation, the ring systems are not stable and must be regenerated by ongoing processes, perhaps the breakup of larger satellites. The current set of rings may be only a few hundred million years old.Saturn's Rings: FormationThe prevailing theory as to how Saturn's rings were formed comes from the 19th century astronomer Edouard Roche. Roche predicted that if an object such as a moon were to come too close to a large planet such as Saturn, eventually it would be torn apart by tidal forces - the uneven gravitational pull upon an object due to its size.
Adler Planetarium
2005
Under a tidal force, an object experiences a greater gravitational pull on its nearer side than its farther side. If the difference in force is great enough, this can cause a strain which literally breaks an object apart. Scientists now call this limit where an object will be torn apart by tidal forces the Roche Limit.Saturn's rings may be youngWhen the Voyager spacecraft swept past Saturn, they radioed back photos of a complex, very dynamic system of rings -- thousands of rings. Studies of these rings have led some astronomers to wonder if they are really as old as Saturn itself. Two lines of thinking suggest a recent origin:
by William R. Corliss
May-Jun 1985
(1) The rings are composed of both light material (very likely water ice) and dark material (probably rocks and dust). The rocky fragments, according to the prevailing nebular theory, should have condensed early in solar-system history, and then been swept gravitationally into the planet as they were slowed by friction with the uncondensed nebular material. Yet, dark material is still in the rings. (2) The incessant bombardment of the rings by meteorites should have pulverized the rings, sending fragments and vaporized material in all directions. In just 10 million years the rings should have been largely erased. They are still there.
(Cuzzi, Jeffrey N.; "Ringed Planets: Still Mysterious -- II," Sky and Telescope, 69:19, 1985.)
Uranus Ring Turns Out Blue
Wasn’t Larry Niven’s “Ringworld” a stellar ring construct with atmosphere, albeit artificial?
Yes, many. Also, Uranus is lopsided and gaseous. It has a massive moon and it’s own gravity.
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