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.
Really interesting stuff! The rings with an atmosphere....
"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."
Have they found rings around Uranus, yet?
http://www.nineplanets.org/jupiter.html#khm
K. The heat is generated by the Kelvin-Helmholtz mechanism, the slow gravitational compression of the planet. (Jupiter does NOT produce energy by nuclear fusion as in the Sun; it is much too small and hence its interior is too cool to ignite nuclear reactions.) This interior heat probably causes convection deep within Jupiter’s liquid layers and is probably responsible for the complex motions we see in the cloud tops. Saturn and Neptune are similar to Jupiter in this respect, but oddly, Uranus is not.