Posted on 06/28/2004 8:37:47 PM PDT 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/
Saturn's radio sounds.
A ten hour day for a planet that size means it is rotating VERY rapidly, yes?
The Cassini-Huygens spacecraft returned this image of Saturn on May 16, 2004, when its imaging science subsystem narrow-angle camera was too close to fit the entire planet in its field-of-view. Culminating a nearly seven-year, 2.2 billion-mile journey through the solar system, NASA (news - web sites)'s Cassini spacecraft will fire its engine Wednesday, June 30, 2004, to slow down and allow itself to be captured by Saturn. (AP Photo/NASA) |
Saturn's Atmosphere and Rings
In this image, dark regions represent areas where Cassini is seeing into deeper levels in Saturn's atmosphere. The dark regions are relatively free of high clouds and the light at these particular near-infrared wavelengths (centered at 727 nanometers) penetrates into the gaseous cloud-free atmosphere and is absorbed by methane. The image was taken with the Cassini spacecraft narrow angle camera on May 15, 2004, from a distance of 24.7 million kilometers (15.4 million miles) from Saturn. The image scale is 147 kilometers (91 miles) per pixel. Contrast in the image was enhanced to aid visibility.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.
For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.
BTTT
This is a computer-rendered image of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane. This is a computer-rendered image of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane.
The SOI maneuver, which is approximately 90 minutes long, will allow Cassini to be captured by Saturn's gravity into a five-month orbit. Cassini's close proximity to the planet after the maneuver offers a unique opportunity to observe Saturn and its rings at extremely high resolution.
For a high resolution image, click here.
This artist's rendition shows the Huygens probe at the start of its 22-day coast phase toward one of Saturn's moons, Titan, as it is jettisoned from the Cassini spacecraft. Huygens will be the first probe to land on a world in the outer Solar System. The Cassini spacecraft is due to arrive and orbit the planet Saturn on June 30, 2004. JPL/Image by Steven Hobbs/Handout
This artist's rendition released June 28, 2004 shows the Huygens probe as it reaches the surface of Saturn's moon Titan. The Cassini spacecraft (top left corner of the image) flies over with its High Gain Antenna pointed at the probe. Saturn is seen in the background through Titan's thick atmosphere of methane, ethane and mostly nitrogen. Thin methane clouds dot the horizon, and a narrow methane spring or 'methanefall' flows from the cliff at left and drifts mostly into vapor. Smooth ice features rise out of the methane/ethane lake, and crater walls can be seen far in the distance. The Cassini spacecraft is due to arrive and orbit the planet Saturn on June 30, 2004. NO SALES REUTERS/NASA (news - web sites)/JPL/Image by David Seal/Handout
No, those signals emanate from Uranus.
"ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE"
Enhanced digital photos reveal that the rings of Saturn are actually composed of lost airline luggage.
(thank you Jay Leno)
YOu guys are funny, LOL.
All of this stuff still amazes me.
ping
If we could somehow arrange to tow that thing back, it would solve the natural gas shortage.
Note: this topic is from 6/28/2004. Thanks NormsRevenge.
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