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Saturn Rings But No Spokes
An anonymous reader writes "Scientists continue to ponder why images of Saturn's rings today lack the 'spokes' or dark radial bands radiating outward and first observed on the Voyager flyby. The Boulder-based Cassini Image Team describes 5 visible moons, plans for the descent probe going into the Titan moon's hydrocarbon-rich atmosphere and the expected orbital entry around Saturn less than 4 months from now."
If only NASA would bring the success of this mission into the public spotlight as a way to raise awareness as to its more successful programs.
That's absolutely true. After what happened with the Columbia, NASA really needs to boost public support for their programs. People see the 2 shuttle disasters that have occured as being the bulk of what they accomplished, and that is just wrong.
And of course, I'm not saying what happened isn't tragic. But people dont understand that many astronauts understand that disaster is a possibility, and they're willing to take that chance in the pursuit of the Greater Understanding.
NASA really has to get the PR machine in motion
Are you sure it would send the right message?
It sort of seems to me like saying "unmanned exploration is really successful, but look at how many people we killed with stupid manned exploration, that could have easily been done unmanned".
I've had enough abrasive sigs. Kittens are cute and fuzzy.
I'm sorry, maybe I'm just an idiot, but I don't really see any of the 'spokes' in the image you linked to.
Could somebody paste a big red arrow on there for the outer-space-cluefully-impared, such as myself?
Thanks.
There were no real current Astonomy Picture of the Day references so I linked to a search on Saturn. This gives quite a few different views of Saturn and some other related material as well.
Use your head, can't you, use your head,
You're on earth, there's no cure for that - S. Beckett
By the way, next summer NASA's Cassini spacecraft, launched in 1997, is scheduled to go into orbit around Saturn and its moons for about four years.
The piggybacking Huygens probe is scheduled to go into the hazy Titan atmosphere and land on the moon's surface (if all goes well). The Huygens probe is geared primarily towards sampling atmosphere. The probe is equipped to take measurements and record images for up to 30 minutes on the surface. But the probe has no legs, so when it sets down on Titan's surface its orientation will be random. And its landing may not be by a site bearing organics.
Please help publicise swpat.org - the software patents wiki
Obviously the Fithp has already left Saturn and is headed to Earth.
Time to start studying those old Orion plans...
The "spokes" are odd disruptions in the rings caused by Saturn's magnetic field rotating through them. They show up as dark patches radiating directly away from Saturn or occasionally arching, and they travel like a wave around Saturn in time with its rotation. It was this timing/speed that tipped astronomers off as to what was causing them, incidentally.
So if the spokes aren't visible now, maybe Saturn's magnetic field is fluctuating/less coherent than normal. It's a gas giant so its field could be less stable than the denser planets. There may be some low-level eg mid-atmosphere storm disrupting the normal field-generating circulations.
Just a thought. IANAA
cheers, Sal
--
Sal
Writings: saltation.blogspot.com
Wravings: go-blog-go.blogspot.com
Perhaps the spokes don't show up because they're not applying those same techniques? I certainly don't see any mention of those techniques in the article in the first link.
libertarianswag.com
This is an offtopic comment: offtopic because it was stolen verbatim from a totally unrelated story:
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.sig modded up
http://science.slashdot.org/comments.pl?sid=793
It's just an excuse to get the
TO BUY A NEW CAR WOULD MAKE YOU SEXUALLY ATTRACTIVE.
have been seeing spokes in the rings for quite some time using ground-based telescopes of various sizes. This may be one of those features, like the canals on Mars, that shows up because the eye-brain software processes images differently than the spacecraft ccd-computer does. An article in Sky & Telescope discovered they could reproduce the canal effects using the techniques of registration (stacking), and various applications of wavelets and other processing methods. They concluded our eye-brain mechanism does something similiar in real time at the eyepiece during moments of steady seeing conditions, causing dark lines to be seen where a smoother color gradient actually exists.
Saturn rang? And no one spoke with it? Geez, maybe it woulda told us everything.
But isn't that the truth? Let's face it, manned exploration IS orders of magnitude more expensive than unmanned, doesn't provide much more benefit from a scientific viewpoint, as is infinitely more tragic when things go wrong. If we still want to do manned exploration because of the "cool factor", then so be it, but let's not lie to ourselves about the facts.
I don't care if it's 90,000 hectares. That lake was not my doing.
It sort of seems to me like saying "unmanned exploration is really successful, but look at how many people we killed with stupid manned exploration, that could have easily been done unmanned".
Well, that's exactly the message many of us would like to get out. Using astronauts is hot stuff for the evening news but otherwise is rarely of much value. Even the "rescue missions" for things like the Hubble probably don't break even. The development and maintenance cost of the shuttles, space suits, manned safety environment, etc., has gotta be more than sending up full replacement systems.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Maybe a decent sized object passed through the rings, disturbed them and left.
Either that or some stoned punk aliens were waving their hands in front of the Voyager cameras just to screw with us.
This is my sig.
In all the APOD picture of Saturn I found a reference to Spokes and a picture that contains them.
Use your head, can't you, use your head,
You're on earth, there's no cure for that - S. Beckett
Agreed.
I think that a well-trained geologist/astronaut could pull far more information from a short walk on mars than those rovers could their whole time on the surface. Besides being infinitely more maneuverable than any robot, living astronauts can devise new experiments and fix things when they go wrong. Anything a robot can do, an astronaut in a space suit can do BETTER by several orders of magnitude.
Now, when things go wrong, it is much less tragic to lose a robot than it is to lose a space crew. However, any crew embarking on such an expedition will be fully cognizant of the risks, and I am sure that even if the trip was a guaranteed one-way ticket to mars that qualified volunteers could still be found.
I was a young engineer at JPL when Voyager 2 encountered Saturn, and I remember when the first photos of the spokes in the rings were displayed in real time on the monitors in the cafeteria. The work on other projects had pretty much ground to a halt while everyone watched the data come in.
Of course, the real time data had no captions, no explanations of what we were seeing, so we had all sorts of guesses - density waves, camera artifact, etc. Once it was apparent that the waves were holding together as the rings rotated and were not being sheared apart, it was clear they were not due to any gravitational effect. Since they moved with the rotation of the planet, the accepted explanation is the magnetic field of Saturn causing the charged dust in the rings to concentrate into visible spokes. As I understand it, the spokes are not a wave phenomenon at all.
I was wondering if the planetoid and particles could be doing the wave.
Generally these things are oblong rather than spherical. Maybe there is some gravitational coupling between the particle shape and Saturn and/or the other neighboring particles.
The particle could be spinning along their axes perpendiculr to the ring and along the line from the center of Saturn to the particle.
When the particles long axes are aligned perpendicular to the plane of the ring they would look one way (reflect less light perpendicular to the plane of the ring). Then when they rotate with the long axis in the plane of the ring they reflect more light perpendicular to the plane of the ring - they look brighter.
Admitttedly the dipole interaction would be pretty small. But this would allow for no spokes in the sense of ripples in the particle density but still allow us to "see" the spokes.
About 30 seconds after posting the above I found this link, to an abstract of a scientific paper detailing Hubble observations of the spokes.
When will Cassini photograph the monolith on Iapetus.
"dammit, we forgot the spokes. Quick, get that guy that colours the martian sky blue to add some in to the new pictures".