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."

Comments

Re:This is simple

[GigsVT]

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".

Could be a particle rotation thing

[d00ber]

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.

Found non-Voyager proof

[Iron Sun]

About 30 seconds after posting the above I found this link, to an abstract of a scientific paper detailing Hubble observations of the spokes.

Re:Well, duh, haven't you read Niven?

[shadowbearer]

Actually I believe it was the intertwined out rings that they saw ("two earthworms mating") when the reporter Roger and a couple other characters were at JPL viewing the Voyager images. The two narrow rings were being roiled by the Message Bearer's drive, but of course we didn't know that at the time :)
The same chapter does refer to the spokes, but (pulls out copy to check) Yup, in the Prologue: "Outside the broad main ring system, a narrower ring still roiled from the wake of Message Bearer's drive". The first indication that *Earth* had of the oncoming ship was when they detected it, however; nobody could explain the rings.

I thought it was a neat way to refer to the Voyager images...

SB