Electric Saturn

[jjohnson]

Cassini took this photo in 2008. Various enhancements such as increasing brightness will show more "dusty light or ring'like stuff sunward beyond Saturn. This is one of the loveliest backlit photos the Cassini team has made. There is unlikely to be too much lens flare if the camera is well in the planetary shadow. There appears to be a solar artifact at the 7 o'clock position on Saturn's lower limb, but I don't know optics well enough to judge whether the spiky things are artifacts of that bright spot or not.

I think this image made the cover of Aviation Week & Space Technology magazine in 2008. That Earth was visible as a tiny blue dot made it a very popular image, like looking at a family portrait and spotting yourself in it.

[CharlesChandler]

Here is the standard "explanation" of Saturn's rings:

There are two main theories regarding the origin of Saturn's rings. One theory, originally proposed by Édouard Roche in the 19th century, is that the rings were once a moon of Saturn (named Veritas, a Roman goddess who hid in a well) whose orbit decayed until it came close enough to be ripped apart by tidal forces. A variation of this theory is that the moon disintegrated after being struck by a large comet or asteroid. The second theory is that the rings were never part of a moon, but are instead left over from the original nebular material from which Saturn formed.

It seems likely however that they are composed of debris from the disruption of a moon 400 to 600 km in diameter, bigger than Mimas. The last time there were collisions large enough to be likely to disrupt a moon that large was during the Late Heavy Bombardment some four billion years ago.

Both "theories" of the formation of the rings address the source of the material, but not the form. The rings extend up to 80,000 km above Saturn's surface, with an estimated local thickness of as little as 10 meters. It obviously took a force to organize that much matter into a near infinitesimal plane. The two fundamental forces operative at this scale are gravity and electromagnetism. As gravity cannot organize matter into a plane, the only candidate is some configuration of EM forces.

Saturn's magnetic field is very simple — it's a solenoid that is axisymmetric to a high degree of accuracy. We also know that magnetically-responsive matter (such as the diagmagnetic ice crystals in the rings) can only be accelerated where the lines of magnetic force are converging, and the acceleration is only in the direction of the convergence. Hence in a solenoidal field, there will be magnetic acceleration toward the poles, except on the equatorial plane. Thus the simplest explanation is that the rings represent just a slice of the entire debris field that once completely surrounded the planet, while the magnetic force eventually pulled all of the debris into Saturn via the poles, leaving just the equatorial plane where there was no net force.

Is this a unique idea, or has somebody thought of this before?

[nick c]

Very interesting hypothesis!
I have never heard of that before.

I don't know about the debris falling in at the poles leaving only an equatorial ring?
Possibly the orbiting debris repositions itself, due to the EM influences, in the equatorial plane. This same principle could be applied to the planets, which by and large orbit the Sun in the same plane, as well as several planetary satellite systems.

Birkeland simulated Saturn's rings in his terella experiments:
http://hal.archives-ouvertes.fr/docs/00 ... 07C408.pdf

Nick

[CharlesChandler]

For those interested, the following is a quote from the paper (pg. C4-120) that Nick cited:

His explanation of these rings was similar to that of the zodiacal light. A constant electric radiation from the planet is accompanied by an ejection of tiny material particles he called electric evaporation, and these particles form the rings. The laboratory analogy to this evaporation is what today is called sputtering.

Sputtering could (potentially at least) liberate a bunch of particles. But I'm not convinced that the matter so liberated from the planet would accumulate as we see in Saturn's rings, from 7,000 km to 80,000 km above the surface, and all on a perfectly flat plane. As such, this is just another theory concerning the source of the material, which does not adequately address the form of the material.

[CharlesChandler]

On the Electric Europa thread, StefanR did a posted called Re: Pole Shift on Europa? which talks about sputtering, and mentions an interesting article on it, in case somebody wants to follow up on that angle. I still thinking that sputtering could produce the material, but couldn't get it into the planar form of Saturn's rings.

[mharratsc]

Here's where I get confused: why do only the gas giants seem to have rings?

All planets (or should I say all dielectric spheres with a current flowing through them)seem to exhibit an equatorial toroid, but only the gas giants seem to exhibit ring formation.

Why? Anyone know? o.O

[orrery]

Here's where I get confused: why do only the gas giants seem to have rings?

All planets (or should I say all dielectric spheres with a current flowing through them)seem to exhibit an equatorial toroid, but only the gas giants seem to exhibit ring formation.

Why? Anyone know? o.O

This is not true. The inner planets do have rings they are just so thin as to be not be as observable.

[webolife]

Orrery,
Can you give me a source for that?

[CharlesChandler]

Here's a recent source that looks to be pretty authoritative, in case you want to pursue it. (I haven't read the whole thing yet, but I "think" that my "idea" has already been considered. I don't know about Orrery's statement.)

Burns, J. A.; Hamilton, D. P.; Showalter, M. R., 2001: Dusty Rings and Circumplanetary Dust: Observations and Simple Physics. In Interplanetary Dust. Berlin: Springer, 641-725

[mharratsc]

Here's where I get confused: why do only the gas giants seem to have rings?

All planets (or should I say all dielectric spheres with a current flowing through them)seem to exhibit an equatorial toroid, but only the gas giants seem to exhibit ring formation.

Why? Anyone know? o.O

This is not true. The inner planets do have rings they are just so thin as to be not be as observable.

According to Charles' reference, it seems like the first planet displaying noteworthy 'dustiness' is Mars, and it seems to display the dust toroidally, with bands within the toroid equating to the orbits of Phobos and Deimos (if I read all that correctly.)

I understand that the Earth is thought to have 'bands' (the Van Allen Belts) but again- that is more of a toroidal presence, and the disturbances within the toroid are hemispherical 'jet streams' with meteorological counterparts below them in the lower atmosphere.

Regarding fine dust- the moon is covered in fine dust, and when it becomes charged and lifts off the surface of the moon, it is easily visible with occular telescopes. Wouldn't you think we would be able to see backlit dust surrounding the Earth? We have satellites at the poles, at the equator... you would think that we would see at least some of the dynamics of dusty rings, if the dust in our orbital environment were actually organized into ring structures.

Is it possible that rings are a phenomenon that are only experienced by mid-orbital bodies?

Perhaps because the inner planets are more in equilibrium with the Sun, and the plutonian-orbit bodies are oppositely in equilibrium with the interstellar material, with Mars and Neptune showing some evidence of dusty organization, and Saturn, Jupiter and Uranus showing true 'ring' behavior due to their being the point of greatest charge nonequilibrium at the mid-shell distance between the Sun and the heliospheric boundary? o.O

[tamraherman]

I thought you were talking about the planet. ooopsss.. my bad.

[CharlesChandler]

Why do only the gas giants seem to have rings?

I still haven't read the reference in detail, but I picked up on a few interesting things just skimming it, which I'll be pursuing. First, they mentioned an electric current through the rings. This is a result of sunlight ionizing the ice crystals. And where do the free electrons go? The part of the rings that are in the shade are not getting ionized, so they absorb the excess charge. So we can expect the exposed aspect of the rings to be positively charged, and the shaded aspect to be neutrally or negatively charged. As the rings rotate, what is sunlit and what is in the shade changes, hence the "current" through the rings. They also mention that the sunlight is weak at that distance from the Sun, so the ionization and the electric current are weak. They suspect that more ionization occurs because the rings are bathed in interplanetary plasma.

Anyway, the implication of photoionization is that the closer to the Sun, the more positively charged the particles. Perhaps if you get too close (i.e., Martian orbit or closer), the rings get too highly charged, and then electrostatic repulsion blows them apart?

Another thing that (I think) they mentioned was that Saturn's magnetic poles are aligned with the rotational axis, unlike Earth wherein the magnetic poles are offset from the rotational axis. (Is that correct?) The significance of that for the idea that I was considering is that for the Earth, there isn't going to be this nice, neatly defined equilibrium at the magnetic equator. Rather, the magnetic equator is going to fluctuate radically with respect to the axis of rotation, and that's every 24 hours. As a result, there isn't going to be a consistent null plane in the magnetic field, with a bunch of particles lingering from the proto-planetary debris field that can't figure out which pole to approach. Rather, with magnetic fields sweeping back and forth every 24 hours through the axial equator, particulate matter would get accelerated back and forth, and there won't be a distinct ring.

[webolife]

Charles,
That is what I think as well... and pretty much must be the case if magnetic field equilibrium is the culprit for planetary rings. The earth is distinctive in the universe for sporting an artificial equatorial ring, ie. the GEO-stationary communications satellites, and those strictly by gravitational dynamics...

[ElecGeekMom]

IIRC, there is somewhere a thread about the tilt of the planets (not just Earth) being a phenomenon that occurs because of the influence of not just the sun, but also the energies from interplanetary sources.

I wonder if someone has created a graphic that illustrates the various tilts of the planets in our solar system?

[mharratsc]

@ Charles & Webo- you may be right, but I'm not going to be convinced that there isn't a (possibly quite large) influence of the heliospheric current density playing a part in the ring formations (or lack thereof).

I think if we could follow up on EGMom's suggestion and find a chart showing axial tilt and magnetic pole data for the planets, we'd be able to determine that plausibility right quick.