Origin of Saturn's Rings — from Inner Moons ???

[Widdekind]

Recent theories, regarding the origin of Saturn's rings, link them to that planet's icy inner moons — "the tiny particles that form the rings today... [are] pieces of moon" (Ron Miller. Saturn, pg. 32).

 

However, evidence indicates that the rings are relatively young:

There are many reasons that the rings are considered relatively young. One of these is how clean the ring particles are. The rings are very bright be/c the ice particles they are made of have not yet had time to be covered with dark dust. Another reason is that the gravitational effects of all of Saturn's moons — the same forces that create the thousands of large and small gaps in the rings — make the rings unstable. They look the way they do now only b/c the moons haven't had enough time yet to disrupt them.

A few million years from now

, however, the rings will start to fall in toward Saturn, ad the solar system will lose one of its greatest natural wonders

(Ron Miller,

ibid

.)

.

 

Now, it is also suggested, that some of Saturn's icy inner moons may mount geysers, powered by tidal heating:

Some astronomers have speculated that Enceladus may have geysers, powered by the heat generated beneath the surface of the moon due to tidal flexing caused by nearby Saturn

(Ron Miller,

ibid

., pg. 64)

.

 

CONCLUSION (??): Could the constant tidal heating, of the icy inner moons by Saturn, create constant geysers, whose high speed streams escape those moons' weak gravities, and constantly replenish the rings (as fast as the fall inward) ?? If so, then, in-so-far as the icy inner moons' supplies of volatiles has decreased over the eons, Saturn's rings may have been bigger & brighter in the dim & distant past.

 

Ice Fracture on Enceladus —

Voyager

photos in

1979 AD

showed that Enceladus has more

pronounced fracturing and resurfacing

than other Saturn moons. Here we look along a

geologically young fracture

toward Saturn, which subtends 29°. Angular width: 45°.

(

Out of the Cradle

, pp. 158-159.)

 

Eruption on Enceladus —

The brightness of Enceladus' ice, its sparsely cratered, fractured plains, and the nearby

E Ring

of ice crystals, [all] suggest that Enceladus may be geologically active. Here an eruption of water & vapor blows a fresh supply of ice crystals off Enceladus and into the

E Ring

.

(

Out of the Cradle

, pg. 163.)

 

Eclipse of the sun seen from Tethys —

Reddened by shining through Saturn's atmosphere, the Sun casts a sunset glow across Tethys' [cratered] ice fields. The puzzling moon Enceladus, covered by the brightest ice in the solar system, is at upper left. The Sun backlights the mysterious

E Ring

, a fuzzy extension of Saturn's main ring system. The

E Ring

consists of microscopic ice crystals, concentrated along Enceladus' orbit, which may be evidence of fresh ice-volcano eruptions blowing material off Enceladus. Angular width of wide-angle view: 70°.

(

Out of the Cradle

, pp. 160-161)

 

 

 

 

Our legacy on Mimas —

Seeking clues as to whether icy Mimas was completely disrupted & reassembled one or more times, by the intense cratering it has undergone due to meteorite impact, explorers have left their mark on this innermost of Saturn's sizeable moons. Saturn, subtending 39°, covers much of the sky.

(

Out of the Cradle

, pg. 162.)

 

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Uranus is known to have 21 moons and 9 "thin wispy" rings; Neptune is known to have 8 moons and 4 "very narrow" rings (Ron Miller. Uranus & Neptune, pp. 35,43,52,56). It is also likely that the ring particles are "smashed moon... debris [which] would have provided material for Neptune's rings" (ibid., pp. 46). And, tide-generated geysers are known to exist on Neptune's moon Triton (ibid., pg. 51)

 

CONCLUSION (??): These facts are completely consistent w/ claims, that tide-generated geysers on moons, spew out volatile materials, which make up the parent planets' rings. Indeed, fore the aforesaid Ice Giants, the number of rings (8,4) correlates closely with the number of moons (21,8), in a ratio quite close to 2:1. Indeed also, Saturn sports some 62 moons, many more than either Ice Giant, again completely consistent w/ these claims*. Moreover, since said Ice Giants are much less massive than Saturn, they generate weaker tidal forces, which would generate weaker geysers, which would explain the Ice Giants' far fainter ring systems. Moreover still, these dramatically reduced ring replenishment rates easily explain the "very dark" appearance of the Ice Giants' rings, in stark contrast to Saturn — "[the rings] are very dark, resembling powdered coal more than the chunks of [fresh] ice that make up Saturn's rings" — since the Ice Giants' rings have had more time to sweep up dust than those of Saturn.

*

Jupiter

boasts

63

moons, but only

8

are regular satellites (which formed along with their parent planet), whilst "

Jupiter's other

55

moons are irregular satellites, whose prograde and retrograde orbits are

much farther from Jupiter

and have high inclinations and eccentricities [and] were likely captured by Jupiter from solar orbits

". Somewhat similarly,

Saturn

sports

24

regular moons, whilst "

the remaining

38

, all small save one, are irregular satellites, whose orbits are

much farther from Saturn

, have high inclinations, and are mixed between prograde and retrograde [and which] were likely captured minor planets, or debris from the breakup of such bodies after they were captured, creating collisional families

". Thus, Saturn sports

three-times more

moons, on regular interior orbits near its rings, than Jupiter, yet again completely consistent w/ these claims. Moreover, since Jupiter is much more massive, and generates significantly stronger tides, its inner moons may be "dynamically older", having finished venting off their volatiles

long ago

, leaving Jupiter's rings

today

in something of a state of "slow decay", well past their prime.

 

 

PREDICTIONS:

1. Geysers indicate that moons are molten in the middle. Such is associated w/ volcanic and other "planeto-thermal" activities which rapidly resurface those moons. Thus, rings, being linked to geysers, ought to be linked to young surfaces on the moons near those rings.
   
2. Neptune's moon Triton orbits retrograde, at high inclination, well away from its parent planet's rings. Yet, geysers still spew from its surface. So, unless Triton's exceptional size & gravity re-capture all of that ejecta, Neptune should show some sort of ring associated w/ Triton's orbit.

In-so-far as "young moon surfaces" are associated w/ ring systems, then the most spectacular rings around ought to be in young, freshly formed, star systems. To wit, "somewhere out there", is a super-Saturnianly-spectacular ultra-ring system, waiting for Astronomers & Exoplanetologists to take its picture.

 

 

 

 

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Jupiter's rings are "dark", resembling dust, and are "closer to Jupiter than its moons" (Ron Miller. Jupiter, pg. 48). This is completely consistent w/ Jupiter's rings being "dynamically older" than those of Saturn (and even the Ice Giants), since Jupiter's super-tides long ago boiled off the volatiles from Jupiter's inner-most moons, whose once-mighty (?) ice geysers now stand silent & extinct. Thus, Jupiter's faint dusky rings are already past their prime, in a state of inexorable decline, sliding ever planet-ward.

 

Indeed:

Jupiter has a ring of microscopic, dark-colored particles extending inward from the region of four small moons that line inside Io's orbit. The largest of these moons, Amalthea, is a potato-shaped lump about 155 x 200 km (97 x 125 mi). It has a reddish color, possibly derived from sulfur materials knocked off Io by meteorites or energetic atomic particles. The other moons are much smaller: 35 to 75 km (22 to 47 mi) across.

Tiny particles knocked off these moons, especially the one on the very edge of the ring [Metis], would spiral in toward Jupiter, and may be the source of the ring

. In this view, the ring with its inward flow of particles would be like a [inwardly spiraling] river — always there, but containing different material at each moment... from the ring's fuzzy inner edge, to its sharp out edge near the moonlets' orbits

(W.K. Hartmann, R. Miller, P. Lee.

Out of the Cradle

, pg. 152)

.

 

Again, this agrees with our previous picture of the process.

 

 

 

 

 

 

 

 

In Jupiter's Ring —

We float above a small moonlet (bottom) at the outer edge of Jupiter's thin, enigmatic ring of dark, stony particles. Looking toward Jupiter, we see the surreal cloud pattern of Jupiter's

Red Spot

(top) and the gray ring stretching away thousands of miles into the distance (bottom half), creating its own 'horizon'. The ring is thin enough that we can dimly see through it.

(

Out of the Cradle

, pg. 152.)

 

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The early Earth possessed a ring, of dust & debris, in the wake of the Moon-forming impact, roughly 4.5 Gya:

The collision probably took place when the Earth was only about half formed.

The impact threw a ring of very hot debris into orbit around the young Earth

. The Moon probably formed by accretion very quickly from this debris, perhaps in

fewer than 10 years

... The newly formed Moon began to gradually spiral farther & farther away from Earth.

One hundred million years after its creation — 4.4 billion years ago

— the Moon was already half-way to its present distance

(Ron Miller.

Earth & Moon

, pp. 17-19)

.

 

This strongly suggests, that any process which deposits dust & debris, into orbit about a particular planet, causes the creation of a ring. Likewise, if that process is, itself, ongoing, then it can maintain that ring.

 

 

 

 

 

 

Note that ring systems seem inherently unstable, falling ever inwards. For, so much of that dust & debris, in Earth's brief ring, fell into Earth's upper atmosphere, that it darkened Earth's skies for roughly 300 million years:

 

4.4 billion years ago

... the sky would have been dark because of the high-altitude layer of dust

[infalling from the Earth's dusty debris ring, as well as relic dust from the Sun's planetary disk]

... The sky began to brighten

about 4.2 billion years ago

, even though asteroids still fell

(

ibid

., pg. 24)

.

 

Earth's skies may not have cleared completely until after 3.8 Gya (ibid., pp. 28-29).

 

 

 

 

 

Edited March 12, 2010 by Widdekind
Consecutive posts merged.

[Widdekind]

Not new (in essence) ??

 

Jupiter's rings formed by dust from small moons

 

Jupiter's intricate, swirling ring system is formed by dust kicked up as interplanetary meteoroids smash into the giant planet's four, small inner moons, according to scientists, three of them from Cornell, studying data from NASA's Galileo spacecraft. Images sent by Galileo also reveal that the outermost ring is actually two rings, one embedded within the other...

 

"Rings are important dynamical laboratories to look at the processes that probably went on billions of years ago when the solar system was forming from a flattened disk of dust and gas," Burns explained. Furthermore, similar faint rings probably are associated with many small moons of the solar system's other giant planets. "I expect we will see similar systems at Saturn and the other giant planets," Burns said.

 

Jupiter's rings formed by dust from small moons

Edited March 17, 2010 by Widdekind

[Widdekind]

From Astronomy: A Visual Guide by Mark A. Garlick:

 

The Rings of Jupiter

 

The rings of Jupiter are extremely sparse, especially in comparison to Saturn. In fact, they are not at all visible from Earth, and even from the Jupiter system itself, you would only spot them clearly if you were within the shadow of the planet. Jupiter's rings consist of three components -- the Halo ring, the Main ring, and the Gossamer ring. Unlike the rings of all the other planets, those of Jupiter are made of tiny fragments of rock comparable in size to particles of smoke. The pressure of the Sun's radiation, and also the strong magnetic forces at work within the Jovian environment, regularly remove some of these fleeting particles, since they are very lightweight. However, the ring system is most likely maintained through the regular action of meteorite impacts on the surfaces of the Jovian satellites. Dust kicked up during these impacts is thrown into orbit around Jupiter, and eventually repopulates the rings.