Saturn's new moon reminded me of one of my favorite solar system objects - another moon of Saturn called Iapetus (pictures below). The ridge is pretty impressive. It's about 12 miles high and 1300 miles long and right at the equator.

I've never read a good explanation of how this ridge was formed. Anybody here have their own theories about it? My favorite is that it's a giant walnut placed in orbit around Saturn by our alien friends (but that's just me).
;-)

Way out in the Oort Cloud there is this gigantic Walnut tree. . . ;o)

---

Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

A lot of debris in the Saturn system, around its equatorial plane, hence its rings and *many* moons. Two other small moons of Saturn, Atlas and Pan, have even larger equatorial ridges, in comparison to their diameters, than Iapetus. They are imbedded in the rings. Iapetus is much further out. Accretion of debris after the moons solidified, so that it piled up on their surfaces is suggested. A collision of small moons near Iapetus may have supplied the material for its ridge. Michael

As a follow up, I might add that the mysterious dark hemisphere of Iapetus, called the Cassini Regio, after is discoverer, is the same hemisphere that contains the equatorial ridge. An interesting coincidence. These two features may have a single origin. As the recent collision of two communications satellites has shown, a single impact can produce two separate debris fields, one much more narrowly confined in its orbit than the other. It seems possible that two small bodies collided in the congested area around Saturn and left two such concentrations of debris near Iapetus. These could have fallen to the surface, one forming a narrow ridge, the other a broad plane. It is interesting to note that the dark region of Iapetus is actually an equatorially distributed field, like the ridge, just *much* broader; the sections or the polar areas facing the dark side are light colored. It even seems possible that the impact of material forming the ridge could, by itself, have released a dark, relatively fine dust which covered much of the hemisphere, eliminating the need for a second, broad debris field. Michael

Maybe the ridge on Iapetus has something to do with the junk being deposited there making one side almost white, the other dark.

---

Fluid dynamics + angular momentum + Newtonian mechanics.

Crap, do I really need to provide wiki links for this?

Holy heck, you people are supposed to be smarter than I am.

Think it all the way through with the physics you already know!

---

Pure mathematics is, in its way, the poetry of logical ideas.

Albert Einstein

kenzieB, Was the ridge on Iapetus caused by tidal forces, as your remarks seem to indicate? While it is conceivable that the ridge is the eroded remnant of a tidal bulge, this is merely one of several possibilities, all are worthy of consideration, and are receiving same. The tidal bulge theory has several problems. 1. The known oblateness of Iapetus is that of a rapidly spinning body, despite its current slow rotation. Additional tidal bulge at the equator would indicate an atypically rapid rotation, which itself would require an explanation. 2. The ridge on Iapetus exists on only one side of the planet. How is it that it is does not reach all the way around the moon, if it is tidal in nature? 3. The erosion of such a substantial portion of the moon, on a small sphere, not known to be geologically active seriously needs an explanation. It would have to account for the absence of a layer of material as thick as the ridge, on the equator of the opposite hemisphere. It would also have to account for a layer of material averaging half as thick as the ridge over the rest of that hemisphere, *and* over the dark hemisphere, excluding the area of the ridge itself. Michael

. . . it's the 'vertebrae' of THAT Intelligence FaCtor ;)

---

BOINC Wiki . . .

Science Status Page . . .

The answer should lie in saturns gravitational pull and the varying density of the surface that makes up the moon or possibly in the past it could have been molten at one point

---

We choose to go to the moon and to do other things, we choose to go to the moon not because its easy but because its hard. kennedy

Way out in the Oort Cloud there is this gigantic Walnut tree. . . ;o)

LOL good one =)

---

Nobody is nobody. Everyone has something to offer