Friday, May 13, 2005

Have we cracked Saturn's walnut?

"According to Freire, debris from the ring smashed into a narrow region along the moon's equator, piling up to create the ridge. Consistent with his claim that the moon only grazed the ring is the fact that the ridge does not extend over the entire hemisphere. If the moon had fully entered the ring, a ridge would have formed over a 180-degree arc of the equator, he argues."

Good point. However:

"But Larry Esposito, a specialist on planetary rings at the University of Colorado in Boulder, points to a major flaw in Freire's idea. Today, Iapetus's orbit is far outside Saturn's rings and not even in the same plane as they are, making it unlikely that Iapetus ever collided with a ring, he says."

I'm quite positive Richard Hoagland will have this cleared up in no time ;-)

5 comments:

JohnFen said...

The link didn't work for me, so i'll just comment on the excerpt because I'm lazy.

It's an interesting theory. One way to test it would be to look at the meteor crater density. Assuming that Saturn's rings are narrow enough to account for the narrowness of the bulge (is that true?), the rings are still not perfectly knife-edged. There should be a high density of meter impacts from the rings that tapers off as you get further from the equatorial ridge. Is there?

Mac said...

Not that I can tell.

Anonymous said...

johnfen -- The link is broken but once you're at New Scientist you can easily find the article, which isn't far down the list on the Home page. The biggest objection to Freire's ring-whack theory (brought out in the article) is pretty telling. As Larry Esposito (former Bruin's hockey star Phil Esposito's much youger brother 8-)Iapetus' orbit is nearly a million miles out from Saturn. Hard to explain how this moon got close enough to the rings for the Wall to happen by collision and then went that far back out again. Iapetus' orbit is also inclined to the plane of the rings.

arcesilaus -- Interesting theory. Personally, I do think all the "natural" possibilities should be exhausted before we start thinking artificial. For example, if Iapetus was produced by the collision of two roughly equal-sized bodies, this might have created enough pressure in the middle to extrude an equatorial ridge and also account for Iapetus' excessively oblate shape. On the artificial side, though, it is intriguing that part of the Wall shows 3 exactly parallel ridges that do give this particular section a distinctly "artificial" look -- my own pet theory is that it's the housing of a tunnel for an electromagnetic spacecraft launcher, which would also account for it's only going partway around Iapetus.

Mac said...

The EM "railgun" idea occurred to me, too...

Buy Cialis said...

exactly what is the material that are made it the space rings? I hear that ice and rocks, but I think that there's more, not only those two.