Is Iapetus artificial?

[Karlos]

Dandy wrote:

falemagn wrote:
There's no reason for which crust expanding and shrinking should produce hexagons, ...

There's no reason for freezing water to produce hexagonal ice crystal structures either...

falemagn wrote:
... yet alone nested ones.

... yet alone snowflakes.

falemagn wrote:
And if you look at other pictures on the site, there are also examples of hexagonal craters being placed on a straight line, parallel to the ridge, at the same distance from one another.

Ever heard of/seen the impact of Shoemaker-Levy-9 on Jove a few years ago?
What's so hard to understand here?

falemagn wrote:
Also, crust expanding/shrinking can't explan the facets the moon seems to be made of.

Well - have you ever seen a "ball" formed of lots of soap bubbles?
Guess what shape the single bubbles have - they're hexagonally shaped!

Perhaps OT:

Hexagons are actually pretty common in nature.

The hexagonal geometry of ice and snowflakes is dictated by hydrogen bonding.

The hexagonal shape of a raft of soap bubbles arises from the fact that the hexagonal sheet gives you the most space efficient geometry (most bubbles per unit area). You can stack these hexagonally close packed sheets on top of each other (in 2 ways) to give two conformations known as HCP (hexagonally close packed) and CCP (cubic close packed). Sicne bubbles are not hard spheres, they will literally deform into an even denser arrangement that leaves no gaps and gives each bubble a tightlu defined geometry.

Take any number of equally sized hard spheres (eg marbles) and put them on a tray, shake it gently. You'll see them arrange themselves in the hexagonal pattern of a bubble raft (for exactly the same reason). Try to fill a volume with them and you will get either CCP or HCP overall. No other arrangement gives you the same packing efficiency (for hard spheres CCP/HCP is about 73 pecent or something).

[Karlos]

Yeah but saturn orbit isn't safe, that's the point. Especially for an object that size.

Saturn's outermost ring basically has no outer boundary, the particle density simply falls off the further away you get.

For a small object, the chances of being hit by debris are fairly slim at Iapetus distance, but for an object the size of Iapetus itself, well, you are going to get pummelled over time.

[Karlos]

Ah, the old exploding planet idea. The principal problem with that is, where is the mass now? If you add up the total known asteroidal mass in the solar system (that includes the asteroid belt, trojan clusters etc) there isn't enough to make a planetary body with the mass of our moon.

That would make it a moon of mars, not the other way around ;-)

Furthermore, there's not a great deal of iron floating loose out there, which you'd expect had any reasonably big (read earth sized or larger) planet violently tore apart.

One would also expect several stable belts of asteroidal debris (depending how long ago it happened), either side of where Mars is now.

Mars is also in a perfectly boring orbit, not particularly indicitave of an escaped moon (contrast to Pluto, for example). also, one would also expect a great deal of captured mass in orbit around it - phobos and deimos hardly constitute that.

IMHO the evidence for Mars being the surviving moon of a planetary catastrophe on this scale is completely inadequate.

[Karlos]

Quixote wrote:

Iron, well a number of the asteroids in the belt are mostly iron, while others have very little.  is there a better explanation for that?

Show me some large (as in comparable to Ceres, for example), near perfectly spherical iron-nickel asteroids that are more than 99.99% free metal and I'll take the idea of a planetary explosion more seriously. A planet large enough to have a moon the size of mars tidally locked in orbit would likely have a lot of free metal in the inner core that would be molten following such an event.

Large amounts of molten iron would adopt a spherical configuration pretty readily. Also, being the densest (therefore exerting the greatest gravitational field) part of the parent planet, I'd expect it to mop up a lot of the immediate debris too, so they'd be pretty damn large and hard to miss.

I can't think of a single known asteroid that fits the bill. The mass and inertia of such a body would preclude it being thrown in some wildly eccentric orbit never to be seen again.

Mars' orbit is rather tame(r) now, but it's still pretty elliptical.  Remember that over time, the influence of other worlds tends to smooth out a planet's orbit, making it more circular.

Tell that to Mercury and Pluto ;-)

As for two belts, one further in than Mars and one further out, you've missed it a bit:  Mars isn't in its original orbit; collisions with that much debris moving that quickly knocked it out of its orbit into a lower one.  The belt is at the original distance.  The asteroids are the bits that weren't moving quickly enough to shift orbit significantly, except over the eons.

The physics don't add up. The most massive parts of the planet would be near the core; these would be the ones hardest to move and also the ones with the most obvious compositional make up.

Unless of course, the force of the planetary explosion was so vast that it disintegrated it completely into small (no larger than say 100km) fast moving pieces.

Of course, the energy sufficient to do this would also obliterate any satellites. And I don't mean scarring them and ripping away their atmospheres. I mean total obliteration on the same scale as the parent planet.

[Karlos]

OK, ok, I admit it. It is artificial. I made it with an ACME Deathstar Construction Kit, but couldn't be arsed to finish it after cracking open the mold and realising I hadn't sealed it properly, causing some of the ice to bulge out around the join between the two halves.

[Karlos]

whabang wrote:
Screw-up!

That's why I left it around Saturn; I was hoping nobody would notice...

Frickin' Cassini Huygens :-x

[Karlos]

For what it's worth, Mr. Hoagland has added a page five

My god, he so needs to get laid or something :lol:

I've never seen such desperation.

[Karlos]

@Quixote

Aw come on matey, lighten up. Surely you can tell when I'm having a wee laugh :-)

Seriously, I confess I find the guys leaps of logic flawed.

If you ever watched Red Dwarf, you'll see Rimmer's total obsession with aliens. Anything even slightly strange happens, it's the work of aliens.

This is exactly how Hoagland behaves.

Consider the photographs he touts as proof of Iapetus' geodesic shape.

Every close photograph you see of it shows a perfectly normal limb against space, with the sole exception of the bulge in the middle. Only lighting seems to give any hint of a flat, geodesic structure, yet that flatness is not visible in any close range photographs at all.

Furthermore, this ridge would could not be the seemingly uniform profile we see if the overall shape were geodesic. The height at any point above the 'surface' would vary as you cross the vertices from one plane to another.

[Karlos]

It seems that some have begun with their conclusions, and are seeking data to support them, instead of the other way around.

This is *exactly* what Hoagland does every single time he sees something slightly strange.

[Karlos]

Ok,

If you are going to take the scientific approach, you need to be able to argue both sides of the coin.

Iapeteus is natural. Discuss.

[Karlos]

Quixote wrote:

@Karlos: requiring the other fellow to prove your position is another Ad Hominum argument, though I don't remember the Latin for it.  It amounts to "proof by assignment."

More later....

Not really, but I would expect it from someone unwilling to challenge their own viewpoint.

By attempting to prove the alternate argument you learn a lot about the validity of both.

This was standard practice during what would have been my doctorate.

During post experimental disscussion, whenever I had to propose a rationalisation for any observed result that had strong alternative rationalisation, I was required to try and prove both. If it didn't have a strong alternative rationalisation, I had to look for one (apart from the really obvious cases where it is totally evident what had occured).

This process keeps you objective and prevents you from becoming bogged down in any explanation that may seem to be  appropriate early on in an investigation, only to run into fundamental stumbling block later.

You'd be surprised how many times this process leads you to the correct interpretation (that can later be verified), even if it seems like more work.

Ad hominium, indeed :-)

[Karlos]

Quixote wrote:
;-) There is now more from Enterprise Mission.  Check out page six.

Fascinating stuff.

Wow, I take it all back :-o Hoagland truly has sussed it out this time! I'm convinced.





Yeah, whatever.