Iapetus (APOD 01 Feb 2005)

[craterchains]

February 1, 2005 APOD Iapetus

That nobody commented on this APOD photograph taken by Cassini amazes me even more than the photo of Iapetus. As Cassini entered the Saturn moon system on it's initial slowing down passes it managed to come close to this body orbiting Saturn. APOD also has a picture of Iapetus from the Voyager space craft shown on October 15, 1995.

Iapetus is quite interesting in many ways, and oddities make it stand out as very unique in other ways.

Norval

[makc]

could it be formed from two smaller bodies?

[Kid]

Is it possible that an asteriod hit iapetus and rip out all the surrounding rocks but it stops at the ridge and the rock thrown off the surface became Saturn's rings?

[craterchains]

Could it be from two smaller bodies?
That rings a bell about how big and dense an object must be before it will naturally mold itself into a ball shape from it's own gravity. I think Iapetus is about 900 miles? That is a possibility I think also, but I doubt it is the answer.

Kid has a fresh idea, but the angles and trajectories presented shuts that thought down. Study more about crater formations Kid, they tell us a whole lot more than just being holes in the surface. But, that also brings up the idea of something massive skidding along the surface and creating said "mountain range" that is about 20 kilometers high and some 800 kilometers long? Good input.

Norval

[Kid]

Could it be from two smaller bodies?
That rings a bell about how big and dense an object must be before it will naturally mold itself into a ball shape from it's own gravity. I think Iapetus is about 900 miles? That is a possibility I think also, but I doubt it is the answer.

But how did it get its gravity?

[Bad Buoys]

But how did it get its gravity?

By existing.
It is a force of attraction and exists between all objects in the universe.
Newton found that the force of gravity on an object is directly proportional to its mass.

The density of Iapetus is 1.1 indicating that it is almost wholly of something akin to water based ice.
The heat generated by a collision could have allowed both colliding ice objects to flow together into a sphere before re-freezing, as you speculate.

The ridge is thought to be either a fold in the solidified surface as the interior continued to cool, or an eruption of internal material [water?] through a fissure which cooled and solidified as it was spewed up.

But such a long straight ridge almost exactly on the equator is surely a provocative anomaly.

And what of the large fissure looking objects in the lower right? Is that just the lighting on another, larger crater wall or a collapsed piece of the surface as the interior continued to cool and shrink?

[craterchains]

Bad Bouys wrote;
"But such a long straight ridge almost exactly on the equator is surely a provocative anomaly."

Another, as you said, "provocative anomaly" is that Iapetus orbits almost a million miles out past the other moons and rings of Saturn. And, at a 15 degree off set from the others.

Here are some more pages and pictures of Iapetus for those that are as intrigued as I am with this small solar body.

http://photojournal.jpl.nasa.gov/catalog/PIA06165
http://photojournal.jpl.nasa.gov/catalog/PIA06167
http://photojournal.jpl.nasa.gov/catalog/PIA06168
http://photojournal.jpl.nasa.gov/catalog/PIA06170
http://photojournal.jpl.nasa.gov/catalog/PIA06171
http://photojournal.jpl.nasa.gov/catalog/PIA06146


Iapetus has also been heavily bombarded as many of Saturn's moons have shown.

[craterchains]

I would like to know where these pictures came from?
http://www.enterprisemission.com/moon4.htm

[Empeda]

Luke took them - just before going in to atttack.......

[makc]

Nah, I still think this is better.

[craterchains]

Anybody have any idea where Hoagland got those pictures from?

[BMAONE23]

SATURN AND MOONS
http://www.nasa.gov/mission_pages/cassi ... ive_1.html
IAPETUS
http://search.nasa.gov/search/search.js ... de=IAPETUS