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  #91 (permalink)  
Old 07-January-2005, 05:09 AM
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Quote:
Originally Posted by ToSeek
Since the leading side of Iapetus is dark, while the trailing side is bright, the generally accepted belief is that it's a bright moon that has picked up dark material while orbiting.
That would also be consistent with Pheobe forming a dark crust over lighter matter - assuming it is a recent acquisition that was rotating when it was captured.

On the other hand, Rhea looks like it was hit by something white, so if there is also white stuff floating around, a completely dark coat on the leading side is inconsistent with 'white stuff' collisions.

Isn't this a great puzzle?
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  #92 (permalink)  
Old 10-January-2005, 05:15 PM
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Lots about Iapetus:

Giant landslide

View from the top

Encountering Iapetus
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  #93 (permalink)  
Old 11-January-2005, 02:19 AM
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VIMS Shows Iapetus Surface Composition



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The different colors represent vastly different surface compositions. The upper bright blue region is rich in water ice, while the lower, dark brown region is composed mainly of a substance rich in organic material. The yellow region consists of a mixture of ice and organics, suggesting a gradual change in composition on the surface. This pattern suggests Iapetus swept up the dark material, which may have come from debris created from meteoritic impacts onto the small, outer satellites of Saturn.
Iapetus Surface Composition



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The color composite shows water as blue, carbon dioxide as green, and non-ice minerals as red.
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  #94 (permalink)  
Old 11-January-2005, 09:42 AM
Ari Jokimaki Ari Jokimaki is offline
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Quote:
Originally Posted by ToSeek
Since the leading side of Iapetus is dark, while the trailing side is bright, the generally accepted belief is that it's a bright moon that has picked up dark material while orbiting.
If that would be the case, then shouldn't we see it in other moons also? Or is Iapetus only moon bright enough to show this effect?
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  #95 (permalink)  
Old 11-January-2005, 10:24 AM
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Actually, Dione and Rhea have brighter leading hemispheres, but it looks like some other process is at work than what happened at Iapetus.
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  #96 (permalink)  
Old 14-January-2005, 09:40 AM
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Stange Hyperion



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This unusual view of Saturn's moon Hyperion shows just how strangely shaped this tumbling little moon is. Hyperion is thought to be the largest irregularly-shaped moon in the solar system. Hyperion is 266 kilometers (165 miles) across.
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  #97 (permalink)  
Old 17-January-2005, 11:40 AM
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I hope they will put the Cassini raw image gallery back online soon, since yesterday (Sunday) Cassini flew past Mimas, Enceladus, and Rhea hopefully taking best pictures of them yet.

Just checked: Here they are!
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  #98 (permalink)  
Old 17-January-2005, 11:48 AM
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Mimas with Herschell Crater clearly visible (it's surprisingly rough)
Closer view, Herschell at the terminator

Gibbous Enceladus
Crescent Enceladus: this moon is really weird!

Rhea

(There may be even better views, I don't have enough time to check them all.)
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  #99 (permalink)  
Old 17-January-2005, 11:57 AM
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Now there's only one "classical" moon of Saturn, Hyperion, that lacks better-than-Voyager images by Cassini. Hopefully it'll take some good views of the small satellites too.
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  #100 (permalink)  
Old 17-January-2005, 01:14 PM
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Cassini Picture of the Day: Rhea and Her Craters



Somehow this view looks dull compared to the new photos. :-?
Well, distance does matter.
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  #101 (permalink)  
Old 17-January-2005, 06:31 PM
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Race of the Moons



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This movie, showing six of Saturn's small ring-region moons as they raced around the planet, was made from images taken by the Cassini spacecraft on Nov. 15, 2004.
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  #102 (permalink)  
Old 17-January-2005, 09:37 PM
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Am I the only one who noticed the extremely prolate shape of Mimas?
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  #103 (permalink)  
Old 17-January-2005, 09:48 PM
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Quote:
Originally Posted by Kullat Nunu
Now there's only one "classical" moon of Saturn, Hyperion, that lacks better-than-Voyager images by Cassini. Hopefully it'll take some good views of the small satellites too.
Hyperion looks like it's shaped more like a space station than a moon. Can't wait for a closeup.

It really looks more like a rock though from Voyager.
http://www.solarviews.com/eng/hyperion.htm
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  #104 (permalink)  
Old 17-January-2005, 10:07 PM
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Quote:
Originally Posted by Kullat Nunu
Now there's only one "classical" moon of Saturn, Hyperion, that lacks better-than-Voyager images by Cassini. Hopefully it'll take some good views of the small satellites too.
According to my notes, Cassini will come within 615 miles of Hyperion on September 26th of this year.
=D>
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  #105 (permalink)  
Old 18-January-2005, 07:09 AM
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Cassini raw images have been updated again; actual high-resolution Rhea pictures are available here (files N00026654.jpg to N00026682.jpg).
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  #106 (permalink)  
Old 18-January-2005, 07:39 AM
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Quote:
Originally Posted by Kullat Nunu
Cassini raw images have been updated again; actual high-resolution Rhea pictures are available here (files N00026654.jpg to N00026682.jpg).
The new images of Enceladus are what really caught my eye:

http://saturn1.jpl.nasa.gov/multimed.../N00026570.jpg

I'm really looking forward to the close flyby on February 17.

--Chris
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  #107 (permalink)  
Old 18-January-2005, 07:53 AM
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Originally Posted by quaternion
I'm really looking forward to the close flyby on February 17.
I hear ya.

That's a great picture.
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  #108 (permalink)  
Old 18-January-2005, 08:15 AM
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Quote:
Originally Posted by quaternion
Quote:
Originally Posted by Kullat Nunu
Cassini raw images have been updated again; actual high-resolution Rhea pictures are available here (files N00026654.jpg to N00026682.jpg).
The new images of Enceladus are what really caught my eye:

http://saturn1.jpl.nasa.gov/multimed.../N00026570.jpg

I'm really looking forward to the close flyby on February 17.

--Chris
Oh wow!
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  #109 (permalink)  
Old 18-January-2005, 04:30 PM
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Mimas below the rings:



And yes, the_shaggy_one, Mimas looks very prolate in these images.
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  #110 (permalink)  
Old 19-January-2005, 11:24 PM
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Cassini, Zooming In on Enceladus

The fun continues
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