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Mystery of Saturn's Two-Faced Moon Solved
TheChemist
post Oct 9 2007, 02:31 PM
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Carolyn Porco comments included in this space.com article :

http://www.space.com/scienceastronomy/0710...ni-iapetus.html
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ngunn
post Oct 15 2007, 09:07 AM
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Since disconnected dark patches have formed on the 'green' trailing side too you clearly don't require the 'red' stuff to start one off. Something else must have started them. So if you invoke the 'red' stuff as the trigger on the leading side you have to postulate a completely separate triggering process for the other hemisphere. Occam doesn't like that either. There may well be a reddish dusting on one hemisphere (or a 'green' one on the other, or the red/green difference may be due to a selective removal process rather than deposition - I haven't a clue) but I don't think this is what triggered the runaway blackhouse. Since the red/green dichotomy appears to overlie frosted areas too it must be much more recent than most of the sublimation.
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- TheChemist   Mystery of Saturn's Two-Faced Moon Solved   Oct 9 2007, 02:31 PM
- - alan   Some press releases from the Cassini site, the lin...   Oct 9 2007, 02:54 PM
- - Greg Hullender   In that case, why only Iapetus? Why don't we ...   Oct 9 2007, 03:24 PM
|- - ElkGroveDan   QUOTE (Greg Hullender @ Oct 9 2007, 07:24...   Oct 9 2007, 03:29 PM
|- - ngunn   QUOTE (Greg Hullender @ Oct 9 2007, 04:24...   Oct 9 2007, 03:57 PM
|- - JRehling   QUOTE (Greg Hullender @ Oct 9 2007, 08:24...   Oct 9 2007, 03:57 PM
|- - AscendingNode   QUOTE (Greg Hullender @ Oct 9 2007, 08:24...   Oct 9 2007, 04:09 PM
- - tasp   And, Hyperion and Iapetus are the only two major s...   Oct 10 2007, 05:06 AM
- - ngunn   I've no problem with the feedback process, or ...   Oct 10 2007, 08:36 AM
- - tasp   The 'seeding' material for the darkening p...   Oct 11 2007, 03:51 AM
- - David   Iapetus doesn't need a huge differentiation in...   Oct 11 2007, 07:42 AM
|- - ngunn   QUOTE (David @ Oct 11 2007, 08:42 AM) But...   Oct 11 2007, 08:03 AM
- - Greg Hullender   Thinking about this some more, this comment ...   Oct 11 2007, 04:51 PM
|- - ugordan   QUOTE (Greg Hullender @ Oct 11 2007, 06:5...   Oct 11 2007, 04:56 PM
|- - stevesliva   QUOTE (Greg Hullender @ Oct 11 2007, 12:5...   Oct 12 2007, 03:04 AM
- - alan   The dust is theorized to have originated from a ou...   Oct 11 2007, 05:03 PM
- - nprev   Considering Titan as a potential source, I almost ...   Oct 11 2007, 05:22 PM
- - Greg Hullender   Alan, ugordon: Thanks. I suppose I should have sa...   Oct 11 2007, 09:18 PM
- - alan   Its the leading hemisphere because the dust is mov...   Oct 12 2007, 02:51 AM
|- - ElkGroveDan   QUOTE (alan @ Oct 11 2007, 06:51 PM) Here...   Oct 15 2007, 02:25 AM
- - Greg Hullender   steve: Good catch. Thanks! Given, then, that...   Oct 12 2007, 05:00 PM
- - Bill Harris   QUOTE Could material spalled off from Phoebe accou...   Oct 13 2007, 02:46 AM
- - elakdawalla   If I recall correctly, Phoebe has long been consid...   Oct 13 2007, 03:54 AM
|- - ugordan   That's correct. Of all the significant moons o...   Oct 13 2007, 05:06 PM
- - ngunn   Why is everyone so sure about this global dusting ...   Oct 13 2007, 07:05 PM
|- - ugordan   The fact remains the leading and trailing hemisphe...   Oct 13 2007, 08:29 PM
- - tasp   Salient inferrence there, ugordan. Curious a spa...   Oct 13 2007, 08:59 PM
- - nprev   Fascinating ideas and discussion. Crap; I knew th...   Oct 15 2007, 02:52 AM
- - ngunn   Since disconnected dark patches have formed on the...   Oct 15 2007, 09:07 AM

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