hi Andrew<br /><font color="yellow">I wonder if these Hydrocarbons are related to the dark hemisphere of Iapetus, or is<br />similar to the dark material on Phoebe? </font><br /><br />According to this
Lunar and Planetary Science abstract, while Iapetus and Phoebe show clear signs of being related,<br /> <font color="orange">Hyperion<br />is spectrally red at visible wavelengths, similar<br />to D-type asteroids, and has been compared with organic<br />material. We find that at FUV wavelengths, Hyperion<br />is not spectrally redder than the Iapetus dark<br />material, but does appear to have more water ice.<br />Even when we attempt to isolate a spectrum of Hyperion<br />dark material, the Hyperion dark material still<br />appears to have more water ice than the Iapetus dark<br />material – no other spectral variations are apparent.</font><br /><br />From an old
Harvard abstract<br /><font color="orange">Structures along the bright-dark boundary, visible in Voyager 2 images, are inconsistent with an eruptive origin for the dark material; this zone is probably the region of grazing impacts of dust spiraling from Phoebe and the dark material is probably a minor component of the ice-dominated surface concentrated in the upper regolith produced by Phoebe-dust bombardment.</font> <br /><br />btw, congrats on reaching "solar system" -- you've joined the <i>illuminati</i>! <img src="/images/icons/cool.gif" /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>