Skip to comments.Astronomy Picture of the Day -- Saturn's Iapetus: Painted Moon
Posted on 01/13/2012 5:55:13 PM PST by SunkenCiv
Explanation: What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as ice. The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon. Iapetus also has an unusual equatorial ridge that makes it appear like a walnut. To help better understand this seemingly painted moon, NASA directed the robotic Cassini spacecraft orbiting Saturn to swoop within 2,000 kilometers in 2007. Pictured above, from about 75,000 kilometers out, Cassini's trajectory allowed unprecedented imaging of the hemisphere of Iapetus that is always trailing. A huge impact crater seen in the south spans a tremendous 450 kilometers and appears superposed on an older crater of similar size. The dark material is seen increasingly coating the easternmost part of Iapetus, darkening craters and highlands alike. Close inspection indicates that the dark coating typically faces the moon's equator and is less than a meter thick. A leading hypothesis is that the dark material is mostly dirt leftover when relatively warm but dirty ice sublimates. An initial coating of dark material may have been effectively painted on by the accretion of meteor-liberated debris from other moons. This and other images from Cassini's Iapetus flyby are being studied for even greater clues.
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Wow! That’s a rough looking place!
Looks like that thing has had the hell beaten out of it over time. Some massive craters(to put it mildly) there.
A really, really good block party.
Great pic, btw, thanks. ;)
Burned out Death Star.
The above pic is from 2007, and is also found here:
[snip] Iapetus has a diameter of 1,471 km (914 miles) and a density only 1.2 times that of liquid water. It has been suggested that Iapetus (like Rhea) is three quarters ice and one quarter rock. [/snip]
Voyager pics from 1981 show the icy surface as quite shiny, e.g.:
and an animation made from all eight 1981 V pics:
A huge impact crater seen in the south spans a tremendous 450 kilometers and appears superposed on an older crater of similar size.
This is going to sadden many of you, And I expect that.
Richard Hoagland has some good stuff on this moon. There are a LOT of mysterious, seemingly impossible features on this body. Check out http://www.enterprisemission.com/moon1.htm
I know, I know... Richard Hoagland. I happen to appreciate his style and his findings.
It looks like is was casted.
Hoaxland’s claims about Iapetus’ artificiality are themselves entirely imaginary, so it’s appropriate that he borrows so heavily from sci-fi writer Art Clarke.
Looks like it was attacked by the Death Star, and lived.... lol
:’) If only Voyager had arrived *before* Star Wars...
this too was drolly amusing:
Think Tank: The Economics of Death Star Planet Destruction
S##ew Hoaxland and what he claims ... There is still the Cassini photos showing the unusual shape and the equatoral ridge. Nothing natural we know of scienticifally about planet/moon formation explains those features.
Thanks for all the links, Civ.