For the record, I don't think there's anything extraterrestrial/supernatural/otherwise "spooky" about Iapetus, but since we're talking about
elements from fiction finding a place in the real world...
In the book version of Arthur C. Clarke's "2001", the Discovery goes to Saturn, not Jupiter, and orbits Iapetus. Iapetus has (as Clarke knew at
the time) one hemisphere that is brighter than the other. In the middle of this hemisphere, Clarke wrote, Dave Bowman sees a single black spot - the
monolith made famous by the movie.
When
Voyager II flew past Saturn in 1981 (13 years after "2001" was published), the probe sent
back a picture of the moon's bright hemisphere with - you guessed it - a black spot in the middle of a field of white.
In an introduction to "2010", the sequel to "2001", Clarke wrote that Carl Sagan, a member of the Voyger Imaging Team, sent him a copy of the
photo. On the photo Sagan wrote "Thinking of you..."
[edit on 17-10-2006 by PhloydPhan]