Todays Astronomy Picture of the Day is Iapetus, one of the moons of Saturn:
Each of the major moons of the solar system is unique. Iapetus is interesting for the great contrast between its brilliant white surface, which is probably composed of water ice, and the dark black area on the right, which could be covered by some form of carbon.
In the novel 2001: A Space Odyssey, Iapetus is the site of the transformation of astronaut Dave Bowman into the “star child.” In the film, this occurs in orbit around Jupiter rather than inside Iapetus.
Grace and Peace