Saturn's two-faced moon
The moon with the split personality, Iapetus, presents a puzzling appearance. One hemisphere of the moon is very dark, while the other is very bright.
Whether the moon is being coated by foreign material or being resurfaced by material from within is not yet known. The brightness variations in this image are not due to shadowing, they are real.
Its diameter is about one third that of our own Moon at 1436 kilometres.
The Cassini-Huygens mission is a co-operative project of NASA, ESA and ASI, the Italian space agency.
Credits: NASA/JPL/Space Science Institute