Planetshine

The phenomenon known as planetshine occurs when reflected sunlight from a planet illuminates the night side of one of its moons. Typically, this results in the moon's night side being bathed in a soft, faint light. The best known example of planetshine is earthshine, which can be seen from Earth when the Moon is a thin crescent. Planetshine has been observed elsewhere in the solar system: in particular, it has recently been used by the Cassini space probe to image portions of the moons of Saturn even when they are not lit by the Sun.


Diagram of planetshine

Read more about Planetshine:  Earthshine, Ringshine, Search For Terrestrial Planets