Explanation: What causes the bright streaks on Dione?
Recent and likely future images of this unusual moon by the robot Cassini spacecraft now orbiting Saturn might help us find out.
The above image was taken at the end of October from a distance of about one million kilometers.
The bright streaks run across some of Dione's many craters, indicating that the process that created them occurred later than the impacts that created those craters.
Dione is made of mostly water ice but its relatively high density indicates that it contains much rock inside.
