Saturn’s moon Dione, photographed by Cassini, 29 January 2011.
What’s going on with the lighting here?  Dione appears to be a crescent with the light hitting only a small part of the bottom of the moon as seen from the camera, but much of the top half is also bathed in light.  The streaky stars in the background suggest that these photos are each of quite long exposure, so I suspect that the very bright lower crescent is reflected sunlight, and the moderately bright upper crescent is reflected Saturnshine.

Saturn’s moon Dione, photographed by Cassini, 29 January 2011.

What’s going on with the lighting here?  Dione appears to be a crescent with the light hitting only a small part of the bottom of the moon as seen from the camera, but much of the top half is also bathed in light.  The streaky stars in the background suggest that these photos are each of quite long exposure, so I suspect that the very bright lower crescent is reflected sunlight, and the moderately bright upper crescent is reflected Saturnshine.