Sun Dog
A sun dog is a bright, often coloured patch of light appearing about 22 degrees or more to the left or right of the sun, caused by ice crystals in the air.
Full definition of Sun Dog →:: COMPARE ::
Sun dogvsSun pillar
The short answer
Both come from the same falling plate crystals, but by different physics. A sun dog is refraction — light bends THROUGH the crystal, so it splits into colours at 22 degrees. A sun pillar is reflection — light bounces OFF the flat faces, so it stays white and forms a vertical shaft.
Side by side
| Aspect | Sun dog | Sun pillar |
|---|---|---|
| Physics | Refraction | Reflection |
| Colour | Dispersed | White |
| Shape | Patch at 22° | Vertical shaft |
| Same crystals | Yes | Yes |
What each one means
Sun pillar
The contrast above sets out how Sun pillar differs from Sun Dog on the points that actually matter.