:: COMPARE ::
The short answer
Both are backscattered twilight red, and they're two halves of one scene. The Belt of Venus is the pink anti-twilight arch in the sky opposite the sun, sitting above the blue band of Earth's own shadow. Alpenglow is that same light landing on a mountain face.
Side by side
| Aspect | Alpenglow | Belt of Venus |
|---|---|---|
| Where | On a mountain | In the sky |
| Direction | Opposite the sun | Opposite the sun |
| Light source | Backscattered | Backscattered |
| Needs mountains | Yes | No |
What each one means
Alpenglow is the rosy or cherry-red glow on snow-covered mountains at sunrise or sunset. Strictly it means the indirect glow seen when the sun itself is already below the horizon; dictionaries also allow the looser sense of any reddish sunrise or sunset light on a summit.
Full definition of Alpenglow →The contrast above sets out how Belt of Venus differs from Alpenglow on the points that actually matter.