Alternative definitions (0), class: vernacular (0)
Term: Penumbra

The portion of a shadow in which light from an extended source is partially but not completely cut off by an intervening body; the area of partial shadow surrounding the umbra. The lighter part of a shadow during an eclipse. An observer standing in the penumbra of a Solar eclipse will see a partial eclipse.

Created 2023.04.16
Last Modified 2023.04.16
Contributed by Ryan McGranaghan