Danjon scale

Quick Reference

A scale for roughly estimating the darkness of a total lunar eclipse, originated by A. Danjon. The five-point scale runs from 0 (extremely dark, Moon invisible) to 4 (extremely bright, eclipse having little effect on Moon's visibility). The darkness of a lunar eclipse is largely determined by the opacity of the Earth's atmosphere, which is affected by clouds and volcanic dust.

Subjects: Astronomy and Astrophysics.

Reference entries