Danjon scale
The Danjon Scale is a way to rate the brightness of a lunar eclipse. It's named after André Louis Danjon, a French astronomer who developed a system to compare the brightness of different lunar eclipses. The scale has five levels, and each level tells us how bright the eclipse is.
Level 0 is the darkest level. This means the moon is not visible during a lunar eclipse.
Level 1 means that the moon is very dark during the eclipse.
Level 2 means that the moon is still dark, but it's not as dark as Level 1.
Level 3 means that the moon is brighter than Levels 1 and 2, but still not very bright.
Level 4 means that the moon is the brightest level of all. This means that the eclipse is very bright and you can see it clearly.
Level 0 is the darkest level. This means the moon is not visible during a lunar eclipse.
Level 1 means that the moon is very dark during the eclipse.
Level 2 means that the moon is still dark, but it's not as dark as Level 1.
Level 3 means that the moon is brighter than Levels 1 and 2, but still not very bright.
Level 4 means that the moon is the brightest level of all. This means that the eclipse is very bright and you can see it clearly.