STAGE 4

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With three-quarters of the Moon's disk now eclipsed, that part of it that is immersed in shadow should begin to very faintly light up, similar to a piece of iron heated to the point where it just begins to glow. It now becomes obvious that the umbral shadow is not complete darkness.

Using binoculars or a telescope, the shadow's outer part is usually light enough to reveal lunar seas and craters, but the central part is much darker, and sometimes no surface features are recognizable. Colors in the umbra vary greatly from one eclipse to the next, Reds and grays usually predominate, but sometimes browns, blues and other tints are seen.

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