TWO TOTAL LUNAR ECLIPSES

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Equally fascinating, however, is the fact that the sunlight would never reach the lunar surface if it traveled in a straight line (and was blocked by the earth). Instead, the wavelengths are refracted (bent) by our atmosphere and focused into the earthly umbra.

THE TOUCH OF TOTALITY
Finally, the climax of the eclipse approaches. The midpoint of totality in the morning hours of July 6 will occur at 3:31 a.m. EDT. As the sphere passes through the center—or darkest part—of the umbra, viewers can expect to see a completely altered satellite, ranging in color from orange copper to rose to deep blood red.

The moon's position in the umbra is not the only factor determining its hue during eclipse, though. Also contributing is the weather along the area of earth experiencing dawn or dusk as the eclipse progresses . . . since that twilight is projected, through our planet's atmosphere, directly onto the lunar surface. Therefore, eclipses that occur when that ring of earth is especially cloudy will be darker than normal . . . and can be remarkably so if, for example, the upper atmosphere happens to be full of volcanic ash from a recent eruption.

Neither of the 1982 lunar eclipses is expected to be exceptionally dark . . . but each one will surely display a dazzling array of hues during its course (the longer July event promises to be especially spectacular). Furthermore, lunar eclipses typically proceed slowly enough to allow an artist or photographer to record the changes in detail. And the colorful happenings are worth preserving. Besides the various shades of red common to such events, other hues—including sea green and gold—are frequently seen on the lunar face. And a particular weather disturbance, such as a large storm front, in a twilight region of earth will often cause a spot of special color to appear on the eclipsed moon.

When the total phase of the July 6 eclipse finally draws to a close (at 4:24 a.m. EDT, when hints of dawn will be appearing along the East Coast), the sequence will begin to reverse: Partial eclipse (stage three), as the moon moves out of the umbra, proceeds until the orb's west (right) edge is free of the shadow's dark stain. For viewers in the eastern states, that won't take place until almost sunrise . . . but people watching on the West Coast will be able to see this partial phase end while the moon is still well above the horizon in a dark sky.

From that point on, our satellite will be moving through the penumbra, and the "fringe" shadow should last be visible on the lunar face around 4:00 a.m. Mountain Daylight Time. Finally, the moon will completely leave the penumbral region at 4:40 a.m. MDT, signaling the end of the eclipse.

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