The next eclipse of the moon will greet early risers before dawn on Friday morning (Nov. 19) across North America.
It will be the second lunar eclipse of 2021 and, in some ways, will be similar to the one back in May. Most North Americans will again need to get up early and look low in the west toward daybreak. And again, the farther west you are the better, as the moon will appear much higher from the western part of the continent as opposed to locations farther to the east. It will also be the longest duration eclipse in 580 years, lasting about 3 hours, 28 minutes and 23 seconds, and also the longest this century.
But in another way, it will be different. This lunar eclipse will fall just shy of being total; 97.4% of the moon’s diameter will become immersed in the Earth’s dark umbral shadow at maximum eclipse, leaving just the southernmost limb ever-so-slightly beyond the outer edge of the umbra.
To those watching with the naked eye, binoculars, and small telescopes, the lower edge of the moon will likely remain much brighter than the deep red or ochre hue we can expect across the rest of the moon’s face.
Because the moon will arrive at apogee — the farthest point in its orbit from Earth — on Nov. 20, it will also be moving at its slowest speed in its orbit. That’s why it will seem to move at an almost “leisurely pace” through the Earth’s shadow, taking over 100 minutes from the time of first umbral contact to the time of greatest eclipse, and vice versa (greatest eclipse to last umbral contact).