July 1981 lunar eclipse
| Partial eclipse | |||||||||||||
The Moon's hourly motion shown right to left | |||||||||||||
| Date | July 17, 1981 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gamma | 0.7045 | ||||||||||||
| Magnitude | 0.5486 | ||||||||||||
| Saros cycle | 119 (60 of 83) | ||||||||||||
| Partiality | 163 minutes, 13 seconds | ||||||||||||
| Penumbral | 319 minutes, 37 seconds | ||||||||||||
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A partial lunar eclipse occurred at the Moon’s descending node of orbit on Friday, July 17, 1981, with an umbral magnitude of 0.5486. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A partial lunar eclipse occurs when one part of the Moon is in the Earth's umbra, while the other part is in the Earth's penumbra. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. Occurring about 5.4 days after apogee (on July 11, 1981, at 18:35 UTC), the Moon's apparent diameter was smaller.