January 1973 lunar eclipse
| Penumbral eclipse | |||||||||
The Moon's hourly motion shown right to left | |||||||||
| Date | January 18, 1973 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.0845 | ||||||||
| Magnitude | −0.1292 | ||||||||
| Saros cycle | 143 (16 of 73) | ||||||||
| Penumbral | 236 minutes, 29 seconds | ||||||||
| |||||||||
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Thursday, January 18, 1973, with an umbral magnitude of −0.1292. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into 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 2 days after perigee (on January 16, 1973, at 20:50 UTC), the Moon's apparent diameter was larger.
This eclipse was the first of four lunar eclipses in 1973, with the others occurring on June 15 (penumbral), July 15 (penumbral), and December 10 (partial).