| Penumbral eclipse | |||||||||
| Date | 20 January 1981 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.0141 | ||||||||
| Magnitude | 1.0136 | ||||||||
| Saros cycle | 114 (57 of 71) | ||||||||
| Penumbral | 263 minutes, 50 seconds | ||||||||
| |||||||||
A penumbral lunar eclipse took place on Tuesday, January 20, 1981, the first of two lunar eclipses in 1981. In a rare total penumbral eclipse, the entire Moon was partially shaded by the Earth (though none of it was in complete shadow), and the shading across the Moon should have been quite visible at maximum eclipse. The penumbral phase lasted for 4 hours and 24 minutes in all, though for most of it, the eclipse was extremely difficult, if not impossible to see. The moon's apparent diameter was larger because the eclipse occurred 5.2 days after perigee (Perigee on approximately 1981 Jan 15 at 03:01:56.7 UTC).[1]
This was a relatively rare total penumbral lunar eclipse with the moon passing entirely within the penumbral shadow without entering the darker umbral shadow.[2]