December 1991 lunar eclipse

The moon passes west to east (right to left) across northern edge of the Earth's umbral shadow, shown in hourly intervals.

A partial lunar eclipse took place on Saturday, December 21, 1991, the last of four lunar eclipses in 1991. The moon grazed the northern edge of the umbral shadow. It occurred near perigee, and as described, such event was known as a supermoon.

Visibility

This small partial eclipse was visible from North America, eastern Asia, Australia, and western South America.

Eclipses of 1991

Lunar year series

Lunar eclipse series sets from 1991–1994
Ascending node   Descending node
Saros Date
Viewing
Type
Chart
Gamma Saros Date
Viewing
Type
Chart
Gamma
110 1991 Jun 27
Penumbral
−1.40641 115 1991 Dec 21
Partial
0.97094
120 1992 Jun 15
Partial
−0.62887 125
1992 Dec 9
Total
0.31438
130 1993 Jun 4
Total
0.16376 135
1993 Nov 29
Total
−0.39941
140 1994 May 25
Partial
0.89334 145 1994 Nov 18
Penumbral
−1.10479
Last set 1991 Jul 26 Last set 1991 Jan 30
Next set 1995 Apr 15 Next set 1995 Oct 08

Metonic cycles (19 years)

The Metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the Earth's shadow will be in nearly the same location relative to the background stars.

Ascending node Descending node
  1. 1991 Jun 27 - penumbral (110)
  2. 2010 Jun 26 - partial (120)
  3. 2029 Jun 26 - total (130)
  4. 2048 Jun 26 - partial (140)
  5. 2067 Jun 27 - penumbral (150)
  1. 1991 Dec 21 - partial (115)
  2. 2010 Dec 21 - total (125)
  3. 2029 Dec 20 - total (135)
  4. 2048 Dec 20 - partial (145)

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[1] This lunar eclipse is related to two partial solar eclipses of Solar Saros 122.

December 15, 1982 December 25, 2000

See also

References

  1. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros