October 1966 lunar eclipse

October 1966 lunar eclipse
Penumbral eclipse
The Moon's hourly motion shown right to left
DateOctober 29, 1966
Gamma−1.0600
Magnitude−0.1249
Saros cycle116 (55 of 73)
Penumbral273 minutes, 41 seconds
Contacts (UTC)
P17:55:27
Greatest10:12:16
P412:29:08

A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Saturday, October 29, 1966,[1] with an umbral magnitude of −0.1249. 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 4 days after apogee (on October 25, 1966, at 9:55 UTC), the Moon's apparent diameter was smaller.[2]

Visibility

The eclipse was completely visible over northeast Asia, much of North America, and the Pacific Ocean, seen rising over east and southeast Asia and Australia and setting over eastern North America and South America.[3]

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]

October 29, 1966 Lunar Eclipse Parameters
Parameter Value
Penumbral Magnitude 0.95172
Umbral Magnitude −0.12488
Gamma −1.05999
Sun Right Ascension 14h12m57.7s
Sun Declination -13°22'20.9"
Sun Semi-Diameter 16'06.2"
Sun Equatorial Horizontal Parallax 08.9"
Moon Right Ascension 02h14m38.8s
Moon Declination +12°29'37.7"
Moon Semi-Diameter 14'57.5"
Moon Equatorial Horizontal Parallax 0°54'53.8"
ΔT 37.2 s

Eclipse season

See also: Eclipse cycle

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.

Eclipse season of October–November 1966
October 29
Ascending node (full moon)
 November 12
Descending node (new moon)
Penumbral lunar eclipse
Lunar Saros 116		 Total solar eclipse
Solar Saros 142

Eclipses in 1966

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 116

Inex

Triad

Lunar eclipses of 1966–1969

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[5]

The penumbral lunar eclipse on August 27, 1969 occurs in the next lunar year eclipse set.

Lunar eclipse series sets from 1966 to 1969
Descending node   Ascending node
Saros Date
Viewing 		Type
Chart 		Gamma Saros Date
Viewing 		Type
Chart 		Gamma
111 1966 May 04
 Penumbral
 1.0554 116 1966 Oct 29
 Penumbral
 −1.0600
121 1967 Apr 24
 Total
 0.2972 126 1967 Oct 18
 Total
 −0.3653
131 1968 Apr 13
 Total
 −0.4173 136 1968 Oct 06
 Total
 0.3605
141 1969 Apr 02
 Penumbral
 −1.1765 146 1969 Sep 25
 Penumbral
 1.0656

Metonic series

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 in nearly the same location relative to the background stars.

Metonic events: May 4 and October 28
Descending node Ascending node
  1. 1966 May 4 - Penumbral (111)
  2. 1985 May 4 - Total (121)
  3. 2004 May 4 - Total (131)
  4. 2023 May 5 - Penumbral (141)
  1. 1966 Oct 29 - Penumbral (116)
  2. 1985 Oct 28 - Total (126)
  3. 2004 Oct 28 - Total (136)
  4. 2023 Oct 28 - Partial (146)
  5. 2042 Oct 28 - Penumbral (156)

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[6] This lunar eclipse is related to two solar eclipses of Solar Saros 123.

October 23, 1957 November 3, 1975

See also

Notes

  1. ^ "October 28–29, 1966 Penumbral Lunar Eclipse". timeanddate. Retrieved 2 January 2025.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 2 January 2025.
  3. ^ "Penumbral Lunar Eclipse of 1966 Oct 29" (PDF). NASA. Retrieved 2 January 2025.
  4. ^ "Penumbral Lunar Eclipse of 1966 Oct 29". EclipseWise.com. Retrieved 2 January 2025.
  5. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  6. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros