A total lunar eclipse occurred at the Moon’s ascending node of orbit on Thursday, August 17, 1989,[1] with an umbral magnitude of 1.5984. It was a central lunar eclipse, in which part of the Moon passed through the center of the Earth's shadow. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. 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. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 2.4 days before perigee (on August 19, 1989, at 13:30 UTC), the Moon's apparent diameter was larger.[2]

Visibility

The eclipse was completely visible over eastern North America, South America, west Africa, and Antarctica, seen rising over western and central North America and the eastern Pacific Ocean and setting over Europe, much of Africa, and west, central, and south Asia.[3]


The Moon's hourly motion across the Earth's shadow in the constellation of Capricornus.

Eclipse details

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

August 17, 1989 Lunar Eclipse Parameters
Parameter Value
Penumbral Magnitude 2.57033
Umbral Magnitude 1.59838
Gamma −0.14905
Sun Right Ascension 09h46m02.0s
Sun Declination +13°27'24.4"
Sun Semi-Diameter 15'47.9"
Sun Equatorial Horizontal Parallax 08.7"
Moon Right Ascension 21h46m17.4s
Moon Declination -13°35'27.7"
Moon Semi-Diameter 16'15.3"
Moon Equatorial Horizontal Parallax 0°59'39.3"
ΔT 56.6 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 August 1989
August 17
Ascending node (full moon)
 August 31
Descending node (new moon)
Total lunar eclipse
Lunar Saros 128		 Partial solar eclipse
Solar Saros 154

Eclipses in 1989

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 128

Inex

Triad

Lunar eclipses of 1988–1991

This eclipse is the second of four lunar year eclipses occurring at the Moon's ascending node.

The lunar year series repeats after 12 lunations or 354 days (Shifting back about 10 days in sequential years). Because of the date shift, the Earth's shadow will be about 11 degrees west in sequential events.

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 lunar eclipses on June 27, 1991 (penumbral) and December 21, 1991 (partial) occur in the next lunar year eclipse set.

Lunar eclipse series sets from 1988 to 1991
Descending node   Ascending node
Saros Date
Viewing 		Type
Chart 		Gamma Saros Date
Viewing 		Type
Chart 		Gamma
113 1988 Mar 03
 Penumbral
 0.9886 118 1988 Aug 27
 Partial
 −0.8682
123 1989 Feb 20
 Total
0.2935 128 1989 Aug 17
 Total
 −0.1491
133 1990 Feb 09
 Total
 −0.4148 138 1990 Aug 06
 Partial
 0.6374
143 1991 Jan 30
 Penumbral
 −1.0752 148 1991 Jul 26
 Penumbral
 1.4370

Metonic series

It is the third of five Metonic cycle eclipses, each being separated by 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 in nearly the same location relative to the background stars.

Metonic lunar eclipse sets 1951–2027
Descending node   Ascending node
Saros Date Type Saros Date Type
103 1951 Feb 21.88 Penumbral 108 1951 Aug 17.13 Penumbral
113 1970 Feb 21.35 Partial 118 1970 Aug 17.14 Partial
123 1989 Feb 20.64 Total 128 1989 Aug 17.13 Total
133 2008 Feb 21.14 Total 138 2008 Aug 16.88 Partial
143 2027 Feb 20.96 Penumbral 148 2027 Aug 17.30 Penumbral

Saros 128

This eclipse is a part of Saros series 128, repeating every 18 years, 11 days, and containing 71 events. The series started with a penumbral lunar eclipse on June 18, 1304. It contains partial eclipses from September 2, 1430 through May 11, 1827; total eclipses from May 21, 1845 through October 21, 2097; and a second set of partial eclipses from November 2, 2115 through May 17, 2440. The series ends at member 71 as a penumbral eclipse on August 2, 2566.

The longest duration of totality was produced by member 37 at 100 minutes, 43 seconds on July 26, 1953. All eclipses in this series occur at the Moon’s ascending node of orbit.[6]

Greatest First

The greatest eclipse of the series occurred on 1953 Jul 26, lasting 100 minutes, 43 seconds.[7] 		Penumbral Partial Total Central
1304 Jun 18
 1430 Sep 02
 1845 May 21
 1899 Jun 23
Last
Central Total Partial Penumbral
2007 Aug 28
 2097 Oct 21
 2440 May 17
 2566 Aug 02

Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.

Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.

Series members between 1801 and 2200
1804 Jan 26
(Saros 111) 		1814 Dec 26
(Saros 112) 		1825 Nov 25
(Saros 113) 		1836 Oct 24
(Saros 114) 		1847 Sep 24
(Saros 115)
1858 Aug 24
(Saros 116) 		1869 Jul 23
(Saros 117) 		1880 Jun 22
(Saros 118) 		1891 May 23
(Saros 119) 		1902 Apr 22
(Saros 120)
1913 Mar 22
(Saros 121) 		1924 Feb 20
(Saros 122) 		1935 Jan 19
(Saros 123) 		1945 Dec 19
(Saros 124) 		1956 Nov 18
(Saros 125)
1967 Oct 18
(Saros 126) 		1978 Sep 16
(Saros 127) 		1989 Aug 17
(Saros 128) 		2000 Jul 16
(Saros 129) 		2011 Jun 15
(Saros 130)
2022 May 16
(Saros 131) 		2033 Apr 14
(Saros 132) 		2044 Mar 13
(Saros 133) 		2055 Feb 11
(Saros 134) 		2066 Jan 11
(Saros 135)
2076 Dec 10
(Saros 136) 		2087 Nov 10
(Saros 137) 		2098 Oct 10
(Saros 138) 		2109 Sep 09
(Saros 139) 		2120 Aug 09
(Saros 140)
2131 Jul 10
(Saros 141) 		2142 Jun 08
(Saros 142) 		2153 May 08
(Saros 143) 		2164 Apr 07
(Saros 144) 		2175 Mar 07
(Saros 145)
2186 Feb 04
(Saros 146) 		2197 Jan 04
(Saros 147)

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[8] This lunar eclipse is related to two annular solar eclipses of Solar Saros 135.

August 10, 1980 August 22, 1998

See also

Notes

  1. ^ "August 16–17, 1989 Total Lunar Eclipse (Blood Moon)". timeanddate. Retrieved 7 January 2025.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 7 January 2025.
  3. ^ "Total Lunar Eclipse of 1989 Aug 17" (PDF). NASA. Retrieved 7 January 2025.
  4. ^ "Total Lunar Eclipse of 1989 Aug 17". EclipseWise.com. Retrieved 7 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. ^ "NASA - Catalog of Lunar Eclipses of Saros 128". eclipse.gsfc.nasa.gov.
  7. ^ Listing of Eclipses of series 128
  8. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
Allikas: https://en.wikipedia.org/wiki/August_1989_lunar_eclipse
No tags for this post.