A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Wednesday, October 7, 1987,[1] with an umbral magnitude of −0.0095. 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 3.1 days after perigee (on October 4, 1987, at 1:35 UTC), the Moon's apparent diameter was larger.[2]
| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | October 7, 1987 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | 1.0189 | ||||||||
| Magnitude | −0.0095 | ||||||||
| Saros cycle | 146 (9 of 72) | ||||||||
| Penumbral | 253 minutes, 28 seconds | ||||||||
| |||||||||
Visibility
editThe eclipse was completely visible over much of North America, South America, west Africa, and western Europe, seen rising over northwestern North America and the central Pacific Ocean and setting over much of Africa, Europe, and west and central Asia.[3]
|
Eclipse details
editShown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 0.98640 |
| Umbral Magnitude | −0.00949 |
| Gamma | 1.01890 |
| Sun Right Ascension | 12h49m09.5s |
| Sun Declination | -05°16'24.7" |
| Sun Semi-Diameter | 16'00.1" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 00h47m14.4s |
| Moon Declination | +06°09'13.6" |
| Moon Semi-Diameter | 16'04.0" |
| Moon Equatorial Horizontal Parallax | 0°58'58.1" |
| ΔT | 55.6 s |
Eclipse season
editThis 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.
| September 23 Descending node (new moon) |
October 7 Ascending node (full moon) |
|---|---|
 |
|
| Annular solar eclipse Solar Saros 134 |
Penumbral lunar eclipse Lunar Saros 146 |
Related eclipses
editEclipses in 1987
edit- A hybrid solar eclipse on March 29.
- A penumbral lunar eclipse on April 14.
- An annular solar eclipse on September 23.
- A penumbral lunar eclipse on October 7.
Metonic
edit- Preceded by: Lunar eclipse of December 20, 1983
- Followed by: Lunar eclipse of July 26, 1991
Tzolkinex
edit- Preceded by: Lunar eclipse of August 26, 1980
- Followed by: Lunar eclipse of November 18, 1994
Half-Saros
edit- Preceded by: Solar eclipse of October 2, 1978
- Followed by: Solar eclipse of October 12, 1996
Tritos
edit- Preceded by: Lunar eclipse of November 6, 1976
- Followed by: Lunar eclipse of September 6, 1998
Lunar Saros 146
edit- Preceded by: Lunar eclipse of September 25, 1969
- Followed by: Lunar eclipse of October 17, 2005
Inex
edit- Preceded by: Lunar eclipse of October 27, 1958
- Followed by: Lunar eclipse of September 16, 2016
Triad
edit- Preceded by: Lunar eclipse of December 6, 1900
- Followed by: Lunar eclipse of August 7, 2074
Lunar eclipses of 1984–1987
editThis 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 June 13, 1984 occurs in the previous lunar year eclipse set.
| Lunar eclipse series sets from 1984 to 1987 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||||
| Saros | Date Viewing |
Type Chart |
Gamma | Saros | Date Viewing |
Type Chart |
Gamma | |
| 111 | 1984 May 15
|
Penumbral
|
1.1131 | 116 | 1984 Nov 08
|
Penumbral
|
−1.0900 | |
| 121 | 1985 May 04
|
Total
|
0.3520 | 126 | 1985 Oct 28
|
Total
|
−0.4022 | |
| 131 | 1986 Apr 24
|
Total
|
−0.3683 | 136 | 1986 Oct 17
|
Total
|
0.3189 | |
| 141 | 1987 Apr 14
|
Penumbral
|
−1.1364 | 146 | 1987 Oct 07
|
Penumbral
|
1.0189 | |
Half-Saros cycle
editA 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 partial solar eclipses of Solar Saros 153.
| October 2, 1978 | October 12, 1996 |
|---|---|
|
|
See also
editNotes
edit- ^ "October 6–7, 1987 Penumbral Lunar Eclipse". timeanddate. Retrieved 6 January 2025.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 6 January 2025.
- ^ "Penumbral Lunar Eclipse of 1987 Oct 07" (PDF). NASA. Retrieved 6 January 2025.
- ^ "Penumbral Lunar Eclipse of 1987 Oct 07". EclipseWise.com. Retrieved 6 January 2025.
- ^ 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.
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
edit- 1987 Oct 07 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
 | This lunar eclipse-related article is a stub. You can help Wikipedia by expanding it. |