A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Sunday, September 6, 1998,[1] with an umbral magnitude of −0.1544. 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 1.8 days before perigee (on September 8, 1998, at 7:00 UTC), the Moon's apparent diameter was larger.[2]
Visibility
The eclipse was completely visible over northeast Asia, much of Australia, western North America and the Pacific Ocean, seen rising over east and southeast Asia and western Australia and setting over much of North and South America.[3]
 
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Eclipse details
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 0.81217 |
| Umbral Magnitude | −0.15437 |
| Gamma | −1.10579 |
| Sun Right Ascension | 10h59m47.2s |
| Sun Declination | +06°25'26.3" |
| Sun Semi-Diameter | 15'52.1" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 23h01m06.1s |
| Moon Declination | -07°29'07.2" |
| Moon Semi-Diameter | 16'25.0" |
| Moon Equatorial Horizontal Parallax | 1°00'15.2" |
| ΔT | 63.3 s |
Eclipse season
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. The first and last eclipse in this sequence is separated by one synodic month.
| August 8 Descending node (full moon) |
August 22 Ascending node (new moon) |
September 6 Descending node (full moon) |
|---|---|---|
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| Penumbral lunar eclipse Lunar Saros 109 |
Annular solar eclipse Solar Saros 135 |
Penumbral lunar eclipse Lunar Saros 147 |
Related eclipses
Eclipses in 1998
- A total solar eclipse on February 26.
- A penumbral lunar eclipse on March 13.
- A penumbral lunar eclipse on August 8.
- An annular solar eclipse on August 22.
- A penumbral lunar eclipse on September 6.
Metonic
- Preceded by: Lunar eclipse of November 18, 1994
- Followed by: Lunar eclipse of June 24, 2002
Tzolkinex
- Preceded by: Lunar eclipse of July 26, 1991
- Followed by: Lunar eclipse of October 17, 2005
Half-Saros
- Preceded by: Solar eclipse of August 31, 1989
- Followed by: Solar eclipse of September 11, 2007
Tritos
- Preceded by: Lunar eclipse of October 7, 1987
- Followed by: Lunar eclipse of August 6, 2009
Lunar Saros 147
- Preceded by: Lunar eclipse of August 26, 1980
- Followed by: Lunar eclipse of September 16, 2016
Inex
- Preceded by: Lunar eclipse of September 25, 1969
- Followed by: Lunar eclipse of August 17, 2027
Triad
- Preceded by: Lunar eclipse of November 6, 1911
- Followed by: Lunar eclipse of July 7, 2085
Lunar eclipses of 1995–1998
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 8, 1998 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1995 to 1998 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||||
| Saros | Date Viewing |
Type Chart |
Gamma | Saros | Date Viewing |
Type Chart |
Gamma | |
| 112 | 1995 Apr 15
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Partial
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−0.9594 | 117 | 1995 Oct 08
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Penumbral
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1.1179 | |
122
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1996 Apr 04
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Total
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−0.2534 | 127
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1996 Sep 27
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Total
|
0.3426 | |
132
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1997 Mar 24
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Partial
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0.4899 | 137 | 1997 Sep 16
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Total
|
−0.3768 | |
| 142 | 1998 Mar 13
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Penumbral
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1.1964 | 147 | 1998 Sep 06
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Penumbral
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−1.1058 | |
Saros 147
This eclipse is a part of Saros series 147, repeating every 18 years, 11 days, and containing 70 events. The series started with a penumbral lunar eclipse on July 2, 1890. It contains partial eclipses from September 28, 2034 through May 27, 2431; total eclipses from June 6, 2449 through October 5, 2647; and a second set of partial eclipses from October 16, 2665 through May 1, 2990. The series ends at member 70 as a penumbral eclipse on July 28, 3145.
The longest duration of totality will be produced by member 37 at 105 minutes, 18 seconds on August 1, 2539. All eclipses in this series occur at the Moon’s descending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on 2539 Aug 01, lasting 105 minutes, 18 seconds.[7] | Penumbral | Partial | Total | Central |
| 1890 Jul 02 |
2034 Sep 28
|
2449 Jun 06 |
2485 Jun 28 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2593 Sep 02 |
2647 Oct 05 |
2990 May 01 |
3134 Jul 28 | |
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.
| Series members 1–18 occur between 1890 and 2200: | |||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | |||
| 1890 Jul 02 | 1908 Jul 13 | 1926 Jul 25 | |||
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| 4 | 5 | 6 | |||
| 1944 Aug 04 | 1962 Aug 15 | 1980 Aug 26 | |||
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| 7 | 8 | 9 | |||
| 1998 Sep 06 | 2016 Sep 16 | 2034 Sep 28 | |||
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| 10 | 11 | 12 | |||
| 2052 Oct 08 | 2070 Oct 19 | 2088 Oct 30 | |||
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| 13 | 14 | 15 | |||
| 2106 Nov 11 | 2124 Nov 21 | 2142 Dec 03 | |||
| 16 | 17 | 18 | |||
| 2160 Dec 13 | 2178 Dec 24 | 2197 Jan 04 | |||
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 2096 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1802 Mar 19 (Saros 129) |
1813 Feb 15 (Saros 130) |
1824 Jan 16 (Saros 131) |
1834 Dec 16 (Saros 132) |
1845 Nov 14 (Saros 133) | |||||
| 1856 Oct 13 (Saros 134) |
1867 Sep 14 (Saros 135) |
1878 Aug 13 (Saros 136) |
1889 Jul 12 (Saros 137) |
1900 Jun 13 (Saros 138) | |||||
| 1911 May 13 (Saros 139) |
1922 Apr 11 (Saros 140) |
1933 Mar 12 (Saros 141) |
1944 Feb 09 (Saros 142) |
1955 Jan 08 (Saros 143) | |||||
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| 1965 Dec 08 (Saros 144) |
1976 Nov 06 (Saros 145) |
1987 Oct 07 (Saros 146) |
1998 Sep 06 (Saros 147) |
2009 Aug 06 (Saros 148) | |||||
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| 2020 Jul 05 (Saros 149) |
2031 Jun 05 (Saros 150) |
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| 2096 Nov 29 (Saros 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).[8] This lunar eclipse is related to two partial solar eclipses of Solar Saros 154.
| August 31, 1989 | September 11, 2007 |
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See also
References
- ^ "September 6, 1998 Penumbral Lunar Eclipse". timeanddate. Retrieved 9 January 2025.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 9 January 2025.
- ^ "Penumbral Lunar Eclipse of 1998 Sep 06" (PDF). NASA. Retrieved 9 January 2025.
- ^ "Penumbral Lunar Eclipse of 1998 Sep 06". EclipseWise.com. Retrieved 9 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.
- ^ "NASA - Catalog of Lunar Eclipses of Saros 147". eclipse.gsfc.nasa.gov.
- ^ Listing of Eclipses of series 147
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
- Saros cycle 147
- 1998 Sep 06 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
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