# October 1968 lunar eclipse

A total lunar eclipse occurred at the Moon’s ascending node of orbit on Sunday, October 6, 1968, with an umbral magnitude of 1.1691. 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 5.3 days before apogee (on October 11, 1968, at 18:05 UTC), the Moon's apparent diameter was smaller.
This lunar eclipse was the last of a tetrad, with four total lunar eclipses in series, the others being on April 24, 1967; October 18, 1967; and April 13, 1968.

## Visibility

The eclipse was completely visible over northeast Asia, eastern Australia, northwestern North America and much of the Pacific Ocean, seen rising over most of Asia and western Australia and setting over North and South America.

## Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
October 6, 1968 Lunar Eclipse Parameters :
| Parameter | Value |
| Penumbral Magnitude | 2.22423 |
| Umbral Magnitude | 1.16913 |
| Gamma | 0.36054 |
| Sun Right Ascension | 12h48m51.9s |
| Sun Declination | -05°14'36.0" |
| Sun Semi-Diameter | 16'00.2" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 00h48m13.3s |
| Moon Declination | +05°32'13.0" |
| Moon Semi-Diameter | 15'10.1" |
| Moon Equatorial Horizontal Parallax | 0°55'39.9" |
| ΔT | 39.0 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.
Eclipse season of September–October 1968 :
| September 22 Descending node (new moon) | October 6 Ascending node (full moon) |
| Total solar eclipse Solar Saros 124 | Total lunar eclipse Lunar Saros 136 |

## Related eclipses
### Eclipses in 1968

* A partial solar eclipse on March 28.
* A total lunar eclipse on April 13.
* A total solar eclipse on September 22.
* A total lunar eclipse on October 6.

### Metonic

* Preceded by: Lunar eclipse of December 19, 1964
* Followed by: Lunar eclipse of July 26, 1972

### Tzolkinex

* Preceded by: Lunar eclipse of August 26, 1961
* Followed by: Lunar eclipse of November 18, 1975

### Half-Saros

* Preceded by: Solar eclipse of October 2, 1959
* Followed by: Solar eclipse of October 12, 1977

### Tritos

* Preceded by: Lunar eclipse of November 7, 1957
* Followed by: Lunar eclipse of September 6, 1979

### Lunar Saros 136

* Preceded by: Lunar eclipse of September 26, 1950
* Followed by: Lunar eclipse of October 17, 1986

### Inex

* Preceded by: Lunar eclipse of October 28, 1939
* Followed by: Lunar eclipse of September 16, 1997

### Triad

* Preceded by: Lunar eclipse of December 5, 1881
* Followed by: Lunar eclipse of August 7, 2055

### 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.
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 | Descending node | Descending node | Descending node | Ascending node | Ascending node | Ascending 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 |

### Saros 136

This eclipse is a part of Saros series 136, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on April 13, 1680. It contains partial eclipses from July 11, 1824 through September 14, 1932; total eclipses from September 26, 1950 through July 7, 2419; and a second set of partial eclipses from July 18, 2437 through October 3, 2563. The series ends at member 72 as a penumbral eclipse on June 1, 2960.
The longest duration of totality will be produced by member 35 at 101 minutes, 23 seconds on April 21, 2293. All eclipses in this series occur at the Moon’s ascending node of orbit.
| Greatest | First | First | First | First |
| The greatest eclipse of the series will occur on 2293 Apr 21, lasting 101 minutes, 23 seconds. | Penumbral | Partial | Total | Central |
| The greatest eclipse of the series will occur on 2293 Apr 21, lasting 101 minutes, 23 seconds. | 1680 Apr 13 | 1824 Jul 11 | 1950 Sep 26 | 2022 Nov 08 |
| Last ||||
| The greatest eclipse of the series will occur on 2293 Apr 21, lasting 101 minutes, 23 seconds. | Central | Total | Partial | Penumbral |
| The greatest eclipse of the series will occur on 2293 Apr 21, lasting 101 minutes, 23 seconds. | 2365 Jun 04 | 2419 Jul 07 | 2563 Oct 03 | 2960 Jun 01 |
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 8–29 occur between 1801 and 2200: :
| 8 | 8 | 9 | 9 | 10 | 10 |
| 1806 Jun 30 | 1806 Jun 30 | 1824 Jul 11 | 1824 Jul 11 | 1842 Jul 22 | 1842 Jul 22 |
| 11 | 11 | 12 | 12 | 13 | 13 |
| 1860 Aug 01 | 1860 Aug 01 | 1878 Aug 13 | 1878 Aug 13 | 1896 Aug 23 | 1896 Aug 23 |
| 14 | 14 | 15 | 15 | 16 | 16 |
| 1914 Sep 04 | 1914 Sep 04 | 1932 Sep 14 | 1932 Sep 14 | 1950 Sep 26 | 1950 Sep 26 |
| 17 | 17 | 18 | 18 | 19 | 19 |
| 1968 Oct 06 | 1968 Oct 06 | 1986 Oct 17 | 1986 Oct 17 | 2004 Oct 28 | 2004 Oct 28 |
| 20 | 20 | 21 | 21 | 22 | 22 |
| 2022 Nov 08 | 2022 Nov 08 | 2040 Nov 18 | 2040 Nov 18 | 2058 Nov 30 | 2058 Nov 30 |
| 23 | 23 | 24 | 24 | 25 | 25 |
| 2076 Dec 10 | 2076 Dec 10 | 2094 Dec 21 | 2094 Dec 21 | 2113 Jan 02 | 2113 Jan 02 |
| 26 | 26 | 27 | 27 | 28 | 28 |
| 2131 Jan 13 | 2131 Jan 13 | 2149 Jan 23 | 2149 Jan 23 | 2167 Feb 04 | 2167 Feb 04 |
| 29 ||
| 2185 Feb 14 ||

### 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 2187 :
| 1805 Jan 15 (Saros 121) | 1805 Jan 15 (Saros 121) | 1815 Dec 16 (Saros 122) | 1815 Dec 16 (Saros 122) | 1826 Nov 14 (Saros 123) | 1826 Nov 14 (Saros 123) | 1837 Oct 13 (Saros 124) | 1837 Oct 13 (Saros 124) | 1848 Sep 13 (Saros 125) | 1848 Sep 13 (Saros 125) |
| 1859 Aug 13 (Saros 126) | 1859 Aug 13 (Saros 126) | 1870 Jul 12 (Saros 127) | 1870 Jul 12 (Saros 127) | 1881 Jun 12 (Saros 128) | 1881 Jun 12 (Saros 128) | 1892 May 11 (Saros 129) | 1892 May 11 (Saros 129) | 1903 Apr 12 (Saros 130) | 1903 Apr 12 (Saros 130) |
| 1914 Mar 12 (Saros 131) | 1914 Mar 12 (Saros 131) | 1925 Feb 08 (Saros 132) | 1925 Feb 08 (Saros 132) | 1936 Jan 08 (Saros 133) | 1936 Jan 08 (Saros 133) | 1946 Dec 08 (Saros 134) | 1946 Dec 08 (Saros 134) | 1957 Nov 07 (Saros 135) | 1957 Nov 07 (Saros 135) |
| 1968 Oct 06 (Saros 136) | 1968 Oct 06 (Saros 136) | 1979 Sep 06 (Saros 137) | 1979 Sep 06 (Saros 137) | 1990 Aug 06 (Saros 138) | 1990 Aug 06 (Saros 138) | 2001 Jul 05 (Saros 139) | 2001 Jul 05 (Saros 139) | 2012 Jun 04 (Saros 140) | 2012 Jun 04 (Saros 140) |
| 2023 May 05 (Saros 141) | 2023 May 05 (Saros 141) | 2034 Apr 03 (Saros 142) | 2034 Apr 03 (Saros 142) | 2045 Mar 03 (Saros 143) | 2045 Mar 03 (Saros 143) | 2056 Feb 01 (Saros 144) | 2056 Feb 01 (Saros 144) | 2066 Dec 31 (Saros 145) | 2066 Dec 31 (Saros 145) |
| 2077 Nov 29 (Saros 146) | 2077 Nov 29 (Saros 146) | 2088 Oct 30 (Saros 147) | 2088 Oct 30 (Saros 147) | 2099 Sep 29 (Saros 148) | 2099 Sep 29 (Saros 148) | 2110 Aug 29 (Saros 149) | 2110 Aug 29 (Saros 149) | 2121 Jul 30 (Saros 150) | 2121 Jul 30 (Saros 150) |
| 2132 Jun 28 (Saros 151) | 2132 Jun 28 (Saros 151) | 2143 May 28 (Saros 152) | 2143 May 28 (Saros 152) | 2154 Apr 28 (Saros 153) | 2154 Apr 28 (Saros 153) | | | | |
| 2187 Jan 24 (Saros 156) ||

### Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2200 :
| 1824 Jan 16 (Saros 131) | 1824 Jan 16 (Saros 131) | 1852 Dec 26 (Saros 132) | 1852 Dec 26 (Saros 132) | 1881 Dec 05 (Saros 133) | 1881 Dec 05 (Saros 133) |
| 1910 Nov 17 (Saros 134) | 1910 Nov 17 (Saros 134) | 1939 Oct 28 (Saros 135) | 1939 Oct 28 (Saros 135) | 1968 Oct 06 (Saros 136) | 1968 Oct 06 (Saros 136) |
| 1997 Sep 16 (Saros 137) | 1997 Sep 16 (Saros 137) | 2026 Aug 28 (Saros 138) | 2026 Aug 28 (Saros 138) | 2055 Aug 07 (Saros 139) | 2055 Aug 07 (Saros 139) |
| 2084 Jul 17 (Saros 140) | 2084 Jul 17 (Saros 140) | 2113 Jun 29 (Saros 141) | 2113 Jun 29 (Saros 141) | 2142 Jun 08 (Saros 142) | 2142 Jun 08 (Saros 142) |
| 2171 May 19 (Saros 143) | 2171 May 19 (Saros 143) | 2200 Apr 30 (Saros 144) | 2200 Apr 30 (Saros 144) |

### Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse is related to two total solar eclipses of Solar Saros 143.
| October 2, 1959 | October 12, 1977 |