August 1961 lunar eclipse

A partial lunar eclipse occurred at the Moon’s descending node of orbit on Saturday, August 26, 1961, with an umbral magnitude of 0.9863. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A partial lunar eclipse occurs when one part of the Moon is in the Earth's umbra, while the other part is in 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 only about 7.5 hours after perigee (on August 25, 1961, at 19:40 UTC), the Moon's apparent diameter was larger.

This nearly total lunar eclipse of Lunar Saros 137 preceded the first total eclipse on September 6, 1979. It was also the largest partial lunar eclipse since October 28, 1939, making it the second largest partial lunar eclipse of the 20th century.

Visibility

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

Eclipse details

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

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.

Related eclipses

Eclipses in 1961

• A total solar eclipse on February 15.
• A partial lunar eclipse on March 2.
• An annular solar eclipse on August 11.
• A partial lunar eclipse on August 26.

Metonic

• Preceded by: Lunar eclipse of November 7, 1957
• Followed by: Lunar eclipse of June 14, 1965

Tzolkinex

• Preceded by: Lunar eclipse of July 16, 1954
• Followed by: Lunar eclipse of October 6, 1968

Half-Saros

• Preceded by: Solar eclipse of August 20, 1952
• Followed by: Solar eclipse of August 31, 1970

Tritos

• Preceded by: Lunar eclipse of September 26, 1950
• Followed by: Lunar eclipse of July 26, 1972

Lunar Saros 137

• Preceded by: Lunar eclipse of August 15, 1943
• Followed by: Lunar eclipse of September 6, 1979

Inex

• Preceded by: Lunar eclipse of September 14, 1932
• Followed by: Lunar eclipse of August 6, 1990

Triad

• Preceded by: Lunar eclipse of October 25, 1874
• Followed by: Lunar eclipse of June 26, 2048

Lunar eclipses of 1958–1962

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 lunar eclipses on May 3, 1958 (partial) and October 28, 1958 (penumbral) occur in the previous lunar year eclipse set, and the penumbral lunar eclipse on July 17, 1962 occurs in the next lunar year eclipse set.

Saros 137

This eclipse is a part of Saros series 137, repeating every 18 years, 11 days, and containing 78 events. The series started with a penumbral lunar eclipse on December 17, 1564. It contains partial eclipses from June 10, 1835 through August 26, 1961; total eclipses from September 6, 1979 through June 28, 2466; and a second set of partial eclipses from July 9, 2484 through September 12, 2592. The series ends at member 78 as a penumbral eclipse on April 20, 2953.

The longest duration of totality will be produced by member 44 at 99 minutes, 53 seconds on April 13, 2340. All eclipses in this series occur at the Moon’s descending node of orbit.

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.

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.

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 144.

See also

• List of lunar eclipses
• List of 20th-century lunar eclipses

Notes

External links

• Eclipse Predictions by Fred Espenak, NASA/GSFC