Solar eclipse of December 3, 1918

An annular solar eclipse occurred at the Moon's ascending node of orbit on Tuesday, December 3, 1918, with a magnitude of 0.9383. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring 4.3 days after apogee (on November 29, 1918, at 7:10 UTC), the Moon's apparent diameter was smaller.

Annularity was visible from Chile including the capital city Santiago, Argentina including capital Buenos Aires, southern Uruguay including capital Montevideo, northeastern tip of South West Africa (today's Namibia) and southwestern Portuguese Angola (today's Angola). Aconcagua, the highest mountain outside Asia, also lies in the path of annularity. A partial eclipse was visible for parts of South America, Antarctica, Southern Africa, and Central Africa.

Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the Moon's penumbra or umbra attains the specific parameter, and the second table describes various other 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 1918

• A total solar eclipse on June 8.
• A partial lunar eclipse on June 24.
• An annular solar eclipse on December 3.
• A penumbral lunar eclipse on December 17.

Metonic

• Preceded by: Solar eclipse of February 14, 1915
• Followed by: Solar eclipse of September 21, 1922

Tzolkinex

• Preceded by: Solar eclipse of October 22, 1911
• Followed by: Solar eclipse of January 14, 1926

Half-Saros

• Preceded by: Lunar eclipse of November 27, 1909
• Followed by: Lunar eclipse of December 8, 1927

Tritos

• Preceded by: Solar eclipse of January 3, 1908
• Followed by: Solar eclipse of November 1, 1929

Solar Saros 131

• Preceded by: Solar eclipse of November 22, 1900
• Followed by: Solar eclipse of December 13, 1936

Inex

• Preceded by: Solar eclipse of December 22, 1889
• Followed by: Solar eclipse of November 12, 1947

Triad

• Preceded by: Solar eclipse of February 1, 1832
• Followed by: Solar eclipse of October 3, 2005

Solar eclipses of 1916–1920

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.

The solar eclipses on February 3, 1916 (total), July 30, 1916 (annular), January 23, 1917 (partial), and July 19, 1917 (partial) occur in the previous lunar year eclipse set.

Saros 131

This eclipse is a part of Saros series 131, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on August 1, 1125. It contains total eclipses from March 27, 1522 through May 30, 1612; hybrid eclipses from June 10, 1630 through July 24, 1702; and annular eclipses from August 4, 1720 through June 18, 2243. The series ends at member 70 as a partial eclipse on September 2, 2369. Its 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.

The longest duration of totality was produced by member 28 at 58 seconds on May 30, 1612, and the longest duration of annularity was produced by member 50 at 7 minutes, 54 seconds on January 26, 2009. All eclipses in this series occur at the Moon’s ascending node of orbit.

Metonic series

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's ascending node.

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.

Notes

• Eclipse Predictions by Fred Espenak, NASA/GSFC