A total solar eclipse occurred at the Moon's descending node of orbit on Thursday, December 22, 1870, with a magnitude of 1.0248. 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. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 1.4 days before perigee (on December 21, 1870, at 3:50 UTC), the Moon's apparent diameter was larger.[1]
The path of totality was visible from parts of modern-day southern Portugal, southern Spain, northern Morocco, northern Algeria, Tunisia, Italy, Greece, northwestern Turkey, southeastern Bulgaria, southeastern Ukraine, and western Russia. A partial solar eclipse was also visible for parts of eastern Canada, Europe, North Africa, West Africa, and the Middle East.
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.[2]
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.
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.[3]
The partial solar eclipses on January 31, 1870 and July 28, 1870 occurs in the previous lunar year eclipse set.
This eclipse is a part of Saros series 120, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on May 27, 933 AD. It contains annular eclipses from August 11, 1059 through April 26, 1492; hybrid eclipses from May 8, 1510 through June 8, 1564; and total eclipses from June 20, 1582 through March 30, 2033. The series ends at member 71 as a partial eclipse on July 7, 2195. 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 annularity was produced by member 11 at 6 minutes, 24 seconds on September 11, 1113, and the longest duration of totality was produced by member 60 at 2 minutes, 50 seconds on March 9, 1997. All eclipses in this series occur at the Moon’s descending node of orbit.[4]
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 descending node.
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.
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.
