A total solar eclipse occurred at the Moon’s descending node of orbit on Monday, December 14, 2020,[1][2][3][4][5][6] with a magnitude of 1.0254. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's and the apparent path of the Sun and Moon intersect, blocking all direct sunlight and turning daylight into darkness; the Sun appears to be black with a halo around it. 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 1.8 days after perigee (on December 12, 2020, at 20:40 UTC), the Moon's apparent diameter was larger.[7]
Totality was visible from parts of southern Chile and Argentina. A partial eclipse was visible for parts of central and southern South America, Southern Africa, and Antarctica. A total solar eclipse crossed a similar region of the Earth about a year and a half earlier on July 2, 2019.
The ionospheric effects of the eclipse were expected to be monitored as part of the December 2020 Eclipse Festival of Frequency Measurement, a citizen science experiment organized through the Amateur Radio Science Citizen Investigation (HamSCI).[9] Also, a prediction was made for a group of ionospheric stations in South America, using a numerical model (SUPIM-INPE), of the ionospheric response to this event.[10]
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.[11]
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.[12]
This eclipse is a part of Saros series 142, repeating every 18 years, 11 days, and containing 72 events. The series started with a partial solar eclipse on April 17, 1624. It contains a hybrid eclipse on July 14, 1768, and total eclipses from July 25, 1786 through October 29, 2543. There are no annular eclipses in this set. The series ends at member 72 as a partial eclipse on June 5, 2904. 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 will be produced by member 38 at 6 minutes, 34 seconds on May 28, 2291. All eclipses in this series occur at the Moon’s descending node of orbit.[13]
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.
21 eclipse events between July 22, 1971 and July 22, 2047
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.