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September 1977 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Tuesday, September 27, 1977,[1] with an umbral magnitude of −0.1361. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into 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 about 6.25 days before apogee (on October 3, 1977, at 14:45 UTC), the Moon's apparent diameter was smaller.[2] VisibilityThe eclipse was completely visible over North America, northwestern South America, and the central and eastern Pacific Ocean, seen rising over east and northeast Asia and Australia and setting over much of South America and the Atlantic Ocean.[3]
Eclipse detailsShown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
Eclipse seasonThis 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 eclipsesEclipses in 1977
Metonic
Tzolkinex
Half-Saros
Tritos
Lunar Saros 117
Inex
Triad
Lunar eclipses of 1977–1980This 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.[5] The penumbral lunar eclipse on July 27, 1980 occurs in the next lunar year eclipse set.
Saros 117This eclipse is a part of Saros series 117, repeating every 18 years, 11 days, and containing 71 events. The series started with a penumbral lunar eclipse on April 3, 1094. It contains partial eclipses from June 29, 1238 through September 23, 1382; total eclipses from October 3, 1400 through June 21, 1815; and a second set of partial eclipses from July 2, 1833 through September 5, 1941. The series ends at member 71 as a penumbral eclipse on May 15, 2356. The longest duration of totality was produced by member 35 at 105 minutes, 43 seconds on April 17, 1707. All eclipses in this series occur at the Moon’s descending node of orbit.[6]
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 seriesThis 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.
Half-Saros cycleA lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[8] This lunar eclipse is related to two solar eclipses of Solar Saros 124.
See alsoNotes
External links
Information related to September 1977 lunar eclipse |
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