Solar eclipse of October 12, 1977


A total solar eclipse occurred at the Moon's ascending node of orbit on Wednesday, October 12, 1977, with a magnitude of 1.0269. 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 2.6 days before perigee, the Moon's apparent diameter was larger.
Totality was visible in the Pacific Ocean, Colombia and Venezuela. A partial eclipse was visible for parts of North America, Central America, the Caribbean, and northern South America.

Observations

The National Geographic Society funded an expedition by sea led by Jay Pasachoff from Williams College, Massachusetts to the northeast Pacific Ocean to observe the total eclipse. The team took images of the sky and corona during the totality phase as well as corona spectrum and infrared images.

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.
EventTime
First Penumbral External Contact1977 October 12 at 17:48:24.0 UTC
First Umbral External Contact1977 October 12 at 18:48:59.6 UTC
First Central Line1977 October 12 at 18:49:18.4 UTC
First Umbral Internal Contact1977 October 12 at 18:49:37.3 UTC
First Penumbral Internal Contact1977 October 12 at 20:01:41.4 UTC
Equatorial Conjunction1977 October 12 at 20:15:17.1 UTC
Greatest Eclipse1977 October 12 at 20:27:27.3 UTC
Greatest Duration1977 October 12 at 20:30:55.5 UTC
Ecliptic Conjunction1977 October 12 at 20:31:29.7 UTC
Last Penumbral Internal Contact1977 October 12 at 20:53:33.8 UTC
Last Umbral Internal Contact1977 October 12 at 22:05:23.4 UTC
Last Central Line1977 October 12 at 22:05:44.5 UTC
Last Umbral External Contact1977 October 12 at 22:06:05.6 UTC
Last Penumbral External Contact1977 October 12 at 23:06:31.5 UTC

ParameterValue
Eclipse Magnitude1.02694
Eclipse Obscuration1.05462
Gamma0.38363
Sun Right Ascension13h11m36.7s
Sun Declination-07°35'30.0"
Sun Semi-Diameter16'01.8"
Sun Equatorial Horizontal Parallax08.8"
Moon Right Ascension13h12m03.0s
Moon Declination-07°13'40.8"
Moon Semi-Diameter16'12.7"
Moon Equatorial Horizontal Parallax0°59'29.8"
ΔT48.3 s

Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months 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.
September 27
Descending node
October 12
Ascending node
Penumbral lunar eclipse
Lunar Saros 117		Total solar eclipse
Solar Saros 143

Related eclipses

Eclipses in 1977

Metonic

Tzolkinex

Half-Saros

Tritos

Solar Saros 143

Inex

Triad