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 (on October 15, 1977, at 10:00 UTC), 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.
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.
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.
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.