Solar eclipse of May 20, 1966


An annular solar eclipse occurred at the Moon's ascending node of orbit on Friday, May 20, 1966, with a magnitude of 0.9991. 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus. An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. The Moon's apparent diameter was near the average diameter because it occurred 6.8 days after apogee and 7.2 days before perigee.
Annularity was visible from Guinea, Mali, Algeria, Libya, Greece, Turkey, the Soviet Union and China. A partial eclipse was visible for parts of North Africa, Central Africa, Northeast Africa, Europe, West Asia, Central Asia, North Asia, and South Asia.

Observations

During this eclipse, the apex of the moon's umbral cone was very close to the Earth's surface, and the magnitude was very large. The edges of the moon and the sun were very close to each other as seen from the Earth. Baily's beads on the lunar limb, which are usually only visible during a total solar eclipse, could also be seen. Therefore this eclipse was also an excellent opportunity to measure the size and shape of the Earth, as well as the mountains and valleys on the lunar limb. Many scientists observed the annular eclipse in Greece and Turkey, which are close to the location of maximum eclipse and have better observation conditions. The observation sites in Greece were mainly concentrated in Saronida and Anavyssos south of Athens, while those in Turkey were mainly concentrated in Ayvalik, across the sea facing the Greek island Lesbos.
Similar to the Baily's beads, the corona is generally only visible in a total solar eclipse. Because the magnitude of this annular eclipse was close to 1, some predicted that the corona would be visible. An observation team went to Lesbos Island but only saw the Baily's beads, not the corona.
Prior to it, the two hybrid solar eclipses of April 17, 1912 and April 28, 1930, and another annular solar eclipse of May 9, 1948 also belonging to Solar Saros 137, also occurred with a magnitude close to 1. Observations were made near Paris in France, Camptonville, California and Rebun Island in Japan respectively.

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 Contact1966 May 20 at 06:50:51.2 UTC
First Umbral External Contact1966 May 20 at 07:54:07.8 UTC
First Central Line1966 May 20 at 07:54:41.4 UTC
Greatest Duration1966 May 20 at 07:54:41.4 UTC
First Umbral Internal Contact1966 May 20 at 07:55:14.9 UTC
First Penumbral Internal Contact1966 May 20 at 09:07:24.3 UTC
Greatest Eclipse1966 May 20 at 09:39:01.6 UTC
Ecliptic Conjunction1966 May 20 at 09:42:51.0 UTC
Equatorial Conjunction1966 May 20 at 09:51:45.8 UTC
Last Penumbral Internal Contact1966 May 20 at 10:10:21.8 UTC
Last Umbral Internal Contact1966 May 20 at 11:22:42.3 UTC
Last Central Line1966 May 20 at 11:23:12.9 UTC
Last Umbral External Contact1966 May 20 at 11:23:43.5 UTC
Last Penumbral External Contact1966 May 20 at 12:27:00.2 UTC

ParameterValue
Eclipse Magnitude0.99915
Eclipse Obscuration0.99830
Gamma0.34672
Sun Right Ascension03h46m47.1s
Sun Declination+19°55'23.3"
Sun Semi-Diameter15'48.2"
Sun Equatorial Horizontal Parallax08.7"
Moon Right Ascension03h46m20.7s
Moon Declination+20°14'08.1"
Moon Semi-Diameter15'33.4"
Moon Equatorial Horizontal Parallax0°57'05.7"
ΔT36.9 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.
May 4
Descending node
May 20
Ascending node
Penumbral lunar eclipse
Lunar Saros 111		Annular solar eclipse
Solar Saros 137

Related eclipses

Eclipses in 1966

Metonic

Tzolkinex

Half-Saros

Tritos

Solar Saros 137

Inex

Triad