Solar eclipse of April 7, 1978

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.^[2]

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.

• A total lunar eclipse on March 24.
• A partial solar eclipse on April 7.
• A total lunar eclipse on September 16.
• A partial solar eclipse on October 2.

• Preceded by: Solar eclipse of June 20, 1974
• Followed by: Solar eclipse of January 25, 1982

• Preceded by: Solar eclipse of February 25, 1971
• Followed by: Solar eclipse of May 19, 1985

• Preceded by: Lunar eclipse of April 2, 1969
• Followed by: Lunar eclipse of April 14, 1987

• Preceded by: Solar eclipse of May 9, 1967
• Followed by: Solar eclipse of March 7, 1989

• Preceded by: Solar eclipse of March 27, 1960
• Followed by: Solar eclipse of April 17, 1996

• Preceded by: Solar eclipse of April 28, 1949
• Followed by: Solar eclipse of March 19, 2007

• Preceded by: Solar eclipse of June 6, 1891
• Followed by: Solar eclipse of February 5, 2065

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.^[3]

This eclipse is a part of Saros series 148, repeating every 18 years, 11 days, and containing 75 events. The series started with a partial solar eclipse on September 21, 1653. It contains annular eclipses on April 29, 2014 and May 9, 2032; a hybrid eclipse on May 20, 2050; and total eclipses from May 31, 2068 through August 3, 2771. The series ends at member 75 as a partial eclipse on December 12, 2987. 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 annularity will be produced by member 22 at 22 seconds (by default) on May 9, 2032, and the longest duration of totality will be produced by member 54 at 5 minutes, 23 seconds on April 26, 2609. All eclipses in this series occur at the Moon’s descending node of orbit.^[4]

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.

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.

• Earth visibility chart and eclipse statistics Eclipse Predictions by Fred Espenak, NASA/GSFC
  • Google interactive map
  • Besselian elements