Solar eclipses of 1968–1971 edit

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.^[1]

Saros 129 edit

It is a part of Saros cycle 129, repeating every 18 years, 11 days, containing 80 events. The series started with partial solar eclipse on October 3, 1103. It contains annular eclipses on May 6, 1464 through March 18, 1969, hybrid eclipses from March 29, 1987 through April 20, 2023 and total eclipses from April 30, 2041 through July 26, 2185. The series ends at member 80 as a partial eclipse on February 21, 2528. The longest duration of totality was 3 minutes, 43 seconds on June 25, 2131 . All eclipses in this series occurs at the Moon’s ascending node.^[2]

Tritos series edit

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.

Metonic series edit

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 ascending node.

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