The annular eclipse of 10 May 1994 is the fifty-seventh member of Saros series 128, as defined by van den Bergh (1955). All eclipses in the series occur at the Moon's descending node and gamma increases with each member in the series. The family began on 29 Aug 984 with a partial eclipse in the southern hemisphere. During the next four centuries, a total of twenty-four partial eclipses occurred with the eclipse magnitude of each succeeding event gradually increasing. Finally, the first umbral eclipse occurred on 16 May 1417. The event was a total eclipse of short duration which was followed by three more eclipses with similar characteristics. The twenty-ninth event occurred on 28 Jun 1489 and was of annular/total nature. The ensuing three members were also annular/total eclipses of monotonically decreasing duration. This was a direct consequence of the Moon's increasing distance with each event. Eventually, the character of the series changed to pure annular with the thirty-third member on 11 Aug 1561.
For almost three centuries, Saros 128 continued to produce annular eclipses where each event was of progressively smaller magnitude and increasing duration. The trend culminated with the annular eclipses of 1 Feb 1832 and 12 Feb 1850, each of which was characterized by an eclipse magnitude of 0.934 and a greatest duration of 8m 35s. Having reached its orbital apogee, the Moon's distance began to decrease with each succeeding eclipse, resulting in annular eclipses of increasing magnitude and decreasing duration. Although the annular eclipse of 10 May 1994 still reaches a magnitude of 0.943 and a maximum duration of 6 minutes 14 seconds, each subsequent event is of rapidly diminishing maximum duration. To illustrate, the eclipses of 20 May 2012, 1 Jun 2030 and 11 Jun 2048 will exhibit maximum durations of 5m 46s, 5m 21s and 4m 58s respectively as the path of each event shifts northward. Member sixty-four is the last central eclipse of the series and occurs on 15 Jul 2120. The remaining nine events are partial in the northern hemisphere with the last and seventy-third member occurring on 1 Nov 2282.
In summary, Saros series 128 includes 73 eclipses with the following distribution:
Partial Annular Ann/Tota Total ------- ------- -------- ----- Non-Central 33 0 0 0 Central -- 32 4 4