Saros History

The periodicity and recurrence of solar (and lunar) eclipses is governed by the Saros cycle, a period of approximately 6,585.3 days (18 years 11 days 8 hours). When two eclipses are separated by a period of one Saros, they share a very similar geometry. The eclipses occur at the same node with the Moon at nearly the same distance from Earth and at the same time of year. Thus, the Saros is useful for organizing eclipses into families or series. Each series typically lasts 12 to 13 centuries and contains 70 or more eclipses.

The total eclipse of 2002 December 04 is the twenty-second member of Saros series 142 (Table 19), as defined by van den Bergh [1955]. All eclipses in the series occur at the Moon's descending node and the Moon moves northward with each member in the family (i.e. - gamma increases). Saros 142 is a young series which began with a small partial eclipse at high southern latitudes on 1624 Apr 17. After seven partial eclipses each of increasing magnitude, the first umbral eclipse occurred on 1750 Jul 03. This unusual annular eclipse was non-central and had no southern limit as the northern edge of the Moon's antumbral shadow briefly grazed Earth in the South Pacific. One saros later, the eclipse of 1768 Jul 14 was a short hybrid eclipse just south of Australia. The next eclipse in the series (1786 Jul 25) began a long sequence of total eclipses. The maximum duration of totality was just under one minute and the path passed through South Africa.

Over the next two centuries, the duration of totality of each eclipse has gradually increased as the Moon moved closer to perigee with every succeeding event. However, during the twentieth century, the maximum duration has hovered near two minutes as Earth approaches perihelion. In the next century, the duration will continue to increase as the umbral shadow passes progressively closer to Earth's geocenter. The most recent eclipse of the series occurred on 1984 Nov 22. The umbral path ran through Papua New Guinea and the South Pacific. After 2002, the following member occurs on 2020 Dec 14. Its track stretches from the South Pacific, across South America and into the South Atlantic.

By the twenty-third century, Saros 142 will be producing total eclipses with maximum durations exceeding six minutes in the northern tropics. The longest eclipse of the series occurs on 2291 May 28 and will last 6 minutes 34 seconds. The path of each succeeding event swings further north and a six minute eclipse will be visible from much of the United States on 2345 Jun 30. The duration of totality steadily decreases as the eclipse paths run through higher northern latitudes. The last total eclipse occurs in northern Canada on 2543 Oct 29. Although the event is central and lasts over two minutes, the northern edge of the umbral shadow will miss Earth completely. Partial eclipses will be visible from the northern hemisphere for the next three centuries. Saros 142 reaches its conclusion with the partial eclipse of 2886 May 25. A detailed list of eclipses in Saros series 142 appears in Table 19. A more detailed list, including local circumstances at greatest eclipse, is available.

In summary, Saros series 142 includes 72 eclipses. It begins with 7 partials, followed by 1 annular, 1 hybrid, 43 total eclipses and finally ends with 20 more partials. The total duration of Saros 142 is 1280.1 years.

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