Eclipse cycle
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An eclipse cycle is an interval after which the relative geometry of the Sun, Earth, and Moon repeats closely enough for similar eclipses to occur. These cycles arise because several lunar months and orbital periods are nearly commensurable.
For an eclipse to occur, a new or full moon must take place near one of the Moon's orbital nodes, where its orbit crosses the ecliptic. The Moon must also be at a suitable distance and alignment for the particular type of solar or lunar eclipse.
Different eclipse cycles emphasise different combinations of the synodic, draconic, and anomalistic months. Important examples include the Saros, Inex, Tritos, and Exeligmos cycles.
Eclipses in a single cycle are related but not identical because the underlying periods do not match perfectly. Successive events shift geographically and gradually change in duration, magnitude, and type.
Source details and credits
- Source / publisher: Wikipedia
- URL type: WWW
- Credits: Wikipedia
- URL: https://en.wikipedia.org/wiki/Eclipse_cycle