A Saros is a cycle of eclipses.
One Saros period of 6585.3211 days. It has two variants of reaching that total-
*14 years + 4 leap years + 11.321 days or
*13 years + 5 leap years + 10.321 days
Unless you are a super geek- which you probably are because you are reading this- the why of the duration of a Saros Cycle of eclipses is what it is so just accept the truth and move on, we are not here to argue why pi does not have peaches and a mole has no hair. http://www.eclipsewise.com
These cycles of similar eclipse events are grouped into separate Saros that have overlapping periods. Generally the cycles begin with partial, evolve to hybrid, climax with total then devolve back to partial before the end of a roughly 12-15 century cycle. The 2017 event will be only the 22nd of 76 or 77 in this cycle. As this Saros Cycle matures so does the duration of eclipse totality with the longest duration of 7 min 12 sec due to arrive on June 25th 2522. The first total eclipse of Saros 145 was June 29, 1917 with a duration of only 50 seconds. There are currently 40 different Saros Cycles operating(117-156). The last solar eclipse view able from the contiguous US was 1979, the 59th of 71 in Saros 120. Saros 120
The first acknowledged recording of Saros appears to be used by neo-Babylonian astronomers and later by the likes of Pliny and Ptolemy. The actual coining of the phrase is most often attributed to Sir Edmund Hillary. 120 of the 222 month cycles makes for 2222 years. Unable to find a scientific name for this value in time I will seize the opportunity to one up the legendary Sir and heretofore refer to it as a Schwafinitum. Carbondale, IL Eclipse Crossroads
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