M a g i c a l S a r o s

Here is the Way that Christopher Columbus tricked the Native Indians on the island of Hispanola (what is now Dominican Republic and Haiti), into not killing him, in fact they made him a God. He had been circling the Island with the Band of 100,00 Indians following from the shore line, this was his third voyage to the new world, and he had a reputation, as they were widely know all over the Caribbean. Then they came to the site of Playa de Blanca on the North Shore of the Island where Columbus knew at precisely what time a Solar Eclipse would happen blackening the Sun for 7 Minutes. When he did land, he told the approaching Indians to stand off or he would turn off the Sun. They Laughed, when the eclipse came they held him in reverence and he eventually conquered the Island and was appointed the Governor by the King of Spain. Sadly, during the next decade, due to Disease and the Inquisition the population of this Largest Island in the Caribbean went from 500,000 to 50,000.

moon

earth

Period Names	Period Description		Period Times	Period #/Saros
Lunation Period	The Moon travels around the Earth. Every 29.530589 days, full moon to full moon.		29 days 12 hours 44 minutes 2.4seconds	223/saros
Draconian Period	The Moon twice crosses the equatorial plane every 27.212220 days, the 'moon runs high', the 'moon runs low'.		27 days 5 hours 5 minutes 34 seconds	242/saros
Ananomalistic Period	The Moon also oscillates between being near and far, (apogee and perigee) with a cycle of 27.5545770151 days.		27 days 13 hours 18 minutes 36 seconds	239/saros

Ready for the next Amazing Thing?

Multiple the period length by the
number of periods in the saros cycle :
1. 29.530589 x 223 = 6585.321347
2. 27.212220 x 242 = 6585.357240
3. 27.554577 x 239 = 6585.543903
  1. or 18 years 15 days 8 hours
Note : the amazingly small difference, only minutes over 18 years

So as it works out these seemingly independent phenomena recur every 18 years 15 days 8 hours plus .222557 hrs or 13.35 minutes this being the error between the widest repeated periods. This plus the 8 hours is meaningless with respects to the Lunar eclipse, as they are seen over half the earth, but introduces the factor of your position on the earth with respects to the solar eclipse. Note, also that a 18 year period can have 4 or 5 Leap years, hence we may well subtract 1 or 2 days from the time passage.

This is not to say that we would only expect an eclipse every 18 years , because actually there are at any one time between 50 and 70 cycles of saros going on. Each cycle having 70 to 90 observer events and then decaying, becoming just another full or new moon as are more than 7/8 ths of all lunar orbits. Lunar eclipses recur 48 or 49 times and solar eclipses 68 to 75 times before slight error, as above, eliminate the eclipse from the cycle. During one SAROS cycles about 70 eclipses, (some 1260 years), of the solar, usually 10 are total and 31 partial and 29 are lunar. The minimum number of eclipses that can occur in a given year is 2, the maximum 7, and the average is 4. All of course from differing saros cycles. During the 20th century 375 eclipses have taken place: 228 solar and 147 lunar.

You can see I hope, that what so ever was the relative position of the Sun Moon and Earth, will repeat at the interval called the Saros.

The Moon travels around the Earth and the Earth-Moon System travels around the Sun, Every 365.242199 days, or; 365 days 5 hours 48 minutes 45.97 seconds in each of what we call a year, and it has no significance to this. I though it was worth mentioning.

Kids MATH
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