Saros means repetition. A saros cycle of repetition of eclipses was discovered by the Babylonians. Around the second millennium BC, Babylonian astronomers started keeping records of the positions of the Moon and planets. By about the 4th century BC, enough data was accumulated to see the repeatability of lunar eclipses. They found that lunar eclipses have a cycle of 18 years.
With this knowledge, they could then predict lunar eclipses.
a) 19 synodic periods of the Moon’s node = 19 x 346.62 days = 6585.78 solar days.
b) 223 Lunations = 223 x 29.53049 = 6585.32 solar days
c) 239 Anomalistic months = 239 x 27.57455 = 6585.54 solar days. The three periods are the same as a day. This period is called the SAROS period. It equals 18 years and 11 days ( or 10 days depending on the number of Leap years in the duration)
If the Moon is at Perigee at a Node and is a New Moon on a particular day, a total solar eclipse will occur.
After a Saros period, the Moon will again be in almost the same configuration, and the eclipse will be repeated. Any configuration of the Moon in its orbit concerning the Sun, the Earth, and nodes perigee will be repeated after a Saros period. Of course, because the period is not in integral numbers. The time of day and the place the configuration will repeat will be different.
The TSE, which took place on July 31 st 1981- not visible in India, is repeated on August 11, 1999. The TSE of February 16, 1980- seen in India, was repeated on February 26, 1998, but not visible in India.
Unlike a lunar eclipse, a solar eclipse is visible only over a narrow geographical belt or region. A solar eclipse does not last for long, and unless more than 50% of the Sun is covered by the Moon, one will not even notice that a celestial drama is in progress. The periodicity of the solar eclipse was then not wholly established.
Celestial events for viewing pleasure 