Where does this come from, and can I check it?

The Sun, Moon and node alignment recurs after 223 lunar months. The figure is taken from NASA Science, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a space fact?

Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Eclipses repeat on an 18 year Saros cycle

The Sun, Moon and node alignment recurs after 223 lunar months A Saros cycle lasts 18 years and about 11 days, the time it takes the Moon's orbital geometry to return to nearly the same configuration. Each cycle contains 223 lunar months. Ancient astronomers used the pattern to predict eclipses, and one Saros series produces similar eclipses until the geometry slowly drifts away. It sits in Mondo's space collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NASA Science

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

Go further

Space & Astronomy trivia History trivia

More facts like this

Lunar eclipses glow red because of bent sunlightEarth's atmosphere refracts red light into the shadow that colours the Moon Totality never lasts longer than about seven and a half minutesThe Moon's shadow is small, so you have to travel into its path Lunar dust is sharp enough to scratch glassWith no wind or water to round them, soil grains keep jagged edges The Moon formed from a giant planetary impactA Mars-sized body struck the young Earth and threw debris into orbit The Moon is slowing Earth's spinTidal friction lengthens the day by a couple of milliseconds a century The lunar night falls to about minus 173 CelsiusWith no air to hold heat, the surface swings hundreds of degrees a day

Tags: eclipses, saros, moon

Eclipses repeat on an 18 year Saros cycle: the short answers

Where does this come from, and can I check it?: The Sun, Moon and node alignment recurs after 223 lunar months. The figure is taken from NASA Science, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a space fact?: Yes. It sits on the Space shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.