Along with Lunar Eclipses
Why?
Because the Moon is rotating around the Earth and its position changes a little bit with each time it goes around the Earth. Therefore, if there was an eclipse one month it is likely there will be one next month.
We all know that for an eclipse to occur the Earth, Sun and Moon must be in alignment. The Sun and the Earth are always in alignment so what we are really talking about is the alignment of the Moon. If the Moon is between the Earth and the Sun it is a solar eclipse. If the Moon is behind the Earth it is a lunar eclipse.
If you think of a giant sheet going out from the alignment of the Earth and the Sun then the only time an eclipse can take place is when the Moon is piercing that sheet, which is called The Solar Plane. Think about this if the Moon is in alginment with the Earth and the Sun then an eclipse will happen (lunar or solar). If you were to describe the position of the Moon each of those times as pinpricks in the Solar Plane there would be a bunch of them grouped at a certain time. That grouping and the next time this happens is known as The Saros Cycle and it happens every 18 years 14 days and 8 hours. The eight hours is the thing to pay attention to.
Eight hours is one third of day. This means that the next time the cycle of eclipses happens it will be one third of the way farther around the Earth. That translates to 120 degrees west of the last cycle. Because there are 360 degrees of longitude in the Earth and one third of that is 120 degrees.
Pretty cool.
Astronomers much up this rather simple explanatin with a lot of terms, and i understand why. It’s not an accurate enough explanation to actually accurtely predict the next ecplise.
Here’s one example of that muckery. We say a year is 365 and a quarter long (about). This is a measurement of the Earth moving around the Sun. But remember each day the Earth moves a bit in rotation every day. How much? About a degree – there are 360 dgrees and 365 days in a year. So how many roations does the Earth do in a year? I think 364 around itself and one more for circling the Sun. I think that’s the way it works.
Or as AI explains:
The Saros cycle is a period of 18 years, 11 days, and 8 hours (about 6,585.3 days) used to predict solar and lunar eclipses. After this exact time, the Sun, Earth, and Moon line up again in nearly the same geometry, causing a very similar eclipse to repeat. [1, 2]
or Wikipedia
How the Cycle Works
- The cycle matches up 223 synodic months (lunar phases) with 242 draconic months (node passes) and 239 anomalistic months (perigee distances). [1]
- Because of the extra 8 hours in the cycle, the Earth rotates another one-third of a turn. This means the next matching eclipse happens 120 degrees further west on the globe. [1, 2]
fascinating . . .