5 Scintillating Facts about Solar Eclipses and Why They Happen

Solar Eclipses are amazing events, but they are incredibly rare. You'd be lucky to ever see one if you never moved.
Christopher McFadden

Did you know that solar eclipses might become a thing of the past in between 600 million and 1 billion years? Or that they are only visible once every 385 years or so from the same spot on Earth?

No? Then you'll love some of these other very interesting facts about solar eclipses.


What are the three types of solar eclipses?

There are three main types of solar eclipses. They occur, in case you weren't aware, when the Earth passes through the shadow cast by the New Moon, blocking the Sun. 

The New Moon is a phase of the moon when it first appears as a slender crescent shortly after its conjunction with the Sun. It also marks the start of the first lunar phase, and has historically had strong symbolic and spiritual meaning for many societies around the world. 

solar eclipses infographic
Source: Courtesy of timeanddate.com

The three main solar eclipse types are as follows:

Partial Eclipse - Partial eclipses, as the name suggests, occur when the Moon only partially blocks the disk of the sun. 

Annular Eclipse - Annular eclipses occur when the Moon appears smaller than the Sun as it passes centrally across the solar disk. This leads to the formation of a characteristic bright ring, called an annulus, of sunlight around the circumference of the pitch black Moon. 

Total Eclipse (of the sun) - A total eclipse, as compared to other types, is when the Moon completely covers the solar disk (from our point of view).

"Totality during such an eclipse can only be seen from a limited area, shaped like a narrow belt, usually about 160 km (100 mi) wide and 16,000 km (10,000 mi) long," according to TimeandDate.com.

For anyone else outside this narrow belt, you'll only be able to see a partial or annular eclipse (depending on the distance between the Earth, Moon, and Sun). These distances are subject to change throughout the year, and over time

Why do annular solar eclipses sometimes occur instead of total solar eclipses?

As we have previously touched on, total eclipses require some rather specific conditions.

For this to occur, the Moon's diameter and distance from the Earth must make its relative size just large enough to cover the Sun's disk. If the Moon were only slightly closer or further away, then we, on Earth, would only be able to see a partial eclipse.

You might think this is not possible, but the Moon's distance from the Earth varies throughout time.

"In fact, measurements of the distance between Earth and the Moon show that our cosmic companion is slowly spiraling away from us, and in a billion years or so, the Moon will have drifted so far from Earth that total solar eclipses will no longer occur," notes National Geographic

The Moon's orbit around us is also not a precise circle, but is slightly elliptical. This means that the Moon's distance from Earth changes throughout its orbital cycle, so that at times it is closer or farther away. The result, the apparent size of the Moon is not constant. 

Total eclipses appear, on average, every one or two years. Partial and annular eclipses are slightly more common. 

To be lucky enough to observe a total eclipse also depends on your geographic location when the eclipse occurs. Each event is only visible from particular locations, which further reduces your chance of seeing one. 

That's even before we take into account the Moon's orbital plane, which is actually at an angle of a few degrees. To observe a total eclipse, the Earth, Moon, and Sun must be aligned, the Moon's orbital plane must transect the Sun's position, and you must be in the right place on Earth. Only then will you be able to see a total eclipse. 

It is estimated that if you never moved, you would likely only ever see this magnificent event once in your life. 

How often do solar eclipses occur?

As we have already seen, solar eclipses are actually relatively rare events. But that is only really true if you are not able to travel around the world. 

It is estimated that a total eclipse is visible about every 18 months somewhere on the globe. If you were to be fortunate to live long enough and were cemented to the ground for some reason, you would have to wait somewhere between 360 and 410 years between total eclipses. 

But if you can travel, you still need exquisite timing. Every eclipse event usually only lasts a few minutes or so. This is because the Moon is not static, and moves eastward at an average rate of around 3,680 km per hour

solar eclipse total
Source: Yellowstone National Park / Flickr

Total eclipses rarely last for more than seven and a half minutes. In the future, this length will decrease. 

It has been estimated that by the eighth millenium (7000 AD), a Total eclipse should only be able to last for about seven minutes

Here are some facts about solar eclipses

1. There are more than three types of eclipse

Although we have highlighted the three main ones, there is one more type of eclipse. This is called a hybrid eclipse. 

These are when an eclipse event shifts between a total and annular eclipse. Hybrid eclipses can only occur in very special circumstances, and completely depend on where you are on the Earth. 

This form of an eclipse is a very rare event and absolutely stunning to observe.

2. You'll never see a total eclipse at the poles

solar eclipse partial
Partial eclipse. Source: Tomruen / Wikimedia Commons

If you are unfortunate enough, or fortunate enough, depending on your point of view, to live at one of the Earth's poles, you will never be able to see a total eclipse. At these points on the globe, you'll only be able to see a partial eclipse. 

3. Solar eclipses change the weather and bee behavior

During any solar eclipse event, the weather changes noticeably. Data from weather sensors like Lufft's weather sensor WS700 notice an interesting change in weather during a solar eclipse. 

It tends to get cloudier and windier beginning shortly before an eclipse begins, and temperatures tend to drop by around 4 degrees Celsius due to the loss of solar heating. Wind speed drops due to changes in atmospheric turbulence and mixing from the removal of solar heating. 

And the bees? Well, it appears they "go quiet" during solar eclipse events

solar eclipse weather
Source: Luftt

4. You can look into the future during eclipses

According to sites like Luftt.com, during total eclipses, you can catch a glimpse of the future. 

"Although the last total solar eclipse occurred around midday, stars were visible during the phase of totality – as at night. What is to be seen in the sky, however, is not the normal stellar constellation but one that will be seen in several months. On 21 August [2017] it corresponded to the constellation of February 2018," notes Luftt.com.

This happens because the gravitational effect of the Sun bends the light from the stars slightly. This effect is only visible during an eclipse, when stars can be seen during the day.

5. Solar eclipses are but a fleeting phenomena

The Moon is moving further away from the Earth over time. This means that one day in the distant future, solar eclipses will be no more.

In somewhere between 600 million and 1 billion years, the distance between the Earth and Moon will be too great to allow the Moon to fully cover the Sun's disk. Future generations will have to take our word for it that these events occurred at all. 

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