How and Why Do Solar Eclipses Occur?

A solar eclipse is a beautiful cosmic event in which you get to see the Sun as a ring of fire. But why exactly does a solar eclipse occur, and why is it advised never to view a solar eclipse with the naked eye? Here’s everything you need to know.

What Is A Solar Eclipse (Why Does They Occur)

Our planet Earth revolves around the Sun in an elliptical path—Earth’s orbit. Similarly, the Moon revolves around the Earth in an elliptical path, which is the Moon’s orbit. There are instances when these three celestial bodies lie in a straight line, resulting in an eclipse.

There are two types of eclipses—solar eclipses and lunar eclipses. A lunar eclipse occurs when the Earth comes in between the Sun and the Moon.

On the other hand, a solar eclipse when the Moon comes in between the Sun and the Earth. During a solar eclipse, the Moon partially or completely blocks the sunlight that is coming from the Sun; as a result, you see a shadow of the Moon on Earth.

A solar eclipse occurs only in the new moon phase. But if there are 12 new moons in a year, then why don’t you get to see an equal number of solar eclipses every year? The reason is the position of the Moon.

As it turns out, the Moon’s orbit around the Earth is tilted by around 5.15° compared to Earth’s orbit around the Sun. Because of this difference, these three bodies only line up intermittently. If the Moon’s orbit were not tilted, a solar eclipse would occur on every new moon—about once a month.

The Moon is only about one quarter the size of Earth, and as a result, is unable to cover the entire Earth with its shadow during a solar eclipse. This is the reason why solar eclipses are not visible from everywhere on the Earth simultaneously and are limited to certain areas. However, this area changes during an eclipse, as a result of the rotation of the Earth and the motion of the Moon in its orbit.

When the Moon comes in between the Earth and the Sun, the Moon casts two types of shadows on the Earth—the umbra and the penumbra. The umbra is a very small and dark shadow that is cast in an area on Earth that is just behind the Moon. The penumbra is a lighter shadow that extends away from the Moon and is cast on the area surrounding the umbra shadow area.

If you are in an area where the umbra is cast, you will get to see that the entire Sun is blocked by the Moon’s shadow. If you are in a penumbra region, you will see that only a small area of the Sun is blocked by the Moon.

Scientists have classified solar eclipses into four types, depending on the type of shadow the Moon casts on the Earth. They are total solar eclipse, annular solar eclipse, partial solar eclipse and hybrid solar eclipse.

Total Solar Eclipse

During a total solar eclipse, the Moon completely blocks the face of the Sun. This solar eclipse occurs when the Moon is at perigee, which is the nearest point the Moon can be to the Earth in its orbit.

A total solar eclipse will only be visible to people who are in a region on which the umbra shadow is cast. Since the Earth keeps on rotating on its axis, the umbra shadow doesn’t remain in a particular area; instead, it keeps moving and the path in which the umbra shadow moves is called the path of totality.

If you’re situated in the umbra region, you will see the sky completely turn dark, and if the weather is good, you will also get to see the outer atmosphere of the Sun, which is more formally called the corona.

Annular Solar Eclipse

An annular solar eclipse is when you get to see the famous ring of fire. This eclipse occurs when the Moon is at apogee, which is the point farthest away from the Earth in the Moon’s orbit. Since the Moon is far away from the Earth, it is able to only partially cover the Sun; as a result, you get to see a ring of fire during this solar eclipse.

Partial Solar Eclipse

A partial solar eclipse occurs when these three bodies are not perfectly lined up. As a result, the Moon is only able to block a part of the Sun. Since the Moon is not completely blocking the Sun, only the penumbra shadow is cast on the Earth.

During this type of solar eclipse, the Sun will appear in a crescent shape. Furthermore, during a total or annular solar eclipse, the area in which the penumbra shadow is cast experiences a partial solar eclipse.

Hybrid Solar Eclipse

During a hybrid solar eclipse, some areas on the Earth experience a total solar eclipse, whereas some areas experience an annular solar eclipse. This eclipse is also known as an annular-total solar eclipse for this reason.

Is It Safe to Watch a Solar Eclipse Without Eclipse Glasses?

The one-word answer is no; you should never watch an eclipse without eclipse glasses or a solar viewer. However, there are exceptions.

During a total solar eclipse, when the Moon completely blocks the Sun’s face (totality), you can watch the eclipse without wearing any protective measures. However, totality only lasts a few minutes, so be absolutely sure

The situation is different in a partial or an annular solar eclipse. In both scenarios, there’s no totality when the Moon completely covers the Sun; as a result, it becomes totally unsafe to view them with the naked eye. To view these eclipses, you should get an ISO 12312-2-certified solar viewer, which is almost 1000 times darker than your regular sunglasses.

You should make sure that you are not viewing an annular or partial solar eclipse through any optical device like a telescope unless it is equipped with a specialized filter. The concentrated solar rays will damage your eyesight. You may not immediately experience any issues with your eyesight after viewing an eclipse with the naked eye, but after a couple of days, you may experience things like headaches, dark spots, and many eyesight problems.

Furthermore, pointing your smartphone’s camera directly towards the Sun to take its photograph may also damage its sensor. Therefore, it’s important to take protective measures to keep your smartphone safe if you are considering taking pictures or videos of solar eclipse using it.

Okay, you’ve got yourself eclipse glasses, but when is the next solar eclipse? Below is the list of the upcoming solar eclipses, along with the regions in which they will be visible.

The next time you see a ring of fire in the sky or find that a dark object is completely blocking the Sun, you will know what’s the reason behind it. But as aforementioned, make sure you have your eye protectors ready with you whenever you are going to watch a solar eclipse.