In ancient China, the solar eclipse was interpreted as the celestials attacking the sun. In Native American folklore, the solar eclipse represents a black squirrel gnawing at the sun. These examples show that human fascination with solar eclipses, or the “darkening of the sun,” has always existed.
We know how lunar and solar eclipses happen and can anticipate them, but they’re no less impressive and exciting to observe.
Learning how and when it happens is crucial to ensure that you are well-prepared for the next solar eclipse. Also, knowing the right way to observe a solar eclipse is essential.
What Is a Solar Eclipse?
A solar eclipse is one of the most spectacular astronomical events and occurs when the moon blocks the sun, casting a shadow on the Earth. One of the essential details about solar eclipses is that they can only happen during the new moon.
The new moon is sometimes called “Black Moon” or even “No Moon.” This is because it represents the complete alignment of the moon between the sun and the Earth.
Some interpret the occurrence of the new moon as the opposite of the full moon. Or the event when the side of the moon is fully illuminated by the sun, and the Earth’s satellite planet is the brightest and most visible.
The moon’s shadow is not large enough to cover the entire planet, so the shadow is limited to a specific area that constantly changes. That’s because both the Earth and the moon are in perpetual motion.
Our planet revolves around its axis and orbits the sun, and the moon circles the Earth, thus causing solar eclipses to “travel” from one location to another.
Four Types of Solar Eclipses
The magnitude of the solar eclipse, or how much of the sun’s disk is eclipsed, determines which part of the moon’s shadow falls on the Earth. Astronomy classifies four solar eclipse types: partial, annular, total, and hybrid.
Partial Solar Eclipses
As the name implies, partial solar eclipses describe the moon partially covering the sun’s disk. It means that all three celestial bodies are not in perfect alignment, and only the outer part of the moon’s shadow, or the penumbra, is cast on the Earth.
Partial solar eclipses are the most common type and comprise 35% of all solar eclipses. Because the moon’s penumbral shadow is large, it also means that this type of solar eclipse is the most visible from different locations around the globe, although they are most common in places surrounding the Earth’s poles.
There are three phases of the partial solar eclipse.
- The beginning – the moon moves over the sun’s disk
- Maximum eclipse – the full magnitude is reached
- The end – the partial solar eclipse no longer covers the sun
Annular Solar Eclipses
Perhaps one of the most memorable astronomical events is the annular solar eclipse, which accounts for 32% of all solar eclipses. This phenomenon includes the moon covering the sun’s center; the outer edges of our star are visible, thus creating the “ring of fire.”
The annular eclipse got its name from the Latin word for ring, “annulus.” Remember that solar eclipses are named according to the maximum points of each type of eclipse, which are very brief. Therefore, for most of its duration, the annular solar eclipse resembles the partial solar eclipse.
The annular solar eclipse includes the following five stages.
- First contact – The partial eclipse starts, and the sun appears as if the moon has “taken a bite” from it
- Second contact – The annular eclipse starts, and the ring of fire appears
- Maximum eclipse – The Moon fully covers the sun’s disk, and the annularity is perfect
- Third contact – The ring of fire starts disappearing as the moon moves away from the sun’s disk
- Fourth contact – The end of the partial eclipse and the moon entirely stops covering the sun
Total Solar Eclipses
When the moon completely covers the sun’s disk, we’re fortunate to witness a total solar eclipse, one of nature’s most amazing spectacles. During the total solar eclipse, the moon goes through the other, darker moon’s shadow called the umbra, which entirely blocks the sunlight.
You might wonder how it is possible for the sun, whose nearly 865,000-mile diameter, can even be blocked by Earth’s only natural satellite, which is 400 times smaller. Remember that the moon is significantly closer to the Earth than the sun.
When these celestial bodies align in ideal conditions, the moon can entirely block out the sun. As a result, total eclipses make up 28% of all solar eclipses. The solar eclipse’s totality lasts up to seven minutes, though they’re usually shorter.
As the moon totally covers the sun, we can see the sun’s outer atmosphere, called the corona, which reveals a beautiful, white glow. Again, by scientific convention, solar eclipses are named by their darkest stage, even if it appears only at one point on Earth.
Total solar eclipses have five distinct phases.
- First contact – The partial eclipse begins, and the moon starts covering the sun’s disk
- Second contact – This stage happens a few minutes before the total eclipse can be distinguished by Baily’s Beads, the visual effect created by the moon’s mountains and craters
- Total solar eclipse – The entire surface of the sun is covered by the moon, and the star’s outer atmosphere is visible
- Third contact – The moon starts moving away from the sun, and Baily’s Beads might appear again
- Fourth contact – The moon entirely moves away from the sun, and the total solar eclipse ends
Hybrid Solar Eclipse
Finally, the pretty rare hybrid solar eclipse may appear as an annular or total solar eclipse, depending on the observer’s location. Hybrid solar eclipses are also called annular-total or A-T eclipses.
The hybrid eclipse starts as annular, reaches eclipse totality, and returns to the annular form as it passes. Hybrid eclipses are rare and account for only 5% of all solar eclipses.
Why Don’t We See Solar Eclipses at Every New Moon?
If the solar eclipse only occurs during the new moon, it’s natural to wonder why they aren’t more common. There’s a straightforward explanation for this.
The moon’s orbit is slightly over 5 degrees relative to Earth’s, so the moon’s shadow typically goes above or below our planet. Still, solar eclipses are not that uncommon and happen between two and four times per year.
When discussing total solar eclipses, the totality is only visible in a 50-mile radius in certain areas on Earth. Therefore, total eclipses visible from anywhere on Earth are extremely rare and happen every 100 years or so, sometimes even less frequently.
What Are Solar Eclipse Cycles?
Perhaps a less-known fact about solar eclipses is that they occur in cycles. For example, one of the most researched solar eclipse cycles is called the Saros cycle, and it happens every 18 years, which was known even by ancient Babylonians.
The solar eclipses that occur at the beginning and the end of the Saros cycle have the same geometry, and the moon will be in the same lunar node and distance from the Earth.
Are Solar Eclipses Dangerous?
When a solar eclipse is announced, advice is attached on how to protect your eyesight while still enjoying the eclipse.
That makes perfect sense because we’re not meant to stare at the sun anyway, as it can cause solar retinopathy, a condition caused by too much ultraviolet light coming in contact with the retina. Moreover, looking straight at the sun, whether to see the eclipse or for any other reason, is painful and, in extreme cases, can cause blindness.
In fact, the only time you can directly look at the sun briefly is during the total solar eclipse in the precise moment of totality. Regular sunglasses are not sufficient protection, but you may search for special eclipse glasses in a local science museum or astronomy club.
Many people want to take solar eclipse photographs but aren’t sure if it’s safe. The only way to do it without exposing your eyesight to damage is to purchase a professional solar filter that can reduce the sun’s brightness sufficiently while not destroying the camera.
Solar vs. Lunar Eclipses
Lunar eclipses are another fascinating astronomical phenomenon caused by the Earth blocking the sun from reaching the moon. Lunar eclipses can be penumbral, partial, or total (umbral), depending on the type of shadow that falls on the moon.
Unlike solar eclipses, you can watch a lunar eclipse with the naked eye, and it’s easier to see from Earth. Naturally, solar eclipses are observed during the day and lunar only at night. However, they are both beautiful in their own right and have always held special significance in human history and in different cultures.
The Power of the Solar Eclipse
Eclipses, both lunar and solar, while extremely fascinating, were considered bad omens throughout most of history. For example, it is written that some thought the 1652 solar eclipse was the catalyst for the Great Plague, aka the Black Death.
Sometimes the eclipses were considered the cause of tragic events years after they passed, as is the case with King Henry I in 1135, who died two years after the solar eclipse occurred.
Whether solar eclipses are feared or admired, they are an inevitable part of human existence and always will be. We’re fortunate to live during the times when astronomical discoveries offer valuable insight into how the Earth, moon, and the sun relate to one another.