Here’s what you’ll see in a total solar eclipse

Our past columns about the eclipse covered topics like an eclipse’s effect on history and observing safety. Now, with the eclipse less than four months away, we’re getting into specifics — what you’ll see, why do eclipses happen, and why do people travel, often great distances, to see them.

Today, we’ll look at what you’ll see — assuming it isn’t snowing or raining. This is Lamoille County, after all.

Imagine that you have two quarters on top of each other but offset. The bottom quarter is the sun, the upper one is the moon. If you’re thinking that this can’t work because the sun is about 400 times larger than the moon, it still works because the sun is also about 400 times further away from us than the moon.

At the risk of being a nag, remember to wear eclipse glasses as you observe the eclipse.

As the eclipse starts, the moon covers an increasingly larger portion of the sun, creating an increasingly larger shadowed crescent. It is as if you’re sliding the upper quarter over an increasingly large part of the lower one. (See the first three images in the photo)

As more and more of the sun gets covered, you’ll start to see a reddish glow around the sun and a series of small lights along the edge. (Fourth image)

The glow is the chromosphere, a part of the sun’s atmosphere that appears as the moon obstructs more and more of the sun’s light.

The bright spots along the rim are called Baily’s Beads. They’re caused by sunlight shining through valleys and mountain passes on the moon and are briefly visible just before and after totality. They were named for British astronomer Francis Baily who explained them after an eclipse in 1836.

As more of the sun gets covered, there’s one Baily’s Bead left. That bead, at the edge of the sun, is called the Diamond Ring, for obvious reasons. It’s not uncommon for there to be additional Baily’s Beads on either side of the diamond, making it look more like a jeweled diamond ring. To continue the coin analogy, as more and more of the sun gets covered, the sun light has fewer and fewer channels to get past the upper one. (Fifth image)

The next step is totality, or total eclipse. During that time, a bit over three minutes in Morristown, we’ll see the corona, the outermost part of the sun’s atmosphere. The sun is so bright that we won’t be able to see the corona without special instruments. However, as more and more of the sun gets obscured, the sun dims enough that we can see the corona by eye — using solar glasses, of course. (See note 3 below)

After totality, the process reverses. If you took the solar glasses off, remember to put them back on as soon as you start to see the sun’s light again.

In summary

To paraphrase the summary from an earlier column, a solar eclipse is a dance between two heavenly bodies 250,000 and 93 million miles away. The coming eclipse is a rare chance to see that dance from our own backyards.

Note 1: A comet may be visible during the eclipse. See bit.ly/41JmlGJ or search for “viewing a comet during 2024 solar eclipse.”

Note 2: During totality, you should be able to see the planets Mercury and Venus and possibly Jupiter. However, things will be happening so fast with the eclipse that you won’t have much time for this.

Note 3: Technically, you don’t need the solar glasses when viewing the corona during totality. That’s the one time you can view the sun directly by eye. Once totality begins, most apps will say “safe to remove glasses.” However, you’ll be busy enough during totality that you can forget to put the glasses back on. Whatever you do, just be safe.

This column has been updated.

Neil Perlin is a retired computer consultant, a longtime amateur astronomer, and a member of the Lamoille County Star Gazers, Vermont Astronomical Society and Amateur Telescope Makers of Boston.

Lamoille County Star Gazers is a group of amateur astronomers from Morrisville, Hyde Park and Elmore. The group holds public observation sessions at the observatory at Peoples Academy and other special events to look at the sun, moon, planets and more. If you own a telescope and want to use it with a group of like-minded people, come observe. You don’t need to be a scientist; you just need to be curious about what’s in the sky. To learn more, email lcvtsg@gmail.com.