What will it be like to experience the total solar eclipse 2024?

Why chase eclipses, especially total eclipses, often referred to as nature's most spectacular events? 

There are possibly as many answers to that question as there are people who delight in the visual excitement encountered within the shadow of the moon: the eerie light enveloping everything just before the sun is blotted from the sky; the diamond ring seemingly exploding overhead; the solar corona different on each occasion; stars and planets shining at midday; the reactions of flowers, birds and animals within the shadow; the strange glow all around the horizon; people crying, yelling; praying. No other celestial occurrence evokes such intense and varied response. For a brief time, the world of eclipse chasers is totally transformed. 

A total eclipse of the sun is without a doubt, the greatest cosmic pageant that can be witnessed. The sight of the sun in totality during the 2024 total solar eclipse on April 8 may last 4 minutes 28 seconds in parts of Mexico and will average just over four minutes in its sweep across the southern and eastern United States.

Related: Total solar eclipse live blog 

The moon will cross the sun's disk from the southwest and the "wall of darkness" associated with the moon's dark umbral shadow will rush from the Pacific coast of Mexico to the Atlantic coast of Canada at an average speed of 2,110 miles (3,400 km) per hour. 

The daytime darkness will devour portions of 15 states: Texas, Oklahoma, Arkansas, Tennessee, Missouri, Kentucky, Illinois, Indiana, Ohio, Michigan, Pennsylvania, New York, Vermont, New Hampshire and Maine. Only those inside the path of totality will have a chance to enjoy the brilliant show in the sky. The tiniest dot or thread of sunlight will spoil it all. The delicate pearl-tinted halo known as the corona and the blood-red feathery markings called the prominences are visible only to those who see the total eclipse. The sun is 398,000 times brighter than a full moon, so the least trace of sunlight ends the spectacle. 

The sky will be greatly darkened for those just outside the totality path (such as St. Louis and Cincinnati), but the brilliant cosmic performance will not be visible to them. There are an estimated 32 million people who live within the path. Countless millions more are expected to journey from all over the world to see the eclipse. 

About 75 minutes before the total phase, the dark edge of the moon will produce a small scallop in the disk of the sun. Slowly it will glide across the face of the sun, gradually cutting it down to a crescent. Finally, the sun will be a mere curved thread of light boarding the eastern (left) edge of the moon's silhouette. 

During this period, while the moon is gradually erasing the sun, there will be a strong temptation to gaze steadily at the spectacle. 

This should not be done.

You should bring a fresh vision to the series of rare and wonderful sights that begin to take place as the waning crescent ultimately disintegrates into irregular dots and points of light. Twenty minutes before totality, to enhance the darkening effect, wear a patch over one of your eyes and remove it as totality sets in.  

The table below, provides local circumstances for 15 cities that are within the path of totality. Column 4 gives the time of start of totality to the nearest second; Column 5 provides the duration of totality in minutes and seconds. So, (as an example), in Cape Girardeau, Missouri, totality begins at 1:58:18 p.m. Central Daylight Time and with a duration of 4 minutes 06 seconds, the sun will not begin to reemerge until 2:02:24 p.m. 

By the time about 80-percent of the sun is covered, the sky illumination will appear rather peculiar. Also, the shadows are becoming sharper as the sun . . . now reduced to a thick crescent shape . . . continues to get thinner and thinner. As totality draws nearer and the sky grows still darker, you might begin to feel a little nervous, for here is a situation that neither you nor any of the people who might be around you have any control over. Only now can you begin to understand why eclipses both fascinated and terrified ancient people. The final few minutes before totality are always filled with indescribable excitement.  

Beads, bands and beauty

As the crescent fades to a thin filament of light, it will not go out like a snuffed candle, but will break up into what are known as "Baily's Beads." This is due to the fact that the moon's disk is very rugged and mountainous. As an analogy, its profile is something like the circumference of a circular saw. That rugged edge will cause the remaining hairline crescent to break up into beads of light; the remaining sunlight streaming through the mountains and valleys of the moon.

The beads got their name from the minute and vivid description of them which was written by Francis Baily after he observed them in the eclipse of May 15, 1836. He was not the first to record them however. Observations of the beads from different locations along the totality path have made it possible for astronomers to turn out accurate maps of a slice of the moon's surface and to survey mountains and valleys which on this occasion, are some 223,000 miles (359,000 km) away. 

Just before the beads come into sight, the "shadow band" effect begins to take shape. Instead of a regular deepening of shadows, black and white lines begin to stripe the Earth. These bands are — generally speaking — about 1 or 2 inches wide, with intervening bright stripes about 3 inches wide. Sometimes they move sedately. Sometimes they flicker. Sometimes they rush by. 

Though countless observations of them have been made over the years, to this day nobody knows exactly what causes the bands. The usual belief is that the exceedingly thin stream of sunlight that passes the moon just before and just after the total eclipse is distorted by our turbulent atmosphere, just as the light of the stars is disturbed making them appear to twinkle. 

Diamond Ring . . . then darkness

Just moments before totality, the beads coalesce into one spot of sunlight and an explosion of light brightens the region around the eclipse. A thin ring of light — the inner corona — begins to encircle the darkened sun; this final bit of sunlight produces a shaft of light piercing the sky and resembling the glow of a brilliant diamond. Together with the thin ring surrounding the darkened sun, the eclipse appears to create a magnificent diamond ring hovering for a moment around the eclipse. Accompanying gasps, shouts, screams . . . you may even be shouting too . . . all attest to the tremendous impact this diamond ring effect has on observers. 

Now it is safe for you to look directly up at the sun!

Then, the dark lunar shadow which belongs to the total eclipse will rush in. Those who are on the lookout for its approach should concentrate on the west-southwest sky, a few minutes before totality, watching the horizon darken dramatically as if a severe thunderstorm was brewing. In the final seconds before totality, you might notice quick color changes of slate, violet, amber and deep red just out ahead of the advancing shadow. The rather clammy light of the remaining thread of sun will seem to rush out in a deathly silence as if suddenly immersed in a vacuum. The moment that the shadow's leading edge passes overhead, totality begins. 

The crown of the sun

All around the black eclipsed sun, a bright halo suddenly appears: the corona. 

Pearly white and as bright as a full moon it extends outward from the eclipsed sun three to five times the diameter of the sun (3 to 5 million miles/5 to 8 million km!). Its first sight is a climax to the tremendous drama that has been building during the previous 10 minutes. The corona is always present surrounding the sun, but the brilliance of the sun normally overpowers it, rendering it invisible except during total solar eclipses, or when viewed through a special telescope called a coronagraph which blocks out the brilliant sun. The corona is brightest as it emerges from the sun, gradually becoming dimmer farther away from the sun. The outer edge of the corona is ragged. Thin dark lines extend outward from the sun into the corona. They tend to be most numerous about the poles of the sun and are sometimes referred to as "polar brushes." 

Here is the climax of the phenomenon: The most impressive and brilliant spectacle in nature, surpassing the sight of any great comet or any northern lights display. 

After witnessing his first total eclipse in 1925, Dutch-American astronomer Willem Jacob Luyten wrote: 

"No language will ever be adequate to describe its divine beauty; if you have seen it, the magnificence of the corona will forever stay in your memory with ineffaceable accuracy as the most overwhelming spectacle that nature affords."

At this moment you might ask yourself if this is really happening, or is it a dream? Of course, it is all real, but still hard to believe. Interestingly enough, after the initial screaming and shouting, most people quickly calm down and settle into a sort of quiet happiness as they scan the weird scene and try to enjoy as many of the fantastically strange sights as possible during the all-too-short interval of total eclipse. 

Prominences

Just as one begins to recover from the impact of the sudden appearance of the corona, rubies seem to hover around the black disk of the moon. These are solar prominences. Sometimes only one, and at other times as many as five or six can be observed penetrating a few thousand miles into the corona. These are tongues of incandescent hydrogen gas rising above the surface of the sun far enough to be visible beyond and above the eclipsing moon. You'll get a very good view of them using binoculars or better still, a telescope, for like the corona you see them directly without the use of filters or viewing screens during totality.  

The size and number of the prominences and the area and brightness of the corona will depend on conditions of the sun's "surface" — the photosphere. The corona is electrically charged matter rushing outward from the sun at a few million miles an hour. The number and distribution of sunspots on the photosphere affect the shape of the corona. They are products of the variable magnetic activity on the solar surface. When there are many spots stirring up on the sun, the corona is larger and brighter and prominences are also more numerous. NOAA now expects the peak of solar activity will take place anytime between now and October 2024. So, on April 8, the corona may appear globular, very bright and quite imposing, with several notable streamers protruding out in different directions, perhaps also accompanied by a few prominences of note. 

Sky illumination; stars and planets

The light from the corona, combined with the light that filters through the uneclipsed parts of the sky (such as just outside the moon's dark shadow), will make illumination of the sky during totality similar to about a half hour after sunset or before sunrise. It will be a strange, unearthly illumination, unlike any dusk or dawn you have ever experienced.

As totality begins, some of the brightest stars and planets will appear. Practically exploding into view about 15 degrees to the lower right of the sun (your clenched fist held at arm's length measures 10 degrees) will be the brilliant planet Venus — the third brightest object in the sky; it likely will already be evident some minutes before totality. About 30 degrees to the upper left of the sun will shine the second brightest planet, Jupiter. These two planets will most likely be the two most notable objects other than the eclipsed sun itself. 

Meanwhile, well up in the east-northeast sky will be the bright star Capella. Lower toward the east-southeast will glow Betelgeuse and Rigel, while nearer to the horizon will be Sirius, the brightest star in the sky, possibly visible along the eclipse track starting from Arkansas and all points northeast. A few fainter stars might appear here and there, but the combined light of the corona and the glow surrounding the horizon will quench the rest of the stars. The combination of darkness and starlight at midday always helps to create a lasting memory of a total eclipse. 

Another "Diamond Ring" heralds the end

Veteran observers who view with optical aid should be alert for the return of the sun. Generally, the appearance of a ruby-red arc of light along the moon's dark edge — the solar chromosphere — portends the blinding photosphere by several seconds; consider this as the "red-flag" that the end of totality is near at hand. Heed the warning and look away without delay. Totality's end will be signaled by the appearance on the sun's western rim (where the first "bite" appeared a bit more than an hour before) of a brilliant solitaire of light, again set on the thin, luminous ring of the inner corona. The streamers of light instantly vanish; the gem grows brighter; the stars and planets fade away. The return of this "Diamond Ring" in the sky, quickly becomes too dazzling to look at. 

Totality is over, but it ends in magnificent fashion! 

More than 99 percent of the sun is still covered, and yet compared to what it was like only moments ago, it seems like almost full daylight has returned. Now you can understand why we have been urging you to get into the path of totality, for even with this tiniest bit of the sun left uncovered, you would miss so much!

The temperature may have dipped several degrees or more, and all of the phenomena seen prior to totality now appear again — in reverse order — as the moon glides away from the sun's disk. These things can be looked at afterward just as well as beforehand, and as there is nothing that requires the eye to be very sensitive after the eclipse is over, it is best to look at them then. 

Final thoughts

Anyone who has experienced a total solar eclipse, no doubt has observed that within the moon's shadow, the sky grows rapidly darker, birds sing evening songs and go to roost, flowers may close, the air cools, and the landscape takes on a strange saffron coloring. And after the initial whoops and hollers of spectators witnessing this incredible celestial drama, most fall silent. All of these things are major parts of the eclipse mystique, and people travel around the world to experience it. It becomes obvious that totality affects all living creatures. All stare skyward, exempt from all worldly problems for those brief but glorious moments of totality. 

To them, a total solar eclipse is awesome, mysterious, an event never to be forgotten! 

How sad it is that at past eclipses some people have actually covered their eyes or looked away from the sun during totality . . . even running into their homes to hide. By doing so, they missed out on what truly is the greatest show on Earth!

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications.