What should you pay attention to during the total solar eclipse?

By | April 2, 2024

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When the total solar eclipse passes through Mexico, the United States and Canada on April 8, spectators can expect a host of awe-inspiring moments.

During a total solar eclipse, the moon completely blocks the face of the sun for a brief period known as totality — and 32 million people in the U.S. who find themselves along the 115-mile-wide path of totality for the April event will get the chance to enjoy this full expression of the heavenly spectacle.

It’s worth pausing and taking in this historic celestial event, as a total solar eclipse won’t be visible again in the contiguous U.S. until August 2044, and an annular solar eclipse, where the moon doesn’t reach the sun can completely block, won. won’t appear again in this part of the world until 2046.

“Until you’ve actually seen (a total solar eclipse), it’s almost impossible to describe,” says Dr. John Mulchaey, deputy scientist at the Carnegie Institution for Science and director and Crawford H. Greenewalt chairman of the Carnegie Observatories. “When you see the totality, you can see how it has had such a huge impact on humans for thousands of years. It is one of the most beautiful things most people will ever experience.”

The sun's corona, or hot outer atmosphere, is visible as the moon passes in front of the sun during a total solar eclipse at the Big Summit Prairie ranch in Oregon's Ochoco National Forest on August 21, 2017. - Robyn Beck/AFP/ Getty ImagesThe sun's corona, or hot outer atmosphere, is visible as the moon passes in front of the sun during a total solar eclipse at the Big Summit Prairie ranch in Oregon's Ochoco National Forest on August 21, 2017. - Robyn Beck/AFP/ Getty Images

The sun’s corona, or hot outer atmosphere, is visible as the moon passes in front of the sun during a total solar eclipse at the Big Summit Prairie ranch in Oregon’s Ochoco National Forest on August 21, 2017. – Robyn Beck/AFP/ Getty Images

But the phases surrounding totality — including a few phenomena so stunning they’ve been given their own names — are also quite memorable, eclipse experts say. Here you can read what you should pay attention to.

What should you pay attention to during the solar eclipse?

The moon does not suddenly appear between the earth and the sun; the event begins with a partial solar eclipse, during which the moon appears to take a “bite” out of the sun. Depending on your location, the partial solar eclipse could last between 70 and 80 minutes, according to NASA.

For those living outside the path of totality, a crescentic partial solar eclipse, rather than a total solar eclipse, will be the main event.

Within the path, the partial eclipse is the longest phase, but as the time for totality approaches, watch for changes in the sky’s appearance.

A partial solar eclipse is seen between the clouds from Socorro in Sao Paulo, Brazil on October 14, 2023. - Igor do Vale/Sipa/APA partial solar eclipse is seen between the clouds from Socorro in Sao Paulo, Brazil on October 14, 2023. - Igor do Vale/Sipa/AP

A partial solar eclipse is seen between the clouds from Socorro in Sao Paulo, Brazil on October 14, 2023. – Igor do Vale/Sipa/AP

“About 15 to 20 minutes before totality, the sky starts to turn a very strange, gloomy color,” Mulchaey said. “It almost looks gray because the sun is so high in the sky, but it’s almost completely blocked. It is not like twilight, sunset or sunrise when (the sun) is low in the sky. It’s above you. And suddenly you lose most of the sunlight, and that feels very strange.”

The eerily darkening sky is a sign to skywatchers that the star show is about to begin. Make sure you have eclipse glasses on hand so you can safely view the sun before the event starts.

Two breathtaking phases occur in the final moments before totality, Mulchaey said.

When the moon begins to cross in front of the sun, the star’s rays will shine around valleys on the moon’s horizon, creating glowing droplets of light around the moon called Baily’s beads. The phenomenon is named after the English astronomer Francis Baily, who noticed it during an annular solar eclipse on May 15, 1836.

Baily's beads can be seen around the left side of the moon just a second before it completely covers the sun.  - Heinz-Peter Bader/X00316/ReutersBaily's beads can be seen around the left side of the moon just a second before it completely covers the sun.  - Heinz-Peter Bader/X00316/Reuters

Baily’s beads can be seen around the left side of the moon just a second before it completely covers the sun. – Heinz-Peter Bader/X00316/Reuters

As totality approaches, Baily’s beads will quickly disappear, giving way to the “diamond ring,” a nickname for what it looks like when only one bright spot remains – like a glittering giant diamond ring.

Both phases last less than a minute, Mulchaey said.

Then it is time for totality.

Prepare for totality

The totality phase of the April 8 eclipse is expected to last twice as long as in 2017 because the moon is currently closer to the sun. Those standing right along the centerline of the path will see a total solar eclipse lasting between 3½ and 4 minutes, according to NASA.

“Suddenly totality happens and the corona emerges,” Mulchaey said. “Even though it’s dark outside, it’s glorious somehow.”

The corona is the sun’s ultra-hot outer atmosphere, which emits a glow that can be seen around the moon during the solar eclipse. Normally the corona is difficult to see because the surface of the sun is so much brighter. During the total solar eclipse, the corona will appear like streams of white light, according to NASA.

The diamond ring effect can be seen during the total solar eclipse on August 21, 2017 in St. Louis, Missouri.  - Tim Spyers/Icon Sportswire/Getty ImagesThe diamond ring effect can be seen during the total solar eclipse on August 21, 2017 in St. Louis, Missouri.  - Tim Spyers/Icon Sportswire/Getty Images

The diamond ring effect can be seen during the total solar eclipse on August 21, 2017 in St. Louis, Missouri. – Tim Spyers/Icon Sportswire/Getty Images

During the 2017 solar eclipse, the sun was approaching solar minimum, or the quiescent phase of our star’s eleven-year activity cycle. Now the sun is approaching solar maximum, when the sun is exceptionally active, Mulchaey said. The corona will likely appear brighter and fuller, and there may be a chance to see flared loops of solar activity that resemble streamers in the corona during the eclipse.

Spectators may also be able to see a region of the solar atmosphere called the chromosphere, which will appear as a thin, pink circle around the moon.

Bright stars or planets such as Venus may shine in the dark sky, and the air temperature will drop as the sun disappears. The sudden darkness also causes animals to behave unusually.

“We may see nocturnal behavior, such as crickets chirping or bats emerging, and animals that inhibit daytime behavior, such as birds going to sleep or flying insects landing,” said Dr. Andrew Farnsworth, visiting scientist at the Cornell Lab of Ornithology.

After totality ends, Baily’s diamond ring and beads will briefly reappear before the partial solar eclipse returns as the moon moves slowly across the sun.

Why we have eclipses on Earth

It’s been just six years since a total solar eclipse crossed the US. The path of the April 8 solar eclipse is very different: it runs from west to east.

On average, a solar eclipse occurs in the same place every 375 years, Mulchaey said.

And we’re living at the right time to really enjoy the sight of a total solar eclipse on Earth, he said.

Although eclipses occur all over the solar system, none are exactly like those on our world.

The moon is about 400 times smaller than the sun, but the moon is also about 400 times closer to Earth than the sun, creating a “beautiful coincidence” that results in eclipses when the three celestial bodies align, Mulchaey said.

This alignment is called syzygia, or when three objects in space line up.

In the distant past, the moon was much closer to Earth, meaning totality probably didn’t look like it does today. And in about another 60 million years, the moon will be so far away that it will never cover the sun, making this a rare moment, Mulchaey said.

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