MGA Faculty Q&A With Dr. Lawrence Camarota: The April 8 Total Solar Eclipse

Author: Sheron Smith
Posted: Thursday, March 7, 2024 12:00 AM
Categories: Students | School of Health and Natural Sciences | Pressroom | Faculty/Staff

Macon, GA

Graphic: Alexandria Brooks

Inquiring minds want to know: Will those of us in the Middle Georgia region get to experience the celestial spectacle of the April 8 total solar eclipse? (Spoiler alert: We’ll be able to see about 80 percent of it, weather permitting.) We turn to Dr. Lawrence Camarota of MGA's Department of Natural Sciences for this Q&A about the upcoming solar eclipse.

(BTW, the MGA student org Natural Sciences Network is hosting a “watch party” in front of the Student Life Center on the Macon Campus beginning at 1:45 p.m. Monday, April 8. They’ll have eclipse glasses to borrow and possibly a solar telescope set up.)

Can you provide some background on what a solar eclipse is and why it's such a significant astronomical event?

A solar eclipse occurs when the Earth, the moon, and the sun all align in space, with the moon in the middle. If you were watching the surface of the Earth from space, you would see the shadow of the moon racing across the surface of the Earth. When seen from the Earth, the moon will cover up a part of the sun. Solar eclipses generally occur every six months, but you would only see one if you were in the moon’s shadow. Any given solar eclipse is only visible to approximately 15 percent of the Earth’s surface, and total solar eclipses are generally visible to less than 1 percent.

Part of a solar eclipse's significance is that it is such an unusual event. On any given location of the Earth, partial solar eclipses are typically many years apart, and total solar eclipses are events that one generally must travel to. But more than that, eclipses are significant for their visual appearance, ranging from the odd shadows cast during a partial eclipse to the breathtaking beauty of seeing the solar corona during a total eclipse.

How does the upcoming April 8 solar eclipse of 2024 compare to previous eclipses, especially the one that took place in 2017, in terms of visibility and magnitude?

Overall, the main difference between eclipses is the apparent size of the moon during the eclipse, and where the shadow is cast. The moon’s orbit around the Earth is slightly eccentric, meaning that it gets closer and farther over its orbital period. At perigee the moon is at its closest point and appears larger in the sky; at apogee the moon is at its farthest point and appears smaller in the sky. If the solar eclipse happens when the moon is at apogee, then the moon will not be able to cover the sun completely from any point of view. This is called an annular eclipse.

However, from the perspective of a person on the ground, eclipses can vary wildly in how much of the sun is covered. In 2017, the path of totality went through the northeast corner of Georgia. For this eclipse, the path of totality is farther away, so it will not be as deep. However, it will be nothing to sneeze at, roughly 80% of the sun will be covered when the eclipse is at its maximum.

What specific regions will be able to witness the total solar eclipse, and what makes those areas particularly significant for viewing? How much of it will we be able to see in the central Georgia region?

The path of totality for this eclipse follows a curving line from the southwest region of Texas through the middle of Maine. The eclipse will be partially visible to almost all of the contiguous United States, along with Mexico, many Central American countries, and the westernmost parts of Europe.

Here in central Georgia we will be able to see the eclipse from around 1:45 through 4:20 p.m., with the maximum around 3:05. At maximum, around 80 percent of the sun will be covered by the moon.

What safety precautions should people take when viewing a solar eclipse, especially if they're in the path of totality?

The most important thing to remember when viewing an eclipse is DO NOT LOOK DIRECTLY AT THE SUN WITH YOUR BARE EYES. The sun is bright enough to burn your retina, and being partially covered does not change that; in fact, the partial eclipse can be even more dangerous as our eyes adjust to gather more light in the slightly dimmer conditions. If you want to see the eclipse, you can either look directly with a light filter, or by an indirect projection. If you want to look directly at the eclipse, you will need eclipse glasses. They can be fairly cheap, but make sure that they are explicitly eclipse glasses. Do not trust any DIY/lifehack that you read about online for direct viewing. Even with eclipse glasses, you do not want to stare at the sun; look at it for a few seconds, then look away for a minute.

Indirect viewing is fairly simple; any small hole will create a projection of the eclipse. One easy way to see this is to take two index cards and punch a small hole in one. Hold the cards so that the one with the hole is a couple inches above the other card. The spot of light from the hole will be shaped like the eclipse. This phenomenon will also tend to occur naturally; for example, the spots of light in tree shadows will take on the shape of the eclipse. There are also more complicated viewers that you can make that will produce a stronger image, and for indirect viewing they are safe enough to make yourself, as long as you, again, DO NOT LOOK DIRECTLY AT THE SUN WITH YOUR BARE EYES.

If you are going to see a total eclipse, the period of totality is the only time that it is safe to look at the eclipse with your bare eyes. If you are going to see a total solar eclipse, look up ahead of time exactly how long the totality will last. Set an alarm on your phone for that time minus ten or fifteen seconds. As the eclipse reaches totality, wait until you cannot see the sun at all through the eclipse glasses, and only then take them off and start your phone’s timer. When the timer goes off, put your glasses back on immediately. The most dangerous times to look at an eclipse are right before totality and right after.

How do solar eclipses contribute to our understanding of the universe and scientific research?

Solar eclipses have contributed to our understanding of astronomy and science in a number of ways. The first and most blatant way is that total solar eclipses are the only time that we can see the sun’s corona from the Earth. The corona is a colorful region of the sun’s atmosphere that is normally too faint to see next to the sun. When the moon completely blocks the light that comes directly from the sun, the corona becomes visible. The changes in the corona from year to year have given us a greater understanding of solar weather patterns.

Solar eclipses also played a strong role in the scientific revolution of the Renaissance. Astronomers of that time knew that eclipses occurred during particular periods of the year but were unable to predict their timing or location exactly. This imprecision in their predictions was one of the factors that led the German mathematician Johannes Kepler to study observations of the planets in greater detail and conclude that planetary orbits were not the perfect circles that everyone had previously thought.

Solar eclipses also played a role in testing Einstein’s theory of relativity. One prediction of general relativity is that light bends when it passes near a massive object. We could therefore observe a star that is visually very close to our sun to see if its apparent position shifts. However, the sun is much brighter than any other star that we could use to test this theory, so we could only do so during a solar eclipse. In a strange twist of fate, Einstein’s original prediction was off due to a math error, but bad weather at the eclipse sites prevented any tests of the prediction until after he discovered and corrected that error.

Dr. Lawrence Camarota graduated with a B.S. in physics and a B.S. in aerospace engineering from the University of Florida. He earned a Ph.D. in physics with a focus on astronomy from the University of Arizona. He is a member of the American Association of Physics Teachers, the Royal Astronomical Society, and the Friends Society. His areas of interest are astrophysics, cosmology, electronics, and wavelets.