Elizabeth MacTavish, clinical assistant professor of STEM education in UT’s College of Education, Health, and Human Sciences
UT Professor Elizabeth MacTavish encourages parents to experience the upcoming total solar eclipse on Monday, Aug. 21, with their children. But how do parents explain one of nature’s most extraordinary events?
"Several school districts in our area are closing to allow students to experience this historic event,” said Ms. MacTavish, a former Knox County Schools science teacher and current clinical assistant professor in STEM education in UT’s College of Education, Health, and Human Sciences. “But I’ve had many parents express concern about being able to accurately explain the hows and whys of what’s happening. The good news is that many teachers are planning exciting ways to educate kids about the eclipse during the first few weeks of school.”
Most of East Tennessee will be in the eclipse’s path. Some in the region will even experience a total solar eclipse, resulting in complete darkness around 2:30 p.m.
Ms. MacTavish offers the following tips for parents:
Channel your inner science teacher. When your child asks, “What is a solar eclipse?” explain that a solar eclipse occurs when the moon is in the new moon phase and travels between Earth and the sun. As the moon moves between the sun and Earth, its shadow blocks either all of the sun’s light (a total eclipse) or some of the sun’s light (a partial eclipse) from reaching Earth’s surface.
A total solar eclipse lasts for hours from beginning to end, with the complete blockage of the sun (totality) lasting from a few minutes to only seconds depending on a person’s location. The closer to the path of totality, the more the moon will cover the sun.
Ms. MacTavish says basic math helps us understand how the moon is able to cover the sun even though the sun is so much larger.
“In Earth’s sky, the moon and the sun appear to be the same size," she said. "That’s because even though the sun’s diameter is 400 times greater than the moon, the moon is 400 times closer to Earth. So mathematically their distances from Earth cancel out their differences in size and they appear to be the same size from Earth. It’s like being able to block out someone’s head from across the room just by using your thumb.”
Respect the historic nature of this moment. Total solar eclipses occur somewhere on Earth about every 18 months, but because most of Earth is covered in water, those events are rarely over land and seldom witnessed. On average, a total solar eclipse is visible from any one place on Earth once every 375 years.
“It would take about a thousand years for every place in the continental United States to see a solar eclipse—plus the weather must cooperate too,” said Ms. MacTavish. “This total solar eclipse is a once-in-a-lifetime event.”
Know where to watch the eclipse. The good news is that anyone in North America will be able to enjoy at least a partial eclipse, but those within the small 70-mile wide ribbon of the totality path will enjoy a total solar eclipse. The totality path begins with the residents of Lincoln Beach, Oregon, at 10:16 a.m. PST and ends in Charleston, South Carolina, at 2:48 p.m. EDT. Over the course of 90 minutes, the eclipse will move across Oregon, Idaho, Wyoming, Montana, Nebraska, Iowa, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina, and South Carolina.
“Where you view the eclipse within the eclipse path will determine the degree to which you are able to witness totality,” said Ms. MacTavish. “My suggestion is to travel as close to the totality path as possible, but plan ahead as traffic and parking may be your biggest challenge.”
Expect the unexpected. Solar eclipses cause some unusual changes to our surroundings. Once the moon begins to cover the sun, Ms. MacTavish says to look for the following changes.
The lighting will begin to change as if nighttime is occurring in the middle of the day.
The temperature will drop as the warmth provided by the sun is blocked from reaching Earth.
Animals will be confused. Both wild and domesticated animals will display habits typically associated with nighttime routines.
Stars will appear. Although stars are always present in the sky, the sun is the only star visible during the day.
If you are able to witness totality, take a few seconds during that time to scan the horizon. While the sky may be dark, the horizon will resemble a perfect sunrise.
Wear eye protection. Looking directly at the sun can cause severe eye injury or blindness. It is critical to wear safety glasses during the eclipse.
“Fortunately, getting hold of eclipse glasses is very easy,” said Ms. MacTavish. “School systems, public libraries, museums, and even Amazon have eclipse glasses. Sunglasses are not safe to view the eclipse. The only time it is safe to remove eclipse glasses would be during the totality phase, when 100 percent of the sun’s light is blocked from Earth’s surface.”
Download a solar eclipse app. Ms. MacTavish recommends downloading an app called Solar Eclipse Timer, available through the AppStore or Google Play for $1.99. Created by solar eclipse expert Gordon Telepun, the app will announce the proper times for viewing partial phase phenomena and when it’s safe to remove eclipse eyewear.
“As long as you are within the solar eclipse path, this app will talk you through the eclipse,” she said. “It’s as if you have your own personal astronomer by your side.”
Elizabeth MacTavish’s children, Emma, 11, and Carson, 10, demonstrate how a thumb can block out someone’s head from across the street to show how the moon—although 400 times smaller than the sun—is able to block the sun during an eclipse.