An Extraordinary Eclipse

Millions of people across the country watched the solar eclipse on Monday, August 21. The moon passed between Earth and the sun. Some observers saw the sun partly blocked by the moon. Lucky viewers in a narrow path across the country got to watch as the sun completely disappeared behind the moon.

At Scholastic’s offices in New York City, editors from the science and math magazines dashed outside to join the crowds that had gathered on street corners to watch the sky. We brought along special eclipse glasses and a pinhole projector to view the eclipse safely.

Scientists were excited for the eclipse too. For them, it wasn’t just a cool event to watch. It was also an unusual opportunity to study the sun and its effects on the Earth.

When the moon blocks the sun’s disk, the sun’s wispy outer layer called the corona comes into view. The corona isn’t as bright as the rest of the sun, so it’s usually invisible.

Many scientists took advantage of the eclipse to study the corona. Some wanted to see how the sun’s magnetic field affects it. Others were looking at the corona’s temperature and at different types of light that it gives off.

One research team studied the corona during the eclipse from a special plane carrying scientific instruments. The plane flew from Missouri to Tennessee. Flying along part of the eclipse’s path allowed the scientists to observe the corona for a longer time than viewers on the ground.

Other scientists were interested in the effects of the eclipse here on Earth. For example, the sun’s disappearance may cause changes in Earth’s atmosphere, the envelope of gases that surrounds our planet.

One experiment flew small unpiloted aircraft called drones into the shadow of the moon. The drones gathered data on how the eclipse affected temperature, humidity (the amount of moisture in the air), pressure (the force of air pushing down from above), and wind speed.

Some scientists looked for changes in animal behavior during the eclipse. Would horses get frisky like they often do in the evening? Would bees become less active as the air cooled?

There is evidence from past eclipses that animals notice and respond. For example, during a 2001 eclipse, scientists observed that some birds went quiet as the sun disappeared and then sang like they typically do at dawn when the sun reappeared. And during a 1963 eclipse over the ocean, tiny sea creatures displayed behaviors normally seen at night.

Scientists who studied this week’s eclipse will be analyzing their data over the coming months. As for those of us in the U.S. who can’t wait for the next chance to see a solar eclipse and all of the changes it brings: Mark your calendars for April 8, 2024.

Read more about the eclipse and analyze data about its path in our May 8, 2017 issue.