A Rhyming Guide to Eclipse Science

Have you ever seen a solar eclipse? A new book for readers of all ages explains the science behind the rare and wonderful event.

Although solar eclipses happen somewhere on Earth almost every year, it’s rare to see an eclipse where you live. So, when tens of millions of people came out to view the 2017 total solar eclipse, the first in the United States in nearly four decades, they were treated to a special experience. More eclipses over the U.S. are coming up: an annular (or “ring-shaped”) eclipse in October 2023 and a total solar eclipse in April 2024.

Appearing in plenty of time to help kids, grown-ups, and school districts learn about and anticipate the eclipses is Totality!: An Eclipse Guide in Rhyme and Science. Written by an astrophysicist, it’s an engaging explanation of eclipse science in rhyme, sidebars, and graphics. The book includes a glossary and activities, and a free app that maps eclipses is also available. Totality! has been selected for “Story Time in Space” from the International Space Station, but readers of all ages can also find it on planet Earth and the internet.

This map shows the paths along which two upcoming eclipses will occur in the United States: the annular solar eclipse on Oct. 14, 2023, and the total solar eclipse on April 8, 2024.

The Moon’s varying distance from Earth affects solar eclipses. When the Moon is relatively close to Earth, we can get a total solar eclipse. When the Moon is relatively far, we get an annular eclipse. In either case, a partial solar eclipse occurs in regions touched by the Moon’s partial shadow.

The shadow is round, and not very wide. Along a thin path, it rapidly glides.

The Moon’s round shadow over the eastern United States during the 2017 total solar eclipse. The visible shadow includes all of the Moon’s full shadow and the darker part of its partial shadow.

The Moon is round, so both its full and partial shadows are also round. The sizes of the shadows during a particular eclipse depend on the Moon’s distance from Earth at the time. The full shadow never covers a region more than about 270 kilometers (167 miles) across and usually is much smaller (and sometimes does not even reach the Earth). The partial shadow is much larger (more than 6,000 kilometers across), which is why there is a partial solar eclipse in a wide region around the path of totality.

The shadows do not stay in one place, both because Earth rotates underneath them and because the Moon is moving in its orbit. Together, these motions cause the shadows to race across the Earth’s surface at a typical speed near 1,600 kilometers per hour (1,000 miles per hour). That is why totality does not last more than a few minutes in any one place.

This excerpt from Totality!: An Eclipse Guide in Rhyme and Science (2022) by Jeffrey Bennet appears with permission of Big Kid Science, a publisher that devotes 100% of its revenue to nonprofits, free curriculum, and educational outreach.

Dr. Jeffrey Bennett is a Colorado-based educator and has long specialized in math and science education. “Totality!” is his seventh book for children, and it will join his six previous children’s books as a selection for the Story Time From Space program, in which astronauts aboard the International Space Station read books to the children of Earth, with videos posted at storytimefromspace.com.