By Dr. Ed Albin
Program Director, Space Studies, American Public University
For millions of Americans, Monday, August 21, 2017, will present a rare opportunity to see a spectacular total eclipse of the sun. The swath of totality will make a diagonal path across the United States, from Oregon to South Carolina.
Although totality will last only two and a half minutes at most, it’s worth the effort to see the eclipse. People within its bicoastal path will see one of nature’s most fascinating spectacles.
Many members of the APUS Space Studies department will be traveling across the country from South Carolina to Georgia, Tennessee and Kentucky to view and photograph the eclipse.
As darkness falls during broad daylight, bright stars and planets will be visible against the briefly darkened sky. Birds and other animals may become confused by the sudden nightfall.
How Solar Eclipses Occur
One oddity of the Moon relative to our Sun is that the Moon is approximately 400 times smaller than the Sun. But the Sun just happens to be 400 times farther away from Earth than the Moon. This distance discrepancy means that both the Sun and the Moon have the same apparent size in the sky, allowing the Moon to exactly cover up the Sun and cause a total solar eclipse.
Furthermore, a solar eclipse occurs only when the Moon is in the New Moon phase, or when it is positioned precisely between the Earth and the Sun. However, since the Moon’s orbit is slightly tilted to Earth’s orbit, we do not have a solar eclipse every month at the New Moon.
It is only when the Moon is exactly lined up with the Sun that an eclipse occurs. This is what will happen on Monday.
If you want to see the eclipse’s path, NASA offers an interactive map.
Resources for Watching the Eclipse
If you cannot make it to a location along the path of totality or if it’s cloudy on Monday, you can watch the eclipse streamed live from this NASA website. You can also learn more about the upcoming eclipse by visiting the Sky & Telescope magazine eclipse page.
Observing the Eclipse
You can damage your eyesight – or even go blind – if you look directly at the Sun with the naked eye or through an unfiltered telescope. However, there are many safe and easy ways to see the eclipse.
You can build an inexpensive solar pinhole projection box by following the instructions on the Time and Date website.
Perhaps the simplest way to view the eclipse is to sit beneath a shade tree and watch as the leaves project a myriad of eclipse images onto the ground. The leaves act as natural tiny pinhole projectors, casting really cool crescents all around you.
If you visit your local planetarium or public observatory, you should be able to purchase special eclipse eyeglasses for a few dollars. Even better, these facilities may have an eclipse party planned, so the public can view this rare celestial event safely through filtered telescopes.
Let’s hope for clear weather on Monday, August 21st!
About the Author
Dr. Ed Albin is an Associate Professor and Program Director of Space Studies in the School of STEM (Science, Technology, Engineering and Math) at American Public University. His academic credentials include a Ph.D. in Planetary Geology from the University of Georgia, an M.S. in Planetary Science from Arizona State University and a B.S. in Earth Science from Columbus State University. Ed has also held positions as an assistant professor, a planetarium lecturer, a commercial helicopter pilot and a planetary geologist.