The Backyard Astronomer by Adam England
What do you call it when
the Moon is directly between the Earth and the Sun? — a solar eclipse.
the Earth is directly between the Moon and the Sun? — a lunar eclipse.
the Sun is directly between the Earth and the Moon? — an apocalypse!
The word ‘eclipse’ stems from the Greek ekleipsis, meaning, “failure to appear.” Between two and five times each year the Sun fails to appear, either partially or in full, due to the orbital mechanics of Earth, Sun and Moon. As the Earth swings around the Sun and the Moon spins around the Earth, their orbits periodically line up to where they are on a direct line, causing the Moon’s shadow to cover a small portion of the Earth’s surface.
“Small” is a relative term here, as we experienced on August 21, 2017, when the shadow of the Moon traversed from the Pacific northwest to the southeast United States. Where the shadow completely blocks out light from the sun, we call it ‘totality.’ While the path of totality in 2017 covered thousands of miles and amazed millions of onlookers, we know that the Earth’s surface is mostly uninhabited, covered by dense forest, vast desert, frozen tundra or open ocean. So many eclipses go unseen, able to cross thousands of miles of the Pacific Ocean with few if any human viewers.
Eclipse-chasers from around the world reserve hotels and campsites years in advance to get views of these rare events.
In central Yavapai County we were able to observe a partial eclipse in 2017, with the Moon covering at most 76% of the Sun. Sometimes we see partial eclipses where the Moon is slightly farther from Earth in its orbit, causing it to block out the center of the Sun, leaving a ring of light around the Moon. This is called an annular eclipse, such as that seen at the Grand Canyon on May 20, 2012. Also called a Ring of Fire eclipse, these events make for great images, but only with the proper equipment — even the small ring of light radiating from the Sun can damage your eyes. The next annular eclipse visible in our area will come on October 14, 2023.
Just a few months later, a total solar eclipse will once again grace the skies of North America on April 8, 2024. The path of totality will cross Mexico and Texas, continuing over much of the Midwest and almost directly over Indianapolis and Buffalo, then on to northern Maine.
Should you want to travel for a view of totality, book your reservations now! Eclipse-chasers from around the world reserve hotels and campsites years in advance to get views of these rare events. If you don’t intend to travel, mark your calendar to keep an eye out for local events to celebrate with amateur astronomers and skywatchers locally.
To learn more about the sky, telescopes, or socialize with other amateur astronomers, visit us at prescottastronomyclub.org or Facebook @PrescottAstronomyClub to find the next star party, StarTalk or event.
Adam England is the owner of Manzanita Financial and moonlights as an amateur astronomer, writer, and interplanetary conquest consultant. Follow his rants and exploits on Twitter@AZSalesman or Facebook.com/insuredbyadam.