Sunday, August 21, 2016

Make America Eclipse Again

 One year from now, Monday August 21, 2017, Americans will finally get  to experience one of Earth's most unique phenomenons that hasn't occurred since 1979: a total solar eclipse. The last total solar eclipse that crossed the continental United States occurred on February 26, 1979, but that eclipse covered mostly rural land and the weather was rainy. The last eclipse that actually crossed a sizable amount of eyeballs was in 1970. And the last eclipse to travel most of the United States? 1918. 
     The 2017 eclipse will cross the states of Oregon, Idaho, Wyoming, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, North Carolina, and South Carolina. States outside of this path will still get to catch a peek of the eclipse, but they unfortunately won't get the full show. The states and regions outside of the path will only get a partial eclipse. For instance, only 97 percent of the Sun will be covered in Atlanta, 81 percent in Washington, DC, 78 percent in Miami, 76 percent in Dallas, 72 percent in New York City, and a paltry 62 percent in Los Angeles. Better book your plane tickets to Missouri now!
      Before modern astronomy, eclipses were thought to be the signs of dread. The British saw eclipses as bad signs for the monarchy. In Vietnam it was thought that the Sun was being eaten by a giant frog. The Vikings blamed wolves. China blamed dragons. Latin America saw a jaguar. Eskimos feared sickness. Ethiopians scarified animals. The Greeks saw eclipses as a sign of impending calamity. Inuits saw eclipses as the Sun god and Moon god fighting. In India there was belief that the atmosphere was poisonous. Some cultures saw evil spirits and banged pots and pans or shot off fireworks to scare them away.
     Christopher Columbus (who did not discover America) even tricked the native Jamaicans, telling them the Sun wouldn't come back if they didn't give in to him. The Sun returned (note this was a lunar eclipse, not solar), and the natives were swayed. Even today, superstition surrounding eclipses still exists. Some Christian evangelists use eclipses as signs of approaching doomsday. Others believe that solar eclipses are dangerous to pregnant women. Rest assure, all of this is baseless. Eclipses are just apart of a cosmic 18-year cycle, called a saros. Nothing more, nothing less. Eclipses weren't alone as many cultures felt the same about comets as well.
     So other than the awful Twilight movie, what is an eclipse? Well a lunar eclipse is when the Earth aligns perfectly between the Sun and the moon, which makes the Earth's shadow cast on the moon. The Moon appears red thanks to "rayleigh scattering." Since the Earth is positioned between the Earth and the Sun, a lunar eclipse can only occur during a full moon. Unlike solar eclipses, lunar eclipses are able to be viewed anywhere on the night side of Earth, and last for hours.
     A solar eclipse is when the Moon aligns perfectly between the Sun and the Earth. Because of this, solar eclipses can only occur during a new moon. With a solar eclipse, the Moon casts a shadow on the Earth, called the umbra and the penumbra. There are three types of solar eclipses: total, partial, and annular. A total solar eclipse is when the Moon completely blocks out the Sun. Annular is when the Moon is to far to completely block out the Sun. An antumbra shadow is cast on the Earth. Partial is when the Sun and Moon don't perfectly align. There is a rare fourth kind called hybrid, which is when an annular eclipse turns into a total.
     So why aren't eclipses common? Well because the Moon's orbit isn't a perfect circle, and the Moon is not on the ecliptic plane (the imaginary path that the Sun travels on in the sky). If it was, we'd be blessed with solar eclipses every month. Unlike a lunar eclipse, looking directly at a solar eclipse is extremely dangerous and could essentially fry your eyes. Solar eclipses are also extremely short: the longest ever recorded lasting a little over 7 minutes. The maximum totality of the 2017 eclipse will only last 2 minutes and 40 seconds.
     So why will next year's eclipse only be totally visible from Oregon to South Carolina? Why can't Florida, Texas, California, New York, and Ohio get in on the fun? Well, it's because of the Moon. The Moon is small, which means the umbra, or shadow, will travel along a narrower path. Florida and company will still get to view the eclipse, but only partially.
     Wherever you plan on viewing the eclipse, do not forget to bring protective eye wear with you. While the eclipse is completely safe to look at during totality, when it is not in totality, it can be extremely harmful. Expect stocks of eclipse glasses at Walmart and Target pretty soon. I'm sure they're on Amazon now if you just can't wait.
     The 2017 eclipse is expected to become the most viewed eclipse ever. Even though Salem, OR, Columbia, SC, Greenville, SC, Nashville, TN, and Charleston, SC are the only major US cities/metros that lie directly in the path of totality, the major cities of Atlanta, Charlotte, Louisville, Portland, Saint Louis, Kansas City, Memphis, Topeka, Birmingham, Savannah, Denver, Boise, Seattle, Salt Lake City, Jacksonville, Des Moines, Cincinnati, Indianapolis, and Omaha will be within reasonable driving distance. While Kansas City and Saint Louis don't lie in the path, parts of their metro areas do. Media coverage will be plentiful, and most of North America, from Canada to the Caribbean, will get to view the eclipse in some form.
     So the countdown begins now. We have one year left. Take off work, book plane tickets, set your alarm, move your surgery date, skip class, whatever you have to do to make sure you don't miss this event. Here's an amazing time lapse of the 2015 solar eclipse as seen from an airplane. Here's a video of a lucky group of people who got to experience this year's total solar eclipse (which spent most of it's time over the uninhabited Pacific Ocean) from an airplane. In these videos the shadow of the moon is clearly visible. Warning: the voice of the "narrator" of the video is a just a tad distracting. Just a tad.

*Astronomy, Wikipedia, Smithsonian, Space, Derekscope, Emaze, NASA, USA Today, Arstechnica, International Business TImes, Greymeter, Citybus Express, Time and Date, Sky and Telescope

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