I’m so happy and honored to be sharing with you all this special guest post, written by my dear friend, Julie Sacco. Today Julie is sharing with us the science behind the last recent eclipse of 2017 and her own observations as a Chicagoan.
WHAT ON EARTH?
A occasional piece considering issues in the natural world that interface with people’s lives, in the hope that readers think globally and act locally for the betterment of biodiversity and their fellow occupants of Planet Earth. It’s probably better than the alternative.
The Solar Eclipse of August 21, 2017: A Chicagoan’s Observations.
The numbers are astronomical:
A flaming sphere 94 million miles away crossed celestial paths with a pock-marked rock 239,000 miles away causing a 68-mile wide shadow to sweep 3,000 miles from the west coast of Oregon to the east coast of South Carolina creating a path of totality through 10 states in 3 hours and 3 minutes … but who’s counting.
Thanks to a celestial coincidence, a total eclipse occurs every 18 months during a new moon. While the sun is 400 times larger than the moon, the moon is 400 times closer to the earth, making both appear to be the same size. When these three spheres are precisely aligned in syzygy, so that the moon passes directly in front of the sun from the earth’s perspective, the sun is obscured resulting in a total eclipse.
On Monday, August 21, 2017 at 1:19 pm, the midpoint of the moon’s umbra spilled over the banks of the Mississippi River to enter Illinois; 5 minutes later, at 1:24 pm, it swept past the Ohio River into Kentucky. And so it progressed, until flying over the Atlantic Ocean at 2:40 pm. Traveling at 2,400 mph, this transcontinental air show was over in 183 minutes. It was the first solar eclipse visible from the United States since 1979, and the first to traverse the continental U.S. in 99 years.
Now you see it, now you don’t
For millennia, a solar eclipse was suffered with dread and explained by myths. It was everything from a hungry dragon above China lunching on the solar globe, to Great Plains Indians’ belief that the sun and moon merged as if in marriage. In a real game of thrones, Babylonian kings briefly abdicated and crowned a temporary monarch until royal soothsayers declared it safe to dethrone, and then decapitate, the avatar. But not all superstitions were bloody: the Italians believed that flowers planted during a solar eclipse grew more colorful and more vibrant than all others.
The stars dictate, and physics confirms, that the next total solar eclipse visible within the Lower 48 will be on April 8, 2024, taking a southwest-to-northeast trajectory through 14 states, from Texas to Maine. And while the 2017 maximum totality was 2 minutes and 40.2 seconds, totality in 2024 will last 3 minutes and 22 seconds. The longest duration possible is 7 minutes and 32 seconds.
Birds gotta swim and fish gotta fly
For all the myths surrounding a solar eclipse, some unusual things actually do happen in nature. Flowers react to the lack of sunlight by folding up their petals. Birds stop singing and wing to their evening homes – except for owls who get an encore performance that day. Ants are dazed and confused scurrying for their mounds, and salmon wash ashore looking for food in the darkened water.
How important was it to the ancients to learn the mysteries of an eclipse? In 1999, it was discovered that spiral-shaped petroglyphs in Ireland correspond to a solar eclipse on November 30, 3340 BC. Fast-forward to 2145 BC when Chinese emperor Chung K’ang executed two court astronomers for not predicting an eclipse in-progress.
But it was the detailed records kept by Babylonian and Assyrian observers between 1700-763 BC that made it possible for later sky gazers to predict eclipses 25,000 years into the future. In AD 150, Claudius Ptolemy successfully did the math, geometry and trigonometry, that allowed for accurate calculations. This was the turning point from superstition to science: no more hungry dragons or cranky gods messing with mere mortals, an eclipse was merely a calculable event involving the orbits of the moon, the earth and the sun. Mystery solved.
Tickling Tom’s fancy
Which is not to say that an eclipse can’t be a hoot. Chicago’s homegrown weather wonk, Tom Skilling, was in downstate Carbondale, Illinois, covering the event. As if sprinkled with pixie dust when the eclipse reached totality at 1:20:06 pm, Skilling spent the next 2 minutes and 37 seconds giggling incomprehensibly. Thousands of fellow enrapt observers swayed while singing “Here comes the sun.” Was this Carbondale or Stonehenge?
I’m being followed by a moon shadow
All this fuss for what? Playing peek-a-boo with Old Sol? “Liking” the eclipse on Facebook along with 160 million others? Cobbling together a pinhole viewing box? Fretting over defective Amazon sunglasses? Why, there wasn’t even enough darkness to trick a cricket into chirping.
Chicago pulled the short straw called overcast skies on August 21. Adding insult to injury, The Windy City sits at a 6 degree Latitude and a 1 degree Longitude difference from Carbondale. This geographical skew meant that Chicago was swiped by 87% penumbra coverage vs. the coveted 100% corona exposure. Notwithstanding, this lady went gaga when day turned into, well, late afternoon.
A solstice provides us with an opportunity to do some personal reflection, to think how wide a shadow we cast on everything around us. Like much of what we experience in life, a solstice can be at once surprising yet predictable; irrefutable yet unbelievable; revealing yet concealing; fun yet frightening. As long as people have pondered the universe and life within it, we’ve lived with a bifurcation between what is and what should be, a dichotomy that splits what we want from what we need. This duality drives our decision-making and creates the consequences that ripple throughout the universe.
Everything I need to know I learned from an eclipse
Don’t think so? Try this at home – or maybe don’t: overshadow a loved one and experience real darkness; insist on being right at the expense of someone’s feelings and watch your righteous correctness corrode a relationship; turn a blind eye to another’s needs and see the world through jaundiced-colored glasses; smother somebody else’s aspirations and feel two worlds implode; criticize someone dear in order to improve them and a bond unravels.
Flip your world on its axis and do the opposite: enable everyone to shine like the heavenly body they were created to be; give someone the benefit of the doubt and galvanize a relationship; put others’ needs before your own and nurture their world; enkindle somebody’s dreams and expand their universe; temper criticism with love and kindness so that it’s constructive.
Chicago’s most recent total solar eclipse was on June 6, 1806; its next will be on July 17, 2205. That’s a gap of 399.1 years. What will you do with your time, imagination, passion and joy until the next eclipse hurdles your way?