Driftless Dark Skies: The Great American Eclipse of 2017

February 7th, 2017 by John Heasley

On August 21, the sky will darken and the planets and stars will be visible in the middle of the day as our moon covers our sun.  This is a relatively rare event.  The last time a total solar eclipse was visible in the continental United States was 1979.  You won’t see another in the United States until 2024.  I have watched a handful of partial eclipses, but like most us, I have never experienced the awesome sight of the sun disappearing with only its corona visible.  From the stories I’ve heard, we don’t want to miss it. 

This one is all about alignment.  The moon’s path takes it near the sun every month, but it’s usually a little high or a little low to eclipse the sun.  This August, sun and moon and Earth are all aligned.  There’s also the wonderful coincidence of the moon and sun appearing the same size when viewed from Earth.  The moon is 400 hundred times smaller than the sun, but it is also 400 times closer—just the perfect size.  On average, there’s a solar eclipse somewhere on the planet every 18 months, but they are often over remote locations.  This one is just a day’s drive away. 

I love how astronomical events are a wonderful mix of the random and the predictable.  We can never know precisely when auroras or meteors might appear.  We do know that on the third Monday of August 2017, the moon’s shadow will cross the United States in just 93 minutes starting on the Pacific coast of Oregon at 10:16 am (PDT) and ending on the Atlantic coast of South Carolina at 2:49 pm (EDT).  The last time an eclipse crossed the United States from coast to coast was 1918.  Anyone along the 60-mile-wide path will be awed by the moon blotting out the sun and two minutes of totality. 

You need to be aligned with that path to experience totality.  If you stay in the Driftless Area, you will experience a 90% partial eclipse but not 90% of the awesomeness of a total eclipse.  Totality is as close as southern Illinois or Missouri.  If you wait for a total solar eclipse to come to Wisconsin, you will be waiting until 2099.  Many motels and campgrounds along the path are already booked, but there are still places available in easy range near the path.  It’s hard to predict how much excitement or traffic there will be as tens of millions of Americans travel to see the sight.  Stay flexible as the weather forecasts become clearer and be willing to relocate.  So plan ahead and don’t miss it. More in future blogs on what you’ll see and how to enjoy it safely. 

While you are waiting for the New Moon to eclipse the Sun, you can enjoy the Full Moon being dimmed a bit by Earth’s shadow during a penumbral lunar eclipse.  Join us at Kickapoo Valley Reserve on Friday February 10 (5-7pm) when we walk by Light of the Full Snow Moon.  Attendees will gather at the Visitor Center and hike down to Old 131 Trail. KVR astronomy educators will have binoculars and a telescope for you to see the maria, craters, and rays of the Full Moon.  We will also look at planets and constellations while enjoying the other sights, sounds, and smells of the moonlit world. Involves moderate hiking in the dark on uneven and possibly slippery surfaces. Participants have the option of remaining at the Visitor Center for stargazing. Please register to receive weather updates. Annual or day trail pass required. Call the KVR Visitor Center to register 608-625-2960. 

John Heasley is an astronomy educator and stargazer who enjoys connecting people with the cosmos. He volunteers with NASA/JPL as a Solar System Ambassador. For more information about stargazing in southwest WI, like Driftless Stargazing LLC on Facebook and find out whenever there’s something awesome happening in the skies. Driftless Dark Skies appears monthly in the Voice of the River Valley.