Prepare yourself for the cows coming home early, chickens roosting, and a renewed search for the lost planet, Vulcan. These are just a handful of
historical snippets from colorful past events that have
surrounded a total solar eclipse blackout. On Monday,
August 21, 2017, millions of Americans will need to have
their eyes safely glued to the ground!
Not since 1918 — when a total solar eclipse swept
across the United States spanning from Washington to
Florida — have the residents of the US been able to
witness such a visual treat. In fact, according to NASA,
“everyone in North American will be able to experience
Coupling the moon’s elevation data obtained from the
NASA Lunar Reconnaissance Orbiter (LRO) with NASA’s
detailed earth topography maps has enabled anyone and
everyone to have the most detailed and precise maps ever
created for predicting all of the eclipse data along the path
of totality (see Figure 1).
In order to create such precise predictions, Ernie
Wright of NASA Goddard Space Flight Center in
Greenbelt, MD used LRO-generated elevation maps for
accurately showing the continuously varying lunar profile.
He then combined this lunar data with earthly terrestrial
elevation maps for an accurate observer sighting
“We couldn’t have done visualizations like this even
10 years ago,” Wright said. “This is a confluence of
increasing computing power and new datasets from
remote sensing platforms like LRO and the Shuttle Radar
Wright was also able to accurately illustrate the shape
of the moon’s umbra as it races across the topography
here on earth. Gone are the days of the umbra being
represented as a clean disc-like shape. Wright’s new NASA
lunar umbra is an irregular polygon featuring slightly
curved edges (see Figure 2).
Make a Pinhole Solar
In the areas of totality, you can expect a central
duration of approximately two minutes and 40 seconds. If
you’d like to visually experience this celestial spectacle,
August 2017 21
Post comments on this article and find any associated files and/or downloads at
Eclipse map/figure/table/predictions courtesy of Fred
Espenak, Emeritus, NASA/Goddard Space Flight
Center, from eclipse.gsfc.nasa.gov.
■ FIGURE 1. This unique map shows the path of the moon’s umbral shadow in which the sun will be completely
obscured by the moon during the total solar eclipse happening August 21, 2017, as well as the fraction of the
sun’s area covered by the moon outside the path of totality. The lunar shadow enters the US near Lincoln City,
OR at 9:05 a.m. PDT. Totality begins in the US in Lincoln City, OR at 10: 16 a.m. PDT. The total eclipse will end in
Charleston, SC at 2: 48 p.m. EDT. The lunar shadow leaves the US at 4:09 p.m. EDT. A partial eclipse will be
visible throughout the United States. Credit: NASA/Goddard/SVS/Ernie Wright.