Residents of the United States will have the unique opportunity to observe a total eclipse of the sun on August 21, 2017. A total eclipse of the sun means that the moon blocks out the sun entirely for a matter of moments while it makes its way across the sky.
The eclipse will be like most others, where the moon passes in front of the sun and temporarily obscures the majority of the sun’s light from making it to the Earth. The day will seem to darken into twilight and dusk, and some residents may be able to see a few stars appear in the sky. Total eclipses happen approximately every 17.6 months, or roughly 68 in a century.
A total eclipse means that the moon’s conical shadow, or umbra, is cast onto the Earth’s surface. This umbra can be very long, but narrow. This means that the total eclipse, or the surface of the sun being completely covered by the moon, is only visible from specific places. Some places where total eclipses have been viewed from include Nunavut, Canada in 2008, Easter Island in 2010 and Svalbard, Norway in 2015.
For the first time since 1979 a total solar eclipse will be visible from the contiguous United States, and the moon’s shadow track will only be visible in the United States. This solar eclipse is being called “The Great American Eclipse” for this very reason. Residents of the lower 48 states will have the unique opportunity to spot the eclipse from their homes, and the 12 million residents who live in the path of totality (or the shadow track) will be able to observe the total eclipse right from their backyards.
The next total solar eclipse will be in April of 2024, and only some locations will be in the right place to view the event. The last major solar eclipse that was visible to many Americans was in 1979, but the best viewing of this eclipse was in the Northern Plains and the Pacific Northwest.
The path of the total solar eclipse will begin in the North Pacific Ocean northwest of Hawaii. The shadow of the eclipse will hit the West Coast of the United States in Oregon and proceed from there into Idaho, Wyoming, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina and, finally, South Carolina. The shadow of the solar eclipse will be about 67 miles wide, or 108 kilometers. At its widest the shadow will be 71 miles, or 114 kilometers wide.
The solar eclipse’s totality will be the best along the center of the shadow’s path. Everyone in the United States will catch a glimpse of the penumbra, or partial eclipse. The eclipse will only be visible for a few minutes because of the speed of the Earth, sun, and moon’s movements.
- NASA’s Interactive map of the path of the Total Solar Eclipse of 2017 Aug 21
- Total Eclipse of the Sun Visible from the USA – Information page from NASA
- GreatAmericanEclipse.com – web site with a range of information about the eclipse.
- The Great American Total Solar Eclipse Is Coming 2 Years from Today. Space.com, August 17, 2015.