A total solar eclipse visible from mainland United States takes place on August 21, 2017. On this occasion, the narrow band of totality will first hit land shortly after 10:15 am local time in Oregon. It then crosses through the states of Idaho, Wyoming, Montana, Iowa, Kansas, Nebraska, Missouri, Illinois, Kentucky, Tennessee, Georgia, North Carolina and South Carolina before moving into the Atlantic Ocean. Residents of cities and towns including Salem, Casper, Lincoln, Kansas City, St. Louis, Hopkinsville, Nashville, Columbia and Charleston will experience about a couple of minutes of totality. A partial eclipse is visible from all 50 US states, the width of Canada, Central America, Mexico, the Caribbean islands, northwest Europe and the Chukchi Peninsula in Russia.
A total solar eclipse occurs when the Moon passes directly between the Earth and the Sun, obscuring the Sun's disk as seen from the ground. Total eclipses are only possible due to a large slice of nature's luck. By sheer coincidence the Sun is about 400 times larger than the Moon, but also 400 times more distance. Therefore, both objects appear about the same size in the sky. However, it should be noted that the apparent sizes of the Sun and Moon do show small variations, and at times the Moon appears slightly larger than the Sun and vice-versa. A total solar eclipse occurs when the Moon's apparent diameter is large enough to completely cover the Sun's disk. All direct sunlight is then blocked, temporarily turning day into night.
The path of totality occurs inside a narrow band that has a maximum width of only 267 kilometres (167 miles). On the other hand, a partial solar eclipse can be seen over a region spanning many thousands of kilometres. The diagrams below show the visibility of this eclipse and the path of totality (Moons umbral shadow). Nashville will experience 1 minute and 56 seconds of totality, Lincoln City 1 minute and 53 seconds and Charleston 2 minutes and 4 seconds. The longest duration of totality will be 2 minutes and 41.6 seconds in Giant City State Park, just south of Carbondale, Illinois. Weather permitting, this could easily become the most viewed solar eclipse in history.