On August 21, 2017 the path of the first solar eclipses over the Unites States in 38 years traversed approximately 2,500 miles of the country from Newport, Oregon to McClellanville, South Carolina. Just outside Shoshoni, Wyoming, the path passed over Boysen Reservoir. At this location, totality lasted 2 minutes and 22 seconds, being at its maximum about 11:40 am. With the moon blocking the solar disk during totality, red flares called solar prominences become visible at the edge of the dark disk. The red-glowing looped material is plasma, a hot gas composed of electrically charged hydrogen and helium. These prominences look small in relation to the size of the sun, but typically extend over many thousands of kilometers with the largest on record being estimated at over 800,000 kilometres (500,000 miles). A prominence forms over timescales of about a day and may persist for several weeks or months.
During the total solar eclipse, the sun’s outer atmosphere called the corona becomes visible as it extends millions of miles into space. The corona consists of extremely hot ionized gases which exceed 1 million degrees Kelvin – 150- to 450-times hotter than the surface of the sun. Being over 1 million million times less dense and much hotter than the sun’s surface and the solar prominences, the corona actually produces about one-millionth as much visible light, thus becoming visible from earth typically only during a total solar eclipse. The sun’s magnetic fields bend the corona into its remarkable shapes.
In this image, 10 different photographic exposures of the solar eclipse were composited to show the eclipsing moon, solar prominences and the corona. The image was then manipulated by a process involving radial blur subtraction and image offset overlay to accentuate the pattern of the corona. The coloration of the eclipsing moon and the solar prominences were retained in this rendition. (exposure stack of 10 images)