Have any plans for the morning of August 21? Many will be observing the "Great American Solar Eclipse," as the new Moon passes between our planet and its star, casting its shadow onto Earth's surface and causing a total solar eclipse. Not since 1979 has the path of a total eclipse touched American soil, and that time, it curved only over the northwest, passing over Washington, Oregon, Idaho, Montana, and North Dakota. This time, the shadow makes a long, diagonal slash across the country, starting in Oregon and moving into Idaho, crossing Wyoming, Nebraska and Missouri to parts of Kentucky, Tennessee, northern Georgia, and finally leaving the East Coast in South Carolina. As seen from along that narrow path, the Moon will completely block the Sun from view, allowing its softly-glowing outer atmosphere, or "corona," to be seen.
Observers in areas not located precisely on the path of totality will experience a partial eclipse, depending on how far they are from the shadow's path. As seen from San Francisco, the Moon will encroach across 80% of the Sun's disk, making the Sun look like a crescent. This crescent will still be bright enough to wash the corona from view, and Morrison Planetarium staff will be hosting safe observations with the public from the Academy and showing a live-stream of the eclipse from the Internet in case local skies are cloudy.