On August 21, 2017, the Moon's shadow will cross the continental U.S. for the first time since 1979 – and the first time it's traveled coast-to-coast since 1918. This total solar eclipse, whose path goes through 13 states, promises to be among the most widely observed in history. It's already the most widely anticipated, as many hotels within the path of totality sold out two years in advance. This presentation by Sky & Telescope senior editor Kelly Beatty provides an overview of the nature of solar eclipses, important past ones in U.S. history, and helpful advice for seeing next year's event successfully. Original music by Mark C. Petersen, Loch Ness Productions. Used with permission. Animations used under Creative Commons Attribution 4.0 International License.