About this print: This is a time-lapse image of the total solar eclipse over North America on August 21, 2017. A total solar eclipse occurs when the Moon moves in perfect line between the Earth and the Sun. In geographic regions where totality occurs, the Moon completely blocks the Sun so that only the solar corona can be seen. The solar corona is visible surrounding the three photos in the center of this image. Moments before and after totality another phenomenon is visible called Baily’s Beads. This phenomenon is caused by rays of sunlight streaming through craters and mountains on the Moon’s surface. These irregularities make it appear as if there is a string of pearls on one side of the Moon. If a photograph is captured at just the right moment when either the final or first Baily’s Bead before or after totality is visible, the total solar eclipse complex (the Sun and the Moon) appears as a “diamond ring in the sky,” visible in the center photo.