Total solar eclipses are rare at any particular location because totality exists only along a narrow path on the Earth's surface traced by the Moon's full shadow or umbra. An eclipse is a natural phenomenon.

How does a total solar eclipse happen?

A TOTAL ECLIPSE happens when the moon completely covers the sun. Here, the observer is standing under the umbral shadow of the moon. In a total solar eclipse, the sun's outer atmosphere can be seen. The brighter stars and the planets come out.

When was the last total solar eclipse?

A total solar eclipse — like the one that crossed the U.S. on Aug. 21, 2017 — occurs when the moon blocks 100% of the solar disk. If an observer is standing within the path of totality, they will notice a 360-degree sunset and see just the outermost layer of the sun, called the corona, during the total eclipse's peak.