In a solar eclipse, the Moon moves between the Earth and the Sun. When this happens, part of the Sun's light is blocked. The sky slowly gets dark as the Moon moves in front of the Sun. When the Moon and Sun are in a perfect line, it is called a total eclipse. These are very rare. Most people only see one in their lifetime.As the Moon passes between the Sun and the Earth, the Moon begins to block out some of the Sun's light casting a shadow on the Earth. A small "bite" appears on the western edge of the Sun. The Moon continues to move in front of the Sun, until only a small crescent of light can be seen. The sky begins to darken as the crescent of the Sun remains in the sky. Thin wavy lines called Shadow Bands appear on plain surfaces on the ground. Shadow Bands are caused by the irregularities in the Earth's atmosphere. As the crescent disappears, tiny specks of light are visible around the edge of the Sun. These specks of light are called Baily's Beads and are the last rays of sunlight shining through the valleys on the edge of the Moon. Suddenly the sky is dark, but if you look toward the horizon you will see a reddish glow which looks like a sunset. Once the Sun is totally eclipsed, the Sun's corona can be seen shining in all directions around the Moon. This is a spectacular sight because the only time the Sun's corona can be seen is during a total solar eclipse. Also visible during a total solar eclipse are colorful lights from the Sun's chromosphere and solar prominences shooting out through the Sun's atmosphere. When the total eclipse of the Sun is completed, the shadow of the Moon passes and sunlight appears once again at the western edge of the Sun. The corona disappears, Baily's Beads appear for a few seconds, and then a thin crescent of the Sun becomes visible. Daylight returns and the Moon continues to orbit the Earth. The total solar eclipse is over.
The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/ GSFC.
StarChild Authors: The StarChild Team
StarChild Graphics & Music: Acknowledgments
StarChild Project Leader: Dr. Laura A. Whitlock
Responsible NASA Official: