A solar eclipse occurs when the Moon passes between the Sun and the Earth so that the Sun is wholly or partially obscured. In ancient times, and in some cultures today, solar eclipses have been attributed to supernatural causes. Total solar eclipses can be frightening for people who are unaware of their astronomical explanation, as the Sun seems to disappear in the middle of the day and the sky darkens in a matter of minutes.

T y p e s Total Eclipse Annular Eclipse Hybrid Eclipse Partial Eclipse

The umbra, penumbra and antumbra are the names given to the three distinct parts of a shadow which are created when the source of light is not a point source. These names are usually used when referring to the shadows cast by celestial bodies. The umbra is the darkest part of a shadow. The penumbra is the region in which only a portion of the occulting body is obscuring the light source. The antumbra is the region from which the occulting body appears entirely contained within the disc of the light source.

Near the beginning and end of total solar eclipse, the thin slice of the Sun visible appears broken up into beads of light. These lights are called 'Baily's Beads' after the British astronomer Francis Baily who discovered them. They occur because the edge of the Moon is not smooth but jagged with mountain peaks. When just one bead is visible, the effect is often likened to a diamond ring.

By Kate McCarthy