The Science of Totality

Abstract

An eclipse is the phenomenon in which a celestial body disappears or partially disappears behind another body or into the shadow of another body. This could be the Moon moving between the Earth and the Sun, referred to as a solar eclipse; or the Earth moving between the Sun and the Moon, referred to as a lunar eclipse. In an average year, there are two lunar eclipses and two solar eclipses. Over a long period, solar eclipses outnumber lunar eclipses in a ratio of about 5:3. However, from any one location on Earth, lunar eclipses can be seen more frequently. This is because they can usually be seen from more than a complete hemisphere of the Earth. In contrast, a solar eclipse is only visible from a much smaller area of the Earth, along the path of totality.