Space and Solar System

An annular eclipse occurs when the Moon is at its farthest point in its orbit around Earth (called apogee), and the apparent diameter of the Moon is smaller than the apparent diameter of the Sun. As a result, the Moon cannot completely cover the Sun, and a ring of sunlight is visible around the Moon.

Eclipses occur when the Sun, Earth, and the Moon align in a straight or almost straight configuration. Astronomers call this a syzygy, from the ancient Greek word syzygia, meaning to be yoked together or conjoined.