Solar eclipses occur when Earth, the moon, and the sun are aligned so that—as seen from Earth—the moon appears to cover all or part of the sun's disk.

A given year may see up to three different kinds of solar eclipses. During a total eclipse, the moon completely blots out the sun, casting its dark central shadow, called the umbra, onto a very narrow strip along Earth's surface. (See pictures of the most recent total solar eclipse, over Easter Island.)

An annular eclipse happens when the moon covers only the central part of the sun's disk, leaving a ring of sunlight still visible. And partial solar eclipses happen when Earth