Types of Solar Eclipses
Eclipses of the Sun come in four different flavors. There’s the relatively common partial eclipse, and the extremely rare hybrid. In between, in terms of frequency of occurrence, are the much-sought-after total and annular solar eclipses. For many people, watching the Sun vanish from the sky during a total eclipse of the Sun is a very emotional experience.
An annular solar eclipse sometimes evokes less emotion, as the Sun never entirely disappears from view: the edge remains visible, known commonly as the “Ring Of Fire”.
Hybrid solar eclipses are unusual and very infrequent. A partial solar eclipse accompanies all total, annular, and hybrid eclipses, but it also occurs by itself. Here’s what you need to know about these four solar eclipse variants.
What is a Solar Eclipse?
Simply put, a solar eclipse happens when the Moon covers at least a tiny fraction of the Sun’s surface. For this to occur, the Sun, Moon, and Earth must be aligned, which means a solar eclipse can take place only during a new Moon phase. The type of eclipse we see depends on how good the alignment is and whether the Sun and Moon are the same apparent size in the sky.
Although the Sun is 400 larger than the Moon, it’s also 400 times farther away. So on average, both appear to have the same apparent diameter—they look to be the same size. But slight variations in the Moon’s orbit around Earth, and in Earth’s orbit around the Sun, mean that the apparent size of the Sun and Moon are not always equal.
If the Sun-Moon-Earth alignment is perfect, and the apparent size of the Moon is slightly larger than the Sun’s, then a total solar eclipse occurs. If the alignment is perfect, but the Moon’s apparent size is slightly smaller than the Sun’s, the result is an annular solar eclipse. A hybrid eclipse happens when the eclipse changes from annular to total (or vice versa) along the eclipse path.
If you happen to be on the centerline path of one of these three eclipse types, you’ll also experience partial eclipses before and after the ‘main event.’ But if the alignment is not perfect, a partial eclipse is the only outcome, because the Moon covers only part of the Sun’s surface.
Solar eclipses of any type happen two to five times a year. They occur in any combination of partials, annulars, totals, or hybrids, with one exception—it’s not possible to have two total eclipses back to back. There are always at least two solar eclipses per year; five in any one year is possible, but extremely rare. Over a 5,000 year period, the occurrence of three of the four solar eclipse types is quite even: 35% are stand-along partials, 33% annulars, and 27% totals. To emphasize their rarity, less than 5% of all solar eclipses are hybrid.