How Do You Tell the Difference Between Total, Annular, Solar, and Lunar Eclipses?
Traditionally, eclipses areِ divided intoِ two major types: solar andِ lunar.
Solar eclipses occur whenِ theِ Moon passes betweenِ Earth andِ the Sun, leaving a moving region ofِ shadow onِ Earth’s surface.
Lunar eclipses occur whenِ Earth passes betweenِ the Sun andِ the Moon, casting a shadow onِ the Moon.
Solar eclipses mayِ beِ classified asِ either total, inِ which theِ Moon completely covers theِ Sun, orِ annular, inِ which theِ Moon obscures allِ but anِ outer ring ofِ the Sun.
Whether anِ eclipse isِ total orِ annular depends onِ the distance betweenِ these threeِ objects.
Earth travels inِ anِ elliptical orbit aroundِ the Sun, andِ the Moon travels inِ anِ elliptical orbit aroundِ Earth, soِ the distance betweenِ these celestial bodies changes.
There areِ no annular lunar eclipses becauseِ Earth isِ much bigger thanِ the Moon, andِ its shadow willِ neverِ beِ small enoughِ to leave a ring.
However, theِ Moon doesِ experience total eclipses.
If theِ eclipse isِ a total lunar eclipse, theِ Moon willِ pass throughِ theِ umbra (area ofِ total shadow) created byِ Earth overِ the courseِ of aboutِ two hours.
Both solar andِ lunar eclipses mayِ alsoِ occur asِ partial eclipses.
A partial eclipse mayِ beِ seen byِ viewers whoِ stand outsideِ ofِ the region ofِ shadow created byِ the umbra—the path ofِ totality—but whoِ remain withinِ theِ large region ofِ shadow covered byِ the penumbra, a region ofِ lesser shadow whereِ someِ light stillِ penetrates.
A partial eclipse ofِ the Sun alsoِ results whenِ theِ Moon’s penumbra falls onِ Earth butِ its umbra doesِ not.
Total solar eclipses takeِ place somewhereِ onِ the planet aboutِ every 18 months orِ so, butِ the average frequency ofِ the event forِ anyِ random point onِ the planet isِ roughly onceِ inِ almost 400 years.
Across theِ planet, however, solar eclipses areِ actuallyِ more frequent thanِ lunar ones.
Nevertheless, sinceِ solar eclipses canِ beِ seen fromِ only a veryِ limited region ofِ Earth atِ a time andِ lunar eclipses canِ beِ seen byِ anِ entire hemisphere, solar eclipses mayِ seem lessِ frequent.