![]() With its brilliant disk completely covered, the Sun's ghostly white outer atmosphere is momentarily revealed for anywhere from seconds to several minutes. If the Moon completely hides the Sun, even for a moment, the eclipse is considered total. (But there's still an element of luck involved: December 2011's total lunar eclipse was gorgeous from Los Angeles but completely unobservable from New York.)įew events in nature offer the drama and spectacle of a total solar eclipse, as demonstrated by this one seen over China on August 1, 2008.īecause the Moon casts a smaller shadow than Earth does, eclipses of the Sun tightly constrain where you can see them. And if its disk passes just outside the umbra, it still encounters the weak penumbral shadow cast by Earth.įortunately, no matter which type occurs, a lunar eclipse is observable anywhere on Earth from which the Moon appears above the horizon at that time. If the Moon skims part way into the umbra, only the partial phases occur. If it goes all the way in, we see a total lunar eclipse that's preceded and followed by partial phases. Three types of lunar eclipse are possible ( total, partial, and penumbral) depending on how deeply the full Moon plunges into or near the umbra, our planet's dark, central shadow. (The technical name for that, by the way, is syzygy.) These alignments don't occur at every new and full Moon because the lunar orbit is tipped about 5° to Earth's orbital plane - only occasionally do the Sun, Earth, and Moon line up exactly enough for an eclipse to occur. Conversely, a lunar eclipse occurs during full Moon, when our satellite passes through Earth's shadow. Click on the image for a larger view.Ī solar eclipse happens only at new Moon, when the lunar disk passes directly between us and the Sun. But when the Moon is slightly farther from Earth, its disk appears to small to block the entire Sun, and an annular (or ring) eclipse results. ![]() ![]() When the Moon passes directly between the Sun and Earth, its umbra (shadow cone) reaches Earth's surface and thus completely covers the Sun. (The fewest possible is four.) Notably, in any given year only two annular or total solar eclipses can occur - as will be the case in 2013. Up to seven eclipses of the Sun and Moon can take place in one year, though the last time that happened was 1982. ![]() Meanwhile, the dearth of total lunar eclipses continues - and this year's penumbral (barely) partial events are only of academic interest. A select few observers are heading to Australia in May to see an annular solar eclipse, and in November they'll go to Africa to witness a "hybrid" solar eclipse that begins as an annular but transitions to total. Unfortunately, this long-distance trend continues in 2013. For example, Australia was the destination of choice for November 2012's view of totality. None are total lunar eclipses, but major eclipses of the Sun occur in May (an annular visible from Australia and the South Pacific) and November (a "hybrid" visible from central Africa).ĭiehard eclipse-chasers (or umbraphiles) have traveled great distances to see the last few total solar eclipses. ![]()
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