Now here’s something you don’t see every day, every year or even every century. North America gets to view a total lunar eclipse as Fall passes the seasonal baton to Winter.
It is the day planet Earth groans and grunts because she can’t turn her South Pole toward the Sun any more than she already has. She resigns and begins turning her North Pole toward the Sun.
The winter solstice comes but once a year, December 21, every year. That’s just how it is. When inhabitants of Earth figured out we’d been thrown the cosmic curve ball of a leap year, calendars began to make more sense. Simply put, the winter solstice is the shortest day of the year. That’s the confusing explanation, because every day is 24-hours long. Daylight hours, however, vary depending on how far north or south one lives from the Equator. Summer solstice is just the opposite, June 21, most daylight of any day, and marks the beginning of summer.
Lunar eclipses are another matter, occurring when the Earth casts its shadow upon the moon as it passes between it and the sun. Total eclipses totally cover the moon with the earth’s shadow, blacking it out, darkening the sky until for a few moments until it reappears as a sliver facing the one that disappeared. Tonight’s moments of complete blackness, technically referred to as ‘totality,’ will be more than a few at around 72 minutes, during which “an amber light will play across the snows of North America, throwing landscapes into an unusual state of ruddy shadow.” Every bit as predictable as solstices if you know the math, lunar eclipses occur irregularly. True, not all lunar eclipses occur at night. But the ones that do when they are dazzling.
This cosmic triple play of a full moon at total eclipse during the winter solstice has not occurred in more than 600 years. “Since Year 1, I can only find one previous instance of an eclipse matching the same calendar date as the solstice, and that is 1638 DEC 21,” says Geoff Chester of the US Naval Observatory, who inspected a list of eclipses going back 2000 years. The next one happens near the end of this century in 2094.