Winter Solstice: 2018's Longest Night Ushers in Full Moon and Ursid Meteors
Why the longest night of the year won't be all that dark.
The astronomical year culminates in Friday’s winter solstice, the longest night of the year for folks in the Northern Hemisphere. But that doesn’t mean it’ll be especially dark tonight: This year, a relatively rare kind of solstice coincides with two dazzling displays of celestial light to pierce the December darkness.
As long as clouds don’t creep in during the night, your winter solstice should be illuminated by a full moon nicknamed, somewhat creatively, the Cold Moon or the Long Night’s Moon. The last time a winter solstice coincided with a full moon was in 2010, and it won’t happen again until 2094.
If its lunar glow isn’t too bright, you might just catch a smattering of Ursid meteors scatter across the night sky — this year’s shower is expected to produce double the usual five to ten shooting stars per hour. Because of the Ursids’ unfortunate juxtaposition with the scene-stealing moon, NASA meteor expert Bill Cooke has referred to this year’s shower as the “Cursed Ursids.”
The Ursid meteors will appear to shower down from Ursa Minor, the little bear.
What is the Winter Solstice?
The word “solstice” comes from a mash-up of two Latin terms: sol, for Sun, and stitium, for stoppage. To ancient sky-watchers, this night marked the moment the sun appeared to stop in the sky at midday, and for one night, it appears as though the sun orbits around the Earth.
This all comes down to the fact that Earth is tilted with respect to its orbit, much as a traditional globe shows. Over the course of a year, the North Pole tilts toward the sun, bathing more of the globe in light, then eventually tilts away from it, casting the long shadows of the winter solstice.
The time-lapse video above shows how the Sun’s rays hit Earth at different angles over the course of the year, and the photo below shows where the Sun’s rays hit during the various solstices and equinoxes.
The tilt of the Earth causes certain parts of the Earth to be bathed in darkness over the year. The top left shows the Sun's rays during the winter solstice, when the Northern Hemisphere gets the least amount of light.
Why the Sun Stands Still
If you go outside at midday local time on Friday, the Sun will appear to be at the lowest point it’s been in the sky over the whole year — that is, it will “stand still.” Tomorrow, it will appear a little bit higher, starting its slow climb back up to the longest day of the year, in June.
But if you’re going to venture outside at all, save your warmth for the night sky. The Cold Moon will be waiting, along with the elusive Ursids showering down from Ursa Minor, the sky’s little bear. Bright solstice, everyone!
Watch everyone’s favorite teen witch ring in a spooky winter solstice in the Chilling Adventures of Sabrina trailer below.
