Santa's sleigh isn't even packed yet, but the December sky already has a few celestial gifts at the ready to close out 2017. So warm up your gloves by the fire, pour the hot chocolate and bundle up for a month of spectacular meteor showers, star gazing and one very big moonrise.
Bask in the glow of the only supermoon of 2017 (Dec. 3)
A 2016 November supermoon rising above Lick Observatory in California. (Photo: Wilson Lam/flickr)
While 2016 had no less than six spectacular supermoons, 2017 decided to save the festivities for one big bold hurrah on Dec. 3. That evening, at approximately 3:45 a.m. EST, the full moon will become a supermoon at perigee, or the point in its orbit when it is closest to Earth. As a result, according to National Geographic, it will appear "about 7 percent larger and 16 percent brighter than usual."
While the Old Farmer's Almanac referred to December's big lunar event as the "Cold Full Moon," native people of North America also referred to it as the "Big Spirit Moon," "Blue Moon," and the "Snow Moon." In New Zealand, where summer will soon be underway, this lunar season is described as "birds are now sitting in their nests."
Want to snap the perfect photograph of this year's only supermoon? Check out these tips from Popular Photography.
Gaze upon the mysterious Geminids meteor shower (Dec. 13-14)
A colorful Geminid meteor captured over the volcano Mount Teide in the Canary Islands, Spain. (Photo: StarryEarth/flickr)
One of the most prolific meteor showers of the year, with 120 to 160 shooting stars per hour, the Geminids are also one of the most scientifically perplexing. Whereas most meteor showers come from periodic comets shedding debris as they pass around the sun, the Geminids instead apparently are tied to an asteroid named 3200 Phaethon.
"Of all the debris streams Earth passes through every year, the Geminids' is by far the most massive," NASA astronomer Bill Cooke said in a statement. "When we add up the amount of dust in the Geminid stream, it outweighs other streams by factors of 5 to 500."
The problem is that the asteroid Phaethon (more on that below) is simply not large enough to account for this massive collection of debris. In fact, even though it ejects some dust as it heats during its rendezvous with the sun, the expelled mass accounts for only 0.01 percent of the total Geminids debris stream. The only other explanation scientists can come up with is that Phaethon was once much larger and much more chaotic with the amount of debris it spewed into space.
"We just don't know," Cooke said. "Every new thing we learn about the Geminids seems to deepen the mystery."
To gaze upon this mystery for yourself, look up on the evening of Dec. 13. The shower itself will peak on Dec. 14 at about 1:20 a.m. EST.
A close shave from the asteroid Phaethon (Dec. 16)
The movement of asteroid Phaethon as captured by the Cassegrain telescope of Winer Observatory in Sonoita, Arizona, in December 2010. (Photo: Marcoaliaslama/Wikimedia Commons)
Speaking of Phaethon, the source of the Geminids will make its closest approach to Earth in 40 years on Dec. 16 at a distance of 6.4 million miles (or roughly 27 times the distance between the Earth and moon). The three-mile-wide asteroid, discovered in 1983, is named after Phaëton, son of the sun god Helios, because its orbit takes it closer to the sun than any other named asteroid.
Despite being classified by NASA as a "potentially hazardous asteroid," Phaethon's orbit has been calculated out to pose no threat to Earth for at least the next 400 years. During its closest approach on the 16th, Phaethon will brighten to magnitude 10.7, bright enough to track in a 3-inch telescope. Those without gear can also catch the asteroid's journey through the stars via live streams from observatories in Arizona and Italy.
Should you miss out on viewing the flyby of this ancient comet, prepare to patiently wait for its next closeup. Phaethon won't return this close to Earth until December 2093.
While the (new) moon is away, the stars will play (Dec. 18)
The Milky Way stretching over Lütispitz mountain in Switzerland. (Photo: Lukas Schlagenhauf/flickr)
A new moon is when the moon is located on the same side of the Earth as the sun, and Dec. 18 will offer the perfect conditions to head outside into the darkness and revel in mother nature's nighttime decorations. It's also the perfect time for hobbyist and professional astronomers alike to set up telescopes and check out galaxies, planets, asteroids or other distant objects.
Celebrate the winter solstice (Dec. 21)
A hiker in Iceland observing the winter solstice in December 2014. (Photo: Hafsteinn Robertsson/flickr)
The winter solstice, that brief moment when the sun is exactly over the Tropic of Capricorn, will take place on Dec. 21 at 11:28 a.m. EST.
While the winter solstice features the longest night of the year for those of us freezing in the Northern Hemisphere, it also brings with it the hope of more light in the days and months that follow. Because the sun is at its lowest arc in the sky, the 21st is also a time to get out and see extremely long shadows. "Your noontime shadow on the solstice is the longest it will be all year," MNN's Melissa Breyer points out. "Relish those long legs while you can."
Catch the Ursids meteor shower (Dec. 23-24)
A shooting star captured over British Columbia, Canada. (Photo: Alain De Loor/flickr)
While the Ursids have a tough act to follow after the spectacular Geminids, this annual meteor shower is still capable of throwing down up to 10 shooting stars per hour. Originating from debris shed by Comet 8P/Tuttle, the Ursids appear to originate from the constellation Ursa Minor. Bundle up, get comfortable, and gaze up on the evening of the 23rd or 24th to catch the peak of this holiday shower. The bonus of a thin crescent moon with very little light interference should make spotting even dimmest of meteors an easy affair.