Meteor Showers, a Supermoon, and the Solstice: A Guide to the December Night Sky

Thomas Coex/AFP/Getty Images
Thomas Coex/AFP/Getty Images

This has been a fantastic year for sky watching. Eclipses in particular had their day in the Sun, with celestial objects blotting each other out as if in competition. There was a penumbral lunar eclipse and an annular solar eclipse in February, and then in August, a partial lunar eclipse was followed up by a mind-blowing total solar eclipse. If you missed any or all of those events, don't lose heart: they will happen again and again and again, in your lifetime and beyond. Celestial mechanics guarantee it. The year isn't over yet, though, and December has a few wonderful events up its sleeve. Here are four things you should be on the lookout for in the skies above.

DECEMBER 3: THE ONLY SUPERMOON OF 2017

I know, supermoons are so 2016. There were six that year, if you don't recall. (I do, because I had to think of new things to write about every single one of them.) This year has been a bit less active in terms of super lunar events, with a total of zero must-see giant moons for your viewing pleasure. That changes on December 3 with the first and only supermoon of the year, and it has a great name at that: the Full Cold Supermoon. The "cold" part of the name, according to the Old Farmers Almanac, derives from Native American tradition. (They weren't being creative here; it's just really cold in December.) The "super" part is because the Moon will be at perigee—that is, the closest to Earth it's going to get in its orbit. The moon's orbit is not a perfect circle, meaning it sometimes appears larger in the sky than others.

Expect a moon that's about 14 percent larger than when it is at apogee (farthest from Earth), though, unless you are an obsessive moonwatcher, the larger size will be nearly imperceptible. My advice is to point at the moon when your friends are around and say something like, “Hey, check that out. I think that's a supermoon! You might not notice a difference, but I sure do. Compared to the moon at apogee, it's huge! Why, it's got to be 14 percent larger, at least. Wow!” Then change the subject quickly, because nobody likes a know-it-all.

DECEMBER 13–14: MORE THAN 100 METEORS PER HOUR

The Geminid meteor shower is considered the best meteor shower of the year, and it peaks after midnight between December 13 and 14. If you are in an area of low (or no) light pollution, and if you give your eyes an hour to adjust to total darkness, and if the weather is good (a lot of "ifs," but worth it if you can arrange things), you can expect to see more than 100 meteors per hour. Geminid meteors are a result of the Earth colliding into the debris field of the asteroid Phaethon, an unusual "rock comet" that leaves behind dust- and sand-sized particles as it circles the Sun. A speck of dust might not seem like much, but when the atmosphere of a 13,170,000,000,000,000,000,000,000-pound planet plows into it at tens of thousands of miles per hour, it is vaporized in a beautiful streak of light.

As if that isn't cool enough, on December 16, Phaethon itself will make its closest approach to Earth in 43 years! Yes, the Minor Planet Center officially considers Phaethon to be a "potentially hazardous object," but before you dust off your Y2K prepper supplies, know that the asteroid will be 27 times farther away than the Moon generally is from the Earth. Sadly, it is unlikely to affect the meteor shower in any measurable way.

DECEMBER 21: THE WINTER SOLSTICE

December 21 will play host to the longest night of the year. Why? Because the Earth's axis is tilted by about 23.5 degrees, and as we orbit the Sun, different latitudes are in direct sunlight. Presently, the southern hemisphere is “closer” to the Sun than the northern. On the 21st, the Tropic of Capricorn (latitude -23.5 degrees) will be in the overhead sun and will receive 13 hours, 27 minutes of daylight. The higher in latitude you go from the Tropic of Capricorn, the less daylight that part of the Earth will receive. The equator will get 12 hours of sunlight. The North Pole will get zero seconds of daylight. The Tropic of Cancer will get about 10.5 hours.

We call this the Winter Solstice, and it's when you'll find some of the best parties of the year. That much night, after all, and anything can happen. Starting on the 22nd, the days will begin to get longer in the northern hemisphere, with spring soon to follow.

DECEMBER 22: THE URSID METEOR SHOWER

Just before sunrise on the morning of December 22, as you're stumbling home from that killer Winter Solstice party, look up. Well, first find a spot with low light pollution and give your eyes time to adjust, and then look up. You will be treated to the annual Ursid meteor shower, here to ring out 2017—and not a minute too soon.

The Ursids are no Geminids; at best you'll only catch 10 meteors an hour, but because the Moon will be but a sliver, the natural skies should be nice and dark. Weather not cooperating? Don't worry. You should be able to catch an Ursid or two through December 25. (Note that on the night of the 24th, what you suspect is an Ursid might be a sleigh carrying cargo and an elderly, bearded man. A distinct red hue will help you distinguish the two. One is a shooting star. The other is Rudolph's nose.)

Tonight, the Lyrid Meteor Shower Peaks on Earth Day

iStock/dmoralesf
iStock/dmoralesf

Tonight, look up and you might see shooting stars streaking across the sky. On the night of Monday, April 22—Earth Day—and the morning of Tuesday, April 23, the Lyrid meteor shower will peak over the Northern Hemisphere. Make some time for the celestial show and you'll probably see meteors zooming across the heavens every few minutes. Here is everything you need to know about this meteor shower.

What is the Lyrid meteor shower?

Every 415.5 years, the comet Thatcher circles the Sun in a highly eccentric orbit shaped almost like a cat's eye. At its farthest from the Sun, it's billions of miles from Pluto; at its nearest, it swings between the Earth and Mars. (The last time it was near the Earth was in 1861, and it won't be that close again until 2280.) That's quite a journey, and more pressingly, quite a variation in temperature. The closer it gets to the Sun, the more debris it sheds. That debris is what you're seeing when you see a meteor shower: dust-sized particles slamming into the Earth's atmosphere at tens of thousands of miles per hour. In a competition between the two, the Earth is going to win, and "shooting stars" are the result of energy released as the particles are vaporized.

The comet was spotted on April 4, 1861 by A.E. Thatcher, an amateur skywatcher in New York City, earning him kudos from the noted astronomer Sir John Herschel. Clues to the comet's discovery are in its astronomical designation, C/1861 G1. The "C" means it's a long-period comet with an orbit of more than 200 years; "G" stands for the first half of April, and the "1" indicates it was the first comet discovered in that timeframe.

Sightings of the Lyrid meteor shower—named after Lyra, the constellation it appears to originate from—are much older; the first record dates to 7th-century BCE China.

How to See the Lyrid Meteor Shower

Monday night marks a waning gibbous Moon (just after the full Moon), which will reflect a significant amount of light. You're going to need to get away from local light pollution and find truly dark skies, and to completely avoid smartphones, flashlights, car headlights, or dome lights. The goal is to let your eyes adjust totally to the darkness: Find your viewing area, lay out your blanket, lay down, look up, and wait. In an hour, you'll be able to see the night sky with great—and if you've never done this before, surprising—clarity. Don't touch the smartphone or you'll undo all your hard ocular work.

Where is the nearest dark sky to where you live? You can find out on the Dark Site Finder map. And because the shower peaks on a Monday night—when you can expect to see 20 meteors per hour—your local astronomy club is very likely going to have an event to celebrate the Lyrid meteor shower. Looking for a local club? Sky & Telescope has you covered.

Other Visible Bodies During the Lyrid meteor shower

You don't need a telescope to see a meteor shower, but if you bring one, aim it south to find Jupiter. It's the bright, unblinking spot in the sky. With a telescope, you should be able to make out its stripes. Those five stars surrounding it are the constellation Libra. You'll notice also four tiny points of light nearby. Those are the Galilean moons: Io, Europa, Ganymede, and Callisto. When Galileo discovered those moons in 1610, he was able to prove the Copernican model of heliocentricity: that the Earth goes around the Sun.

What to Do if There's Bad Weather During the Lyrid Meteor Shower

First: Don't panic. The shower peaks on the early morning of April 23. But it doesn't end that day. You can try again on April 24 and 25, though the numbers of meteors will likely diminish. The Lyrid meteor shower will be back next year, and the year after, and so on. But if you are eager for another show, on May 5, the Eta Aquarids will be at their strongest. The night sky always delivers.

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the Moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the Moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the Moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the Moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception—in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full Moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

This story was updated in 2019.

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