Geminids are the underappreciated annual event of the astronomical calendar since they occur in mid-December when it's often too cold and cloudy in the Northern Hemisphere to really appreciate them.
And it's a shame since the Geminids are almost always a better show than their summer counterparts, the much more popular Perseids. If you have a clear, dark sky and are willing to brave the cold, it's worth the effort to deal with those chilly temperatures. Plus, who doesn't love drinking hot chocolate while watching meteors streak above?
When and where to look
The Geminids peak around the mornings of Dec. 13 and Dec. 14, with the latter probably your best bet, around 2 a.m. local time. It's not a great idea to just pop out that early in the morning, however. You'll need to be outside at least 20 minutes to give your eyes some time to adjust to the darkness. Then and only then will you be able to see the Geminids. Plan to be outside for an hour or so to get the full experience.
The meteors' radiant point is almost alongside the bright star Castor, found in the — you guessed it — Gemini constellation. However, don't sweat it if you're unable to locate Gemini. You can have your back turned to the constellation and still the meteors fly overhead.
What should I expect?
A slower meteor experience.
Leonids streak by, but Geminids are, in the words of instructor and guest lecturer at New York's Hayden Planetarium Joe Ra Joe Rao, "celestial field mice," slowly scurrying across the sky. You should see a number of bright yellow-white streaks or some very dim ones. There are not many meteors in between that range, according to Rao.
As for the number of meteors, you can expect an average of 60 to 120 an hour, but light pollution and cloud cover will influence how many you actually see. The moon may also pose an issue as it reaches its first-quarter phase on Dec. 15. Some bright moonlight may then drown out the dimmer of the meteors. That said, it's worth considering how the 2012 Geminid shower went.
What should I bring with me?
You won't require any special viewing devices to see the Geminids, just your eyeballs adjusted to the darkness of the night.
You will, however, require ways to stay warm since it's mid-December and may be quite cold in the Northern Hemisphere. Dress smartly in warming layers, have some warm non-alcoholic drinks near by and, of course, bring some friends! If you all pick a section of the sky to watch, then you can get more of the experience. Any time someone spots a meteor, they should simply say, "Meteor!" and people can turn their heads and spot it.
If you need a sky-gazing break, bring a book with a red light to read by so you won't need to give your eyes time to readjust to the dark.
Where do the Geminids come from?
Geminids originate from an object called 3200 Phaethon. Phaethon is a quirky celestial creature since it's an asteroid but its orbit is far more similar to a comet, meaning a more elongated than round orbit. That, coupled with its composition being somewhat comet-like, garnered Phaethon the moniker "rock comet." When it was discovered the early 1980s, it was quickly identified as the until-then unknown source of the Geminids.
In 2017, Phaeton caused a bit of stir since it was easily visible with some small telescopes as it swept a mere 6.4 million miles (10.3 million kilometers) away from Earth. In addition to being able to see Phaethon, its proximity to Earth resulted in a better-than-usual Geminid shower that year. In 2018, Phaethon will be much further away, resulting in what will likely be a normal meteor shower. If you're hoping to catch a glimpse of Phaeton, it should skate by at a distance of 1.8 million miles on Dec. 14, 2093, so set a reminder on your calendar app.