Geminids are the most underappreciated annual event of the astronomical calendar. 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 on Dec. 14, with the best display around 2 a.m. local time, though they will be visible from now through Dec. 17, roughly from dinner time until around 6 a.m.
If you're waiting for the peak moment, don't just pop out that early in the morning, however. You'll need to be outside at least 20 minutes beforehand to give your eyes 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.
To get a more detailed description of where to look in the sky, check out a handy tool from In-the-Sky.org, which gives you a good approximation after you input your location on the right.
The meteors' radiant point is almost alongside the bright star Castor, found in the Gemini constellation. (Not surprisingly, that's how the shower got its name.) However, don't sweat it if you're unable to locate Gemini. You can have your back turned to the constellation and still see the meteors fly overhead.
What should I expect?
A slower meteor experience, just like you see in the video above from December 2017.
Leonids streak by, but Geminids are "celestial field mice," slowly scurrying across the sky, in the words of Joe Rao, instructor and guest lecturer at New York's Hayden Planetarium. 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 will certainly pose an issue this year, as it's an almost-full waning gibbous moon. That bright moonlight may drown out the dimmer of the meteors, but it won't be a bust by any means. (To get an idea of the possibilities when the moon isn't full, read 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, make sure you stay warm since it's mid-December and may be quite cold in the Northern Hemisphere. Dress smartly in warming layers, have some warm drinks within reach 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 and share what they see.
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 because it was easily visible through even 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.
Editor's note: This story has been updated with new information since it was published in December 2018.