The most active shooting stars of the year are the Geminids, the sky’s “Old Faithful.” Their trustworthy, one‑a‑minute frequency has created reliable December sparklers for the past century. In 2021, the Moon is out for part of the night, so check out my 8 tips for how to best view the shooting stars this year.
In 2021, the Geminids will peak on the night of Monday, December 13, into the morning of Tuesday, December 14. However, the best time to view depends on the Moon phase!
If you wish, go straight to the Almanac’s Geminid Meteor Shower Guide. Or, read on for my 8 astronomy tips to get the most of the Geminids this year.
8 Tips for Watching the Geminids
The great thing about the Geminids is that they are out all night long. They are more frequent around 2 A.M., but you can watch them starting in the early evening until dawn the next day.
In 2021, the waxing gibbous Moon is about 75% to 80% full (see your Moon phase calendar). Given this challenge, you have a couple options: Instead of staying up until 2 A.M., set your alarm and get up in the dark predawn hours on Tuesday the 14th. These are the hours after the Moon has set (around 3 AM this year) and before the Sun rises (around 5:30 AM). See your local moonset and local sunrise to check times near you. The other option is to look towards the part of the sky that is darkest, away from the Moon, at any time of night.
You can see the Geminids from ANYWHERE in the Northern Hemisphere. Yes, even in your town. It does not matter where you live.
In an especially dark sky free of moonlight, you may see between 75 and 100 meteors per hour! In a normal year with some moonlight, we’d expect to see 50 to 60 shooting stars per hour—if you’re viewing from a dark place without light pollution.
Of course, as with all meteor watching and stargazing, do try to drive away from city lights, to a place with an open expanse of sky, not just breaks between trees. Bring a folding chair to be comfortable or perhaps a sleeping bag. Dress warmly. You’ve got to be a little nuts to do this in the middle of December. (But it’s worth it!)
It takes our eyes about 20 minutes to truly adapt to dark skies. The Geminid meteor showers tend to come fast and quick with very bright white lights.
The meteors will appear anywhere in the full expanse of the night sky. Don’t bother hunting for the Geminids’ radiant point (the constellation Gemini), as the meteors will be easily seen throughout the sky.
Leave the telescope at home. For a show like the Geminids, there’s no need for fancy equipment. Your eyes will do just fine.
What’s better than stargazing alone on a dark night? Bringing along a friend so that you can double your meteor-spotting capabilities! Heck, make it a competition. The loser has to buy the other breakfast.
Be patient and keep your eyes glued upward!
Geminid Facts and Oddities
Geminids are much slower than either the famous summer Perseids or the hit‑or‑miss Leonids because they don’t strike us head‑on. They come at Earth sideways. At 20 miles per second, they lope along at half the speed of the other major showers, and it shows. It’s very appealing. Instead of sharp, brief zaps across the sky, we get leisurely streakers.
These meteors are also the most mysterious in the known universe. All other showers are debris from comets, skimpy stuff less dense than ice. Strangely, Geminid meteors are twice as dense, yet nonetheless too lightweight to be bonafide, metal-stone asteroid material. So what could they be?
There are other oddities too. All other major meteor showers have been observed for centuries or millennia. But the Geminids were unseen as recently as the mid‑1800s, when it started as a modest shower that delivered only 20 meteors per hour. Over time, it’s grown increasingly rich; now it delivers one to two a minute.
Despite decades of searching, the source of these strange fireworks was unknown until 1983, when NASA’s infrared‑detecting satellite IRAS found a small body moving in exactly the same path as the meteoroid swarm. Named Phaethon, it has a speedy orbit that carries it far within the orbit of Mercury and then out past Mars into the asteroid belt. Since Phaethon does not develop a comet-like tail nor shed material when approaching the sun, it was assumed to be an asteroid, a rocky body.
Fine. Except asteroids don’t disintegrate to produce meteor showers: Curioser and curioser. Maybe Phaethon is a true rocky asteroid that suffered enough collisions to fill its lopsided orbit with debris. Or else, maybe Phaethon is an odd has‑been comet, one that completely lost its icy outer covering and is presently just a comet‑core that has perhaps acquired a coating of interplanetary dust grains. Either way, the mystery material puts on quite a show.