What will potentially be the best meteor display of the year is upon us, culminating late Wednesday night/early Thursday morning, December 13-14: the Geminids meteor shower.
If you’re disappointed by the lackluster showing of last month’s Leonid meteor shower, don’t worry. The Geminids meteors are usually the most satisfying of all annual showers, even surpassing August’s famous Perseids. Research into past phenomena shows that this shower has a reputation for being rich in slow, bright, graceful meteors and fireballs as well as faint meteors, with relatively fewer objects of medium brightness. Geminids typically encounter Earth at a speed of 35 km per second; about half the speed of a Leonid meteor. Many appear yellowish in hue. Some have even been seen to form jagged or divided paths.
The Geminids get their name from the constellation Gemini, the Twins. On the night of this shower’s maximum, the meteors will appear to come from a spot in the sky near the bright star Castor in Gemini.
The Earth moves quickly through this meteor stream, producing a slightly broad, skewed activity profile. Rates rise steadily for two or three days before the maximum, reach roughly above a quarter of peak strength, and then fall more sharply. However, late Geminids are particularly bright. Renegade precursors can be seen a week or more before maximum, but three nights after peak activity the Geminids are virtually gone for another year.
Related: Meteor showers 2023: when is the next one?
Excellent conditions in 2023
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The Geminids perform excellently in any year, but 2023 can be categorized as a ‘fantastic year’. Last year’s exhibition in contrast, was seriously affected by bright moonlight when a bright moon appeared over the horizon in the late evening hours and with its bright light blotted out many of the fainter Geminid stripes.
But this year the moon will be in a new phase on December 12. On peak night, the moon will be a thin crescent, low in the west-southwest at sunset and setting around 5pm on Wednesday evening. That means the sky will be dark and moonless for the rest of the night, making for perfect viewing conditions for the shower.
According to Margearet Campbell-Brown and Peter Brown in the Royal Astronomical Society of Canada’s 2023 Observer’s Handbook, the Geminids are predicted to reach peak activity at 2:00 PM EDT (1900 GMT). That means that those places from Eastern Europe and Northeast Africa, eastward to Central Russian and Chinese longitudes, are in the best position to catch the top of the shower, while speeds could conceivably exceed 120 per hour! But maximum speeds persist at only marginally reduced levels for around the greatest 6 to 10 hours, so other places (like North America) should enjoy nice Geminid activity as well.
Under normal conditions on the night of maximum activity, with ideal dark sky conditions, an average of at least 60 or more Geminid meteors can be expected to burst across the sky every hour (light pollution significantly reduces the numbers).
Best view after 10pm
Generally, depending on your location, Gemini begins to appear over the east-northeast horizon around the time evening twilight ends. So you may see some early Geminids once the sky darkens. There’s also a fair chance that you might see some “earth-grazing” meteors. Earthgrazers are long, bright shooting stars that shoot above us from a point near or even just below the horizon. Such meteors are so distinctive because they follow long paths that run almost parallel to our atmosphere.
The Geminids begin to appear noticeably more numerous in the hours after 10:00 PM local time, as the radiation shower is already quite high in the eastern sky by then. The best views, however, come around 2 a.m., when their beam point will pass almost overhead. The higher the radiation of a rain shower, the more meteors it produces everywhere in the sky.
Bundle up!
But keep this in mind: At this time of year, meteor watching can be a long, cold affair. You wait and you wait for meteors to appear. If they don’t appear right away, and you’re cold and uncomfortable, you won’t be looking for meteors for long!
A night in a sleeping bag under the stars is an attractive proposition in summer, and as a result many holiday campers “discover” the Auguste Perseids on their own. But it’s a very different story for the Geminids, who have to lie on the ground or on a long lawn chair for several hours after midnight in December, looking up at a clear sky that has brought radiative cooling and plummeting temperatures since sunset.
The late Henry Neely (1879-1963), who served for many years as a popular lecturer at the Hayden Planetarium in New York, once said this about looking out for the Geminids: “Take the advice of a man whose teeth have at many times have chattering teeth. winter night: dress much warmer than you think is necessary.”
Hot chocolate or coffee can take the edge off the cold, but also provide a mild stimulus. It’s even better if you can observe with friends. That way you can keep each other awake and cover more air. Give your eyes time to adjust to the dark before you start.
Progenitor is an asteroid
Geminids differ from the other meteor showers in that they appear to be produced not by a comet, but by 3200 Phaëthon, an active, Earth-crossing Apollo asteroid with an orbit that brings it closer to the Sun than any other asteroid. For this reason it is named after the Greek myth of Phaëthon, son of the sun god Helios.
On the other hand, the Geminids may be cometary remnants after all, as some astronomers consider Phaethon to actually be the dead nucleus of a burned-out comet that has somehow ended up in an unusually tight orbit.
If you want to try photographing the Geminids or another meteor shower, be sure to check out our guide to photographing meteors and meteor showers. And if you need imaging equipment, consider our best cameras for astrophotography and the best lenses for astrophotography.
Editor’s Note: If you take a great photo of the Geminids meteor shower that you would like to share with Space.com and our news partners for a story or photo gallery, please send images and comments to spacephotos@space.com.
Joe Rao is an instructor and guest lecturer in New York Hayden Planetarium. He prescribes on astronomy Natural history magazinethe Farmer’s almanac and other publications.