The Geminid meteor shower – always a highlight of the meteor year – will peak in 2018 around the mornings of December 13 and 14. Geminid meteors tend to be few and far between at early evening, but intensify in number as evening deepens into late night. Observing around 2 a.m. is best. This shower favors Earth’s Northern Hemisphere, but it’s visible from the Southern Hemisphere, too. The curious rock comet called 3200 Phaethon is the parent body of this shower. Follow the links below to learn more about the Geminid meteor shower in 2018.
How to watch the Geminid meteors in 2018. You can indeed watch this shower in the evening (late evening is best). But the greatest number of meteors will fall in the wee hours after midnight, centered around 2 a.m. local time (the time on your clock no matter where you are on Earth), when the radiant point is highest in the sky. As a general rule, the higher the constellation Gemini climbs into your sky, the more Geminid meteors you’re likely to see.
These meteors are often bold, white and bright. On a dark night, you can often catch 50 or more meteors per hour.
You need no special equipment – just a dark, open sky and maybe a sleeping bag to keep warm. Plan to sprawl back in a hammock, lawn chair, pile of hay or blanket on the ground. Lie down in comfort, and look upward.
By the way, you don’t need to find a meteor shower’s radiant point to see the shower. The meteors will appear in all parts of the sky. It’s even possible to have your back to the constellation Gemini and see a Geminid meteor fly by. However, if you trace the path of a Geminid meteor backwards, it appears to originate from within the constellation Gemini.
When you’re meteor-watching, it’s fun to bring along a buddy. Then two of you can watch in different directions. When someone sees one, they can call out “meteor!” This technique will let you see more meteors than one person watching alone will see.
Be sure to give yourself at least an hour of observing time. It takes about 20 minutes for your eyes to adapt to the dark.
Be aware that meteors often come in spurts, interspersed with lulls.
Geminid’s parent – 3200 Phaethon – is a “rock comet” Every year, in December, our planet Earth crosses the orbital path of an object called 3200 Phaethon, a mysterious body that is sometimes referred to as a rock comet. The debris shed by 3200 Phaethon crashes into Earth’s upper atmosphere at some 80,000 miles (130,000 km) per hour, to vaporize as colorful Geminid meteors.
In periods of 1.43 years, this small 5-kilometer (3-mile) wide asteroid-type object swings extremely close to the sun (to within one-third of Mercury’s distance), at which juncture intense thermal fracturing causes it to shed yet more rubble into its orbital stream.
In 2017, 3200 Phaethon was exceedingly nearby around nights of the Geminid meteor shower’s peak. This object swept to within 0.069 astronomical units (6.4 million miles, 10.3 million km, 26 lunar-distances) on December 16, 2017 at 23 UTC; translate to your time zone. Click here to know 3200 Phaethon’s present distance from the Earth and sun.
An earthgrazer meteor possible at early evening. You won’t see as many Geminid meteors when the constellation Gemini sits close to the eastern horizon during the evening hours. But the evening hours are the best time to try to catch an earthgrazer meteor.
An earthgrazer is a slow-moving, long-lasting meteor that travels horizontally across the sky.
Earthgrazers are rarely seen but prove to be especially memorable, if you should be lucky enough to catch one.
Why are these meteors called the Geminids? If you trace the paths of the Geminid meteors backward, they all seem to radiate from the constellation Gemini the Twins.
This shower’s radiant point nearly coincides with the bright star Castor in Gemini. That’s a chance alignment, of course, as Castor lies about 52 light-years away while these meteors burn up in the upper atmosphere, some 60 miles (100 km) above Earth’s surface.
Again, you don’t need to find the constellation Gemini to watch the Geminid meteor shower. These medium-speed meteors streak the nighttime in many different directions and in front of numerous age-old constellations.
Bottom line: Meteor showers are part of nature and so inherently unpredictable. But the reliable Geminid shower counts as one of the year’s best, peppering the nighttime sky with 50 or more meteors per hour at its peak.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.