The Geminid meteor shower will put on a stunning celestial show when it peaks later this week, producing up to 120 meteors per hour under ideal conditions. This dazzling show started November 19 and will continue through December 24, but it is expected to peak on December 13 and 14.
Astronomers say the Geminids are worth staying up late for, as they’re the year’s “most consistently prolific shower,” writes the Washington Post’s Geoff Chester.
At the shower’s peak, stargazers should have an especially good view of the shooting stars, because the moon will be in its waxing crescent phase. With very little moonlight, the bright, yellowish meteors will stand out against a dark backdrop under clear skies.
Here’s what to know if you’re planning to watch the Geminids.
Where do the meteors come from?
The Geminids are unique. Most meteor showers occur when the Earth passes through the debris trail of a comet, a frozen snowball of dust, rock and gas orbiting the sun. But instead, the Geminids result from the Earth passing through material that has broken off from an oddball asteroid named 3200 Phaethon.
This rocky piece of space rubble behaves more like a comet than an asteroid—for example, it gets brighter and produces a “tail” of debris when it approaches the sun. Astronomers have called 3200 Phaethon a “rock comet” to acknowledge this abnormality.
The asteroid was first discovered in 1983, and scientists later realized its orbit aligned with the annual mid-December spectacle. When the Earth crosses 3200 Phaethon’s orbit each year, the asteroid’s debris particles collide with our planet’s atmosphere, where they burn up and produce bright streaks of light. But because 3200 Phaethon’s tail is made primarily of sodium gas, not dust, scientists wondered where the meteor-causing material came from.
Earlier this year, data gathered by NASA’s Parker Solar Probe helped astronomers come up with a possible answer to this question. They suspect some disruptive, violent event, such as a crash with another space rock, occurred thousands of years ago and caused the asteroid to spew out debris.
Japan hopes to learn more about 3200 Phaethon with its planned DESTINY+ mission, which has been delayed until 2025. The spacecraft will fly by the asteroid and study its cosmic dust; cameras will also image its surface.
Tips for viewing the Geminid shower
This year, the night of December 13 will likely be the best time for United States-based viewers to see the meteors, writes Sky & Telescope’s Bob King. But watching on the night of December 14 could also be a dazzling experience.
The most impressive phase of the shower will begin around 10 p.m. on the peak night, no matter your time zone. But at 2 a.m. local time, the constellation Gemini will be highest in the sky, giving you the best view of the meteors. This is because the Geminids appear to originate from Castor, a bright star within the constellation. But you don’t need to look directly at this spot, called the radiant, to see the meteors. Instead, keep your gaze roving over the entire night sky.
If you can’t stay up quite that late, consider going outdoors around twilight, per Sky & Telescope.
“While the radiant will be only a few degrees above the horizon at that time, viewing geometry favors the appearance of earthgrazers,” per the publication. “These are slow-burn meteors that skim the upper part of the atmosphere and travel large distances before fading out.”
Whenever you start your stargazing sojourn, be sure to give your eyes enough time to adjust to the dark, a process that typically takes around 20 to 30 minutes. And, for the duration of your meteor viewing experience, don’t look at your phone screen or other bright lights, as they will reduce your night vision. Instead, if you need to see in the dark, use a red headlamp or flashlight.
If you can, venture out to a certified dark sky area—or, at the very least, go somewhere that’s far from light pollution, like a state park, a national park or a national forest. EarthSky’s Deborah Byrd and Kelly Kizer Whitt also recommend bringing along a friend.
“The two of you can watch in different directions,” they write. “When someone sees one, call out, ‘Meteor!’ This technique will let you see more meteors than one person watching alone will see.”