The latest episode of cosmic action in the night sky is the Leonids meteor shower. The monthlong event will peak overnight into the early hours of Wednesday.
If you’re thinking about staying up late for the show, keep in mind that a nearly full moon is likely to outshine some of the tantalizing streaks that observers can easily spot on darker nights.
What are meteor showers?
As the Earth circles the sun, it passes through trails of debris spewed from comets and asteroids. Stray remnants of these trails become meteors when they get swept into the planet’s atmosphere, where they burn up during their brief descent.
The result: meteor showers, also nicknamed “shooting stars,” which can last from dusk to dawn and dazzle the night sky with quick streaks of light.
The latest event is the Leonids, whose meteors come from the material left behind in the dusty trail of the comet Tempel-Tuttle. It takes the comet 33 years or so to make a full orbit around the sun, venturing beyond the orbit of Jupiter and swinging back toward the inner solar system.
Each November, as Earth swings into old trails of the comet, meteors splash into the atmosphere, drawing uniquely colorful streaks of light. Tempel-Tuttle’s next close visit will happen in May 2031, leaving a fresh trail of fragments that will pelt Earth’s atmosphere for centuries to come.
But predicting the intensity of the meteor showers produced by the comet from year to year isn’t easy.
Some Leonids showers become meteor storms, when cometary fragments careen through Earth’s atmosphere at much higher rates from 1,000 to hundreds of thousands per hour from the comet’s past close visits. The celestial material from those heightened periods of activity hail from flybys of past decades. During storms witnessed in 2001 and 2002, for instance, the material came mostly from the comet’s pass in 1766. Mikhail Maslov, a Russian astronomer, predicts the next major burst will occur in 2034, producing up to 500 meteors per hour.
In a more typical year like 2021, the showers yield about 15 visible meteors each hour.
How to watch
Midnight on Tuesday through dawn on Wednesday morning are the prime viewing hours to catch the Leonids in action. NASA recommends setting up a sleeping bag and lying flat on your back in an open area outside with few obstructions to the night sky, somewhere far from the light pollution of cities and towns.
Keep a wide eye on the sky — using binoculars or telescopes would narrow your field of view.
Meteor showers are named after the constellations in the night sky from which they appear to shoot, and the Leonids tend to streak from the Leo constellation, a formation of stars situated in the Northern celestial hemisphere. Keep an eye near the Leo constellation, but don’t focus too hard. The bright streaks of light can dart across any part of the night sky as celestial debris careens into the atmosphere.