How to Watch the Dazzling Eta Aquarid Meteor Shower, Bringing an Unusual ‘Outburst’ to Skies This Weekend
This year’s spectacle will be more impressive than usual, as the Earth passes through a concentrated clump of 3,000-year-old comet debris
The famous Halley’s comet isn’t due back from its 76-year voyage around the sun until 2061. But you don’t have to wait nearly that long to interact with it. Right now, bits of rock and ice from Halley’s comet are careening through the atmosphere at top speed, visible from Earth as shooting stars during the Eta Aquarid meteor shower.
The Eta Aquarids last from mid-April to late May, with their peak slated for this week. And this year, the Eta Aquarids are expected to put on an even more dazzling show than usual.
Thanks to an uncommon phenomenon called an “outburst,” this weekend will feature more meteors than average, according to NASA. While the peak was originally expected to be the evening of May 4 and into the early morning hours of May 5, the space agency experts predict the outburst activity will occur between May 2 and 6. Roughly 60 meteors per hour—or one per minute—will be visible for sky gazers in the Southern Hemisphere.
The shower isn’t quite as strong in the Northern Hemisphere, but observers in the southern United States should be able to see one meteor every three to four minutes, William J. Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center, tells Smithsonian magazine in an email.
Another good reason to look up? The moon will be in its waning crescent phase during the Eta Aquarids’ peak. With just a thin sliver of the moon illuminated, the sky will be mostly dark.
If you’re curious about the Eta Aquarids, here’s what to know about this meteor shower with a famous parent comet—and how best to watch the spectacle.
Where do the meteors come from?
As with many other meteor showers, the Eta Aquarids occur when Earth passes through a cloud of debris left by a comet. In this case, it’s one of the best-known comets out there: Halley’s comet, otherwise known as 1P/Halley.
English astronomer Edmond Halley officially discovered the comet in 1705. But sky watchers had been seeing it for millennia—they just didn’t know exactly what it was. The first recorded appearance of the comet dates to 240 B.C.E. in China, though possible observations may have occurred even earlier, in 467 B.C.E., according to NASA. Halley’s comet even makes an appearance in the Bayeux Tapestry, a linen cloth that was embroidered with wool thread to tell the story of the Battle of Hastings in 1066.
Prior to 1705, astronomers thought individual comets only zoomed through the solar system once. But Halley realized—by calculating the orbits of several comets—that they often return again and again. He predicted that Halley’s comet would next be visible from Earth in 1758—and though he didn’t live to see it, the astronomer was right.
It takes 1P/Halley an average of 76 years to complete its orbit around the sun. But every time the comet re-enters the inner solar system, it sheds pieces of ice and rock. Earth crosses paths with Halley’s debris field twice a year: once in May (which creates the Eta Aquarids) and again in October (which produces the Orionid shower).
Each time the planet passes through this field, some of the debris enters Earth’s atmosphere. Sometimes, these space rocks fall to the ground as meteorites. But most burn up in the atmosphere, igniting in a streak of light visible from Earth’s surface. These are the meteors, or “shooting stars.”
Halley’s comet measures 5 miles by 9.3 miles. The last time it entered the inner solar system was in 1986—and it won’t return again until 2061. It’s what’s known as a short-period comet, an umbrella term that applies to comets that take less than 200 years to orbit the sun. But until its return, humans get to appreciate the spectacular showers created by its wake.
What is an “outburst” of meteors?
It's time to #WatchTheSkies!
— NASA Marshall (@NASA_Marshall) April 30, 2024
The eta Aquariid meteor shower should put on a spectacular sky show from May 2-6, with meteor rates up to one per minute.
The next time the eta Aquariids will outburst is about 20 years from now. Don't miss it! >> https://t.co/yxx2u8paUD pic.twitter.com/PvzldyAWao
This year, the Eta Aquarids will produce an “outburst,” or a more intense period of meteor activity. Outbursts occur because the gravity of other planets—more specifically, Jupiter—can push a comet’s debris trail toward or away from Earth. In this case, our planet is encountering a concentrated stream of material shed by Halley’s comet during its trip through the inner solar system in 985 B.C.E., which Jupiter has pulled toward Earth’s orbit. This means the fiery streaks crossing skies this weekend will come from material that’s 3,000 years old.
Last year, a clump of Halley’s comet debris from 390 B.C.E. caused an uptick in activity during the Eta Aquarids. But this is unusual, Cooke says.
“Most years, there are no significant debris trails near Earth, just a diffuse ‘background’ of older Halley debris,” he says.
Astronomers predict the next Eta Aquarids outbursts will occur in 2045 and 2046—more than 20 years from now.
Tips for viewing the Eta Aquarids
From Earth, the Eta Aquarids appear to originate from the constellation Aquarius, a point in the sky known as their “radiant.” More specifically, these shooting stars appear to be coming from a bright star named Eta Aquarii.
The best place to be during the Eta Aquarids is in the Southern Hemisphere—where Aquarius appears higher in the sky—but you can still see the meteors from the Northern Hemisphere. Here, the Eta Aquarids often appear at the horizon, as if they’re just barely skimming Earth’s surface. These meteors, nicknamed “Earthgrazers,” can be remarkably bright and extra long, according to NASA.
The best time to watch the Eta Aquarids is during the hours before dawn, because that’s when Aquarius will be at its highest, according to EarthSky.
The Eta Aquarids are especially speedy: They enter the atmosphere while traveling roughly 148,000 miles per hour, or approximately 41 miles per second. This speed is good for sky watchers, because it means the meteors sometimes leave bright “trains” in their wakes that can last for up to a few minutes.
No matter which hemisphere you’re in, you might be tempted to find Aquarius in the night sky and stare directly at it. But experts suggest relaxing your eyes so you can take in a wider swath of the cosmos.
NASA recommends finding a spot with little to no light pollution—such as a national park, a wilderness area or a certified Dark Sky sanctuary—and either sitting or lying down while facing east.
Once you’ve found your desired observing location, give your eyes 20 to 30 minutes to fully adjust to the darkness, and try to avoid using or looking at any white lights—including your phone screen. Instead, use a flashlight or headlamp with a red light so your eyes stay acclimated, giving you the best chance at spotting meteors.
“My recommendations for this year are the same as for any Eta Aquarid shower—get up around 4 a.m., grab a cup of coffee and lie flat on your back in a dark spot,” says Cooke. “After about 30 minutes, you should start seeing Eta Aqaurids; the rates will increase until the sky brightens with the dawn. The most important thing is not to look at your cell phone, as that destroys night vision and takes your eyes off the sky—don’t expect to see many meteors if you are texting friends and family.”