The Eta Aquarid meteor shower peaks Tuesday night into Wednesday morning this week, but skywatchers hoping to catch a dramatic show of shooting stars will face interference from a bright, nearly full moon. The waning gibbous moon is expected to be 84% full at the time of the peak, washing out the fainter meteors and making the display harder to appreciate with the naked eye.
“For us in the Northern Hemisphere, it’s not going to be as impressive,” said Teri Gee, manager of the Barlow Planetarium in Wisconsin. “The farther south you are, the better you’ll see it.”
Under ideal dark-sky conditions, viewers in the Southern Hemisphere can typically see around 50 meteors per hour during the Eta Aquarid peak. This year, astronomers estimate the interfering moonlight will cut that number roughly in half. In the northern sky, the display will be sparser still — likely fewer than 10 meteors per hour.
The Eta Aquarids are one of two annual meteor showers produced by debris from Halley’s comet, the other being the Orionids in October. Halley’s comet orbits the sun roughly every 76 years. Its last close approach to Earth was in 1986, and it will next swing by in 2061. As Earth charges through the trail of particles the comet left behind, those bits collide with the atmosphere at extremely high speeds, producing the bright streaks known as shooting stars.
“Meteor showers happen when the Earth charges through trails of debris left behind from comets or asteroids,” explains the underlying astronomy. On a typical night, only a handful of stray meteors appear. During a shower like the Eta Aquarids, the rate climbs to a more dramatic display — provided the sky is dark.
To make the most of the compromised viewing conditions, astronomers recommend heading outside just before dawn, when the shower’s radiant point — near the constellation Aquarius and the bright star Eta Aquarii — is highest in the sky. Getting away from city lights and tall buildings is essential. For this particular shower, finding a spot where a building or hill blocks the moon itself can help darken the view.
“You’re looking for bright streaks that appear in the corner of your eye for a fraction of a second,” said astrophysicist Nico Adams of SSP International, a nonprofit that promotes STEM education. He advised viewers to avoid looking at their phones and to give their eyes time to adjust to the darkness.
Gee emphasized that even a diminished meteor shower rewards patience. “It almost feels like you’re discovering it yourself,” she said, adding that there is no better way to enjoy the display than to experience it firsthand, with blankets and lawn chairs in a dark spot under the open sky.