How to Watch the Southern Delta Aquariids Meteor Shower

If you’re an astronomy aficionado, you might be tempted to skip right ahead to the Perseids, the prolific annual meteor shower that peaks in mid-August. But right now, at least for viewers in the South, another meteor shower is lighting up the night sky: the Southern Delta Aquariids.

These meteors aren’t nearly as plentiful as the Perseids—which is often considered the best meteor shower of the year—but they’re still worth staying up late for. If the Perseids are the hearty main course, consider the Southern Delta Aquariids a tasty appetizer.

The night of July 29 to 30 is the expected peak of the Southern Delta Aquariids, according to the American Meteor Society. But that peak may be difficult to distinguish. Instead, this meteor shower “rambles along steadily from late July through early August,” writes EarthSky.

Peak or no peak, the end of July is still a good time to look for the Southern Delta Aquariids, because the moon will be only partially illuminated. On July 29, it will be in its waning crescent phase, appearing about 30 percent full.

Around this same time, another smaller meteor shower will also be peaking: the Alpha Capricornids. The Alpha Capricornids produce just a few meteors per hour—little more than normal background rates—but they may still increase your odds of spotting a shooting star or two as you watch the sky. And though the Alpha Capricornids are not particularly abundant, they occasionally produce unusually bright meteors known as fireballs.

“Meteors are like nature’s fireworks,” Nick Moskovitz, an astronomer at Lowell Observatory in Flagstaff, Arizona, tells Smithsonian magazine in an email. “They are ephemeral and beautiful. And unlike other phenomena in astronomy, they don’t require any special equipment to observe. A little patience, a clear, dark sky and some luck are all you need.”

If you’re intrigued by the Southern Delta Aquariids, here’s what to know about this often-overlooked meteor shower—and tips for catching a glimpse.

What are the Southern Delta Aquariids?

Like many other meteor showers, the Southern Delta Aquariids occur when Earth passes through a trail of debris left by a comet, leading some of the rocks and dust to get plunged into our planet’s atmosphere. Most of these particles burn up before they can reach the ground, creating streaks of light in the process. At night, some of these fireballs are visible from the ground, and people often refer to them by their nickname, “shooting stars.”

The Southern Delta Aquariids move quickly, traveling at speeds of up to 25 miles per second, or 90,000 miles per hour. That’s fast, but not nearly as zippy as other meteor showers, like the Leonids (160,000 miles per hour) and the Eta Aquarids (148,000 miles per hour).

On the peak of the shower, around 15 to 20 meteors per hour could be visible from Earth in dark conditions, according to EarthSky.

“This is about a factor of two to three times greater than what you would see on a normal night without a meteor shower going off,” says Moskovitz.

A ‘fascinating’ comet

Scientists aren’t totally sure which “comet of origin” left the trail of debris that causes this meteor shower, but they suspect it’s 96P/Machholz, which was discovered in 1986 by amateur astronomer Donald Machholz, according to NASA.

This mystery makes the Southern Delta Aquariids “scientifically very interesting,” says Moskovitz.

“There are open questions about whether 96P really is the parent comet of this meteor shower,” he adds. “Some scientists have suggested that the asteroid 2003 EH1 may instead be responsible.”

Whether 96P/Machholz is the source of the Southern Delta Aquariids or not, it’s a “fascinating object,” says Moskovitz. The comet is 3.7 miles wide—just over half the size of the object that wiped out the dinosaurs—and it orbits the sun every 5.3 years. Using NASA’s Solar and Heliospheric Observatory (SOHO) spacecraft, astronomers recently learned more about 96P/Machholz. The comet has a tail made up of dust and ice,which is typical of comets that pass by the sun. But, in addition to the debris following behind it, 96P/Machholz has a leading debris trail in front of it.

Additionally, 96P/Machholz may be the parent of up to eight other meteor showers throughout the year. It’s known as a “sun-grazing” comet, because it travels much closer to the sun than Mercury does, says Moskovitz. It may also have originated from outside the solar system: Research by Moskovitz’s colleague, astronomer Dave Schleicher, finds that 96P/Machholz’s chemical composition is unusual—unlike nearly any other comet scientists have studied.

The Alpha Capricornids, meanwhile, likely originate from the comet 169P/NEAT. These meteors are “unusually slow” because of the motion of the comet and its debris trail relative to Earth, says Moskovitz. Their sluggishness, coupled with the higher-than-average chance of fireballs, means “lucky observers may get to see a particularly spectacular meteor,” he adds.

Today, the Alpha Capricornids are considered a minor meteor shower. But because the debris trail that leads to this shower is gradually moving in space, that may change someday.

“There are predictions that in about 300 years the [Alpha Capricornids] shower may become one of the major annual meteor showers,” says Moskovitz. “So, mark your calendars now for summer 2324.”

Tips for viewing the Southern Delta Aquariids

While the spectacle is most easily seen from the Southern Hemisphere, the Southern Delta Aquariids can still put on a show for Northern Hemisphere skygazers. In the United States, they’re most visible from southern states.

As you look up, keep an eye out for glowing streaks of light that seem to last a long time—these are known as “persistent trains,” and roughly 5 to 10 percent of Southern Delta Aquariids meteors have them, according to EarthSky.

You’ll have the best chances of viewing the Southern Delta Aquariids from a location with very little light pollution. State parks, national forests, national parks and other protected landscapes are often your best bet. If you have a certified “dark sky” place near you, head there.

Pack a lawn chair so you can lean back and look up, or a blanket for lying on the ground. Once you arrive at your viewing location, try not to look at your phone screen or any other bright lights for at least 15 minutes to give your eyes a chance to acclimate to the dark. If you’ll be moving around, use a headlamp or flashlight with a red beam.

To Earth-bound observers, the Southern Delta Aquariids appear to be coming from the constellation Aquarius, a point in the sky known as their “radiant.” More specifically, they look like they’re originating from the third-brightest star in the constellation, Delta. But you don’t need to stare directly at the constellation—in fact, experts say you’ll have the best viewing experience if you keep your gaze wide. Since the shower is most visible from the Southern Hemisphere, however, it’s helpful to go somewhere with a view of the southern horizon, says Moskovitz.

“The Southern Delta Aquariids meteors will appear to be radiating towards the north, west and east from the southern horizon,” he says.

Around 2 a.m., the radiant will be highest, making the meteors appear higher in the sky. But trying to catch a glimpse in the hour before and after midnight—before the moon rises—might offer clearer viewing, writes LiveScience’s Jamie Carter.

“The most important thing is to find a dark spot,” says Moskovitz. “Get away from streetlights, house lights and traffic. Put away your cellphone. Get comfortable, and be patient.”

Sarah Kuta | READ MORE

Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.