Skywatchers are preparing for a celestial trifecta: The relatively minor Southern delta Aquariids and alpha Capricornids will set the stage for the impressive Perseids, during which up to 100 meteors will streak across the sky every hour.
Meteor showers occur because pieces of dust and rock are cast off by comets as they circle the Sun at high speeds. When the Earth passes through this debris trail, these small bits of detritus enter our atmosphere and burn up, appearing as blazing lights that streak across the sky.
In the case of the Southern Delta Aquariids, it’s not clear which comet is the source, but it’s believed to be 96P Machholz. The Southern delta Aquariids have actually been underway since July 18 and are set to peak on the night of July 29, according to the American Meteor Society. Unfortunately for those of us north of the equator, as the name suggests, the Southern Delta Aquariids are best seen from the Southern Hemisphere. The meteors are bountiful, with up to 20 visible per hour, but are often faint and lack long trains or explosive fireballs. The presence of a bright Moon can also make them tough to spot. For those who hope to enjoy the show, look toward the southern sky at the constellation Aquarius, which will appear to be the source, or radiant, of the meteors.
As the Southern Delta Aquariids reach their peak and begin to wane, the Alpha Capricornids start to emerge. This shower will have its best night for visibility on July 30. Only around five meteors per hour are expected to be visible from this relatively weak shower. What it lacks in numbers, it makes up for in spectacle, as many of the meteors produce bright fireballs. People in the Southern and Northern Hemispheres will have an equally good view of the shower. To get the best view of the meteors, look towards the radiant: the star Alpha Capricorni in the Capricornus constellation (tip: use a skywatching app on your smartphone to locate celestial objects).
The Southern Delta Aquariids and Alpha Capricornids are a warm-up act for the headliner to come. That’s the Perseids, one of the most popular meteor showers of the year, which will peak on August 11 as the Earth passes through the debris trail of Comet 109P/Swift-Tuttle. As many as 100 meteors per hour will streak across the sky. That night, the Moon will set at around 1 a.m., resulting in a dark sky and enhanced meteor visibility. The radiant for the Perseids is near the Perseus constellation.
For all the meteor showers, the best way to get a good view is to get away from the light pollution of cities and find a nice, dark spot. Lie flat on your back, allow your eyes to adjust to the darkness, look up towards the radiant, and enjoy one of nature’s most spectacular—and free—shows.
