Sky-watchers around the world are eagerly anticipating the arrival of the annual Perseid meteor shower, which peaks this year from August 11 to 13. And if astronomers’ predictions hold out, the 2016 sky show could present celestial fireworks unlike anything seen in years.
The Perseids grace our skies when Earth plows through a cloud of fragments left behind by comet Swift-Tuttle, which last flew near the sun back in 1992. As the space rock zooms in from deeper reaches of the solar system, its ices vaporize and it releases debris ranging in size from sand grains to boulders. The particles get spread along the comet’s orbital path in such a way that Earth regularly crosses the debris field.
When that happens, the pieces from Swift-Tuttle slam into our atmosphere at speeds of around 100,000 miles (160,000 kilometers) an hour, causing the meteors to burn up and produce momentary streaks across the skies. (Find out how a Japanese company plans to create artificial meteor showers.)
The Perseids rain down from July 17 to August 24, with only a few meteors an hour visible most of the time. However, on peak dates the sky show can produce 60 to 100 meteors an hour.
Expectations are high for an especially vivid display this year because of computer models. Russian astronomer Mikhail Maslov and Finnish astronomer Esko Lyytinen predict that this year Earth will pass through a dense debris field that has been shifted in our direction by Jupiter’s strong gravity.
If we are lucky, this could translate to an intense uptick in shower activity in the late evening of August 11, with rates of up to 200 shootings stars an hour. Observers in North America and Europe should get front-row seats for this possible meteor bonanza, which, if it happens, will be the first Perseid outburst since 2009.
The light from the gibbous moon may drown out a bit of the show during the first part of the night, so the best viewing may be after local midnight and into the predawn hours, when the moon will sink very low in the western horizon.
The meteors will appear to radiate from the shower's namesake constellation Perseus, which rises after local midnight in the northeastern sky.
The best spots to view the shower will be away from the city in the dark countryside. Meteors will be visible even under bright suburban skies, but you can expect to see only a quarter to half as many shooting stars. No matter where you are, allow about half an hour for your eyes to adjust to the darkness before you start sky-watching in earnest.
If you want to get a keepsake of the sky show, try grabbing a photo. All you need is a tripod-mounted digital SLR camera that can take long exposures of 15 seconds or more. Use a wide lens to capture as much of the overhead sky as possible. Set the camera to ISO 400 to pick up fainter shooting stars, and set a remote timer to eliminate any camera shake.
Keep in mind that taking a snapshot of the Perseids involves some patience and luck. It can take many minutes before a single meteor crosses your frame, so experiment with images lasting up to 40 seconds each and keep snapping images for as long as possible.