Perseid Meteor Shower: What You Need to Know

Perseid meteors, like this one seen sailing over the Embudo Valley in New Mexico, are the result of chunks of rocks and particles left behind by the Swift-Tuttle comet. Mike Lewinski [CC by 2.0]/Flickr

The annual Perseid meteor shower, known for its prolific offering of "shooting stars," is expected to be a bit muted in 2019.

Unlike last year (shown below), when there were as many as 80 meteors per hour, the display will be less brilliant this year. The peak of the Perseid meteor shower will occur on the evening of Aug. 12, when skywatchers should be able to see only about 15 to 20 meteors per hour. With the full moon only a couple of days away from the Perseids' peak, views of the meteors will be difficult because of the bright moon's light, reports National Geographic.

The shower officially began on July 17 — when Earth first encountered particles left behind from the comet 109P/Swift-Tuttle — and will persist until Aug. 24. The comet was discovered in 1862, but its ensuing meteor showers have been witnessed for 2,000 years. The shower sometimes creates as many as 200 shooting stars per hour.

When comets enter the inner solar system, they leave behind particles (rock, dust and other assorted debris), and when these particles hit our planet's atmosphere, they heat up — sometimes with brilliant bursts of light. These ill-fated particles travel at 100,000 miles per hour just before they vaporize. The sizes of the meteors range from grains of sand to marbles. If you're lucky enough to catch sight of one of these doomed particles in the act, you've witnessed a shooting star. If the debris doesn't burn up, and it hits the surface, you've got a meteorite.

The odds of seeing shooting stars are best during meteor showers, simply because we know what to expect.

How to see the show

To get the most out of the experience, it's best to find a place far away from the artificial light of cities. The shower can be seen by the naked eye; no fancy equipment is required. Night owls will be happy to know that the pre-dawn hours (after midnight) will offer the best viewing time. Be advised that the moon will be pretty bright this year at 80% illuminated, which may make viewing the meteor shower a little more difficult.

Meteor showers are named after the constellation from which they appear to originate. In this case, it's the constellation Perseus, which is located at latitudes between +90 degrees and -35 degrees and is named after the hero from mythology who killed Medusa.

Aside from this particular light show, there are plenty of other interesting facts to know about the comet behind it. Comet Swift-Tuttle is about 16 miles across, which is roughly the same size as the meteor that caused the extinction of the dinosaurs. There was a scare in the 1990s that Swift-Tuttle would come into contact with the Earth sending us the way of the dinosaurs, but that theory was quickly debunked. However, according to, it's also the largest object "known to make repeated passes near Earth." The comet, last here in 1992, isn't due back until 2126. Fortunately, Swift-Tuttle has left plenty of particles in its wake for our enjoyment in the form of the Perseid meteor shower, proving that one comet's trash is an astronomer's treasure.

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