7:15 AM | *Perseid meteor shower peaks late Saturday night/early Sunday morning and it should be a great year for viewing (weather permitting)...a possible brief secondary burst on Sunday night*
Paul Dorian
The Perseid meteor shower will appear to radiate from the Perseus constellation. (Image credit: Future)
Overview
The annual Perseid meteor shower began in mid-July and will continue into late August, but the peak viewing time will be this Saturday night, August 12th, into the early morning hours of Sunday, August 13th. And great news for interested sky observers, this year’s Perseid meteor shower peak will come at a time when the moon will be in the crescent phase minimizing any interference and it won’t even rise until well into the early morning hours on Sunday. Of course, any success for viewing will begin first and foremost with cloud cover and the outlook is somewhat iffy in the Mid-Atlantic with patchy clouds possible as a weak front slides through the region. The Perseid meteor shower comes every July/August as the Earth passes through a cloud of dust that comes from Comet Swift-Tuttle as it approaches the sun. This year’s show could result in as many as 50-75 meteors in an hour for an observer given a dark-sky location and clear skies. One final note, there is the chance for a brief secondary burst of meteors on Sunday night in the 9pm to 10:45pm (ET) time period.
The Perseids happen every year in the July/August time period as the Earth crosses the orbital path of Comet Swift-Tuttle. This comet takes about 133 years to orbit the sun and it last rounded the sun in the early 1990s. Credit Earthsky.org/Guy Ottewell.
Details
Every year, from around mid-July to late-August, our planet Earth crosses the orbital path of Comet Swift-Tuttle, the parent of the Perseid meteor shower. Debris from this comet litters the comet’s orbit, but we don’t really get into the thick of the comet rubble until after the first week of August. Earth's gravity pulls in chunks of small rocks from Comet Swift-Tuttle comprised of iron-nickel, stone, and other minerals. These small rocks turn into bright balls of hot gas when they enter the Earth's atmosphere. As darkness falls, the meteors appear to come from the constellation Perseus, hence the name. The Perseid radiant lies close to the northeastern horizon during the evening hours so the best rates for viewing from North America will be during the early morning hours of Sunday, August 13th when the Perseid radiant lies higher in the sky. With the crescent moon at about 10% illuminated and not even rising until well into the early morning hours, this year’s event should feature very favorable viewing conditions…weather permitting, of course. Typically, the years without moonlight interference see higher rates of meteors per hour and in some of the best outburst years such as in 2016, the rate has been as high as between 150-200 in an hour. In 2022, the Perseids were affected by the full moon illuminating the sky and washing out fainter meteors.
A photo of Perseid meteors seen in 2019 from Macedonia. Courtesy spaceweather.com/Stojan Stojanovski
It is estimated that Perseid meteoroids hit our atmosphere at about 132,000 miles per hour to produce the annual light show and this meteor shower is usually rich in “fireballs” because of the size of the parent comet. Comet Swift-Tuttle has a huge nucleus - about 26 kilometers in diameter - whereas most other comets are much smaller with nuclei only a few kilometers across. Comet Swift-Tuttle has a very eccentric – oblong – orbit that takes this comet outside the orbit of Pluto when farthest from the sun, and inside the Earth’s orbit when closest to the sun. It orbits the sun in a period of about 133 years. Every time this comet passes through the inner solar system, the sun warms and softens up the ices in the comet, causing it to release fresh comet material into its orbital stream. Typically, meteors are only the size of pebbles, some as small as a grain of sand, but Comet Swift-Tuttle produces a large number of meteoroids that are large enough to produce “fireballs”. In fact, the Perseid meteor shower is considered the “fireball champion” of all the annual meteor showers.
One final note, should clouds ruin the opportunity for viewing the Perseids at the peak time of late Saturday night and early Sunday morning or if you simply miss the chance to go outside, there may be another brief window of opportunity on Sunday night for some satisfactory viewing. According to the International Meteor Organization, the Earth will encounter a trail of dust (called a filament) on Sunday, August 13th between 9:00pm and 10:45pm (ET) that was released by the comet in 68 B.C. and this can cause a burst of meteors in this “past peak” time.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com