Spectacular meteor show peaking soon in Shelter Island skies

Get ready to stay up late and stare at the sky. The annual Perseid meteor shower runs from July to September, but this year the celestial display peaks on the nights of Aug. 11 and 12.

This is one of the best meteor showers of the year, with the potential for 100 meteors per hour. John Denver’s song “Rocky Mountain High” references the showers with the lyric, “I’ve seen it raining fire in the sky.”

The Perseid meteor shower is a result of Earth passing through the debris field of comet 109P/Swift-Tuttle.

The comet was independently discovered by Lewis Swift on July 16, 1862, and by Horace Parnell Tuttle on July 19, 1862. It is a Halley-type comet, meaning that it orbits the sun between every 20 to 200 years. This comet orbits every 133 years, leaving behind a trail of icy debris ranging in size from a grain of sand to peas and even marbles.

Comet Swift-Tuttle is the largest object known to make repeated passes near Earth. Its nucleus is about 16 miles across, roughly equal to the object that wiped out the dinosaurs. Don’t fret, however; calculations have determined that its next closest pass will put it about a million miles from Earth in the year 3044.

Perseid meteoroids are anywhere from 60 to 100 miles apart, even at the densest section in the river of comet debris. They enter Earth’s atmosphere as meteors at roughly 133,200 miles per hour. Almost none hit the ground, as most Perseids burn up in the atmosphere at heights above 50 miles.

For the best viewing, Steven Bellavia of the Custer Institute and Observatory in Southold recommends waiting until the wee hours. “After midnight is ideal, as the waxing crescent moon will have set, and that is also when the ‘windshield’ — where you are on Earth, looking up — is facing the direction of our [rotation], which makes the meteors more visible than glancing blows from the sides.”

The meteors will mostly appear to radiate from the constellation Perseus — hence the name — in the Northwest sky near Cassiopea (aka the crooked W) but the wider the viewing field the more will be visible, so be prepared to look in all directions.