Several times a year, as Earth careens around the solar system, it passes through rocky, icy particles, some as small as a grain of sand. These particles may then collide with our atmosphere, lighting up in our sky as they burn into oblivion.
This is what we earthlings know as a meteor shower, and perhaps the most well-known of this phenomenon is the Perseid meteor shower. The Perseids, named for where they appear to originate in the sky, put on a multicolored light show from mid-July into mid-August every year.
What is the Perseid meteor shower?
The pieces of rock and ice that make up the Perseid meteor shower were once part of the Swift-Tuttle comet, which is visible from earth every 133 years. As this comet circles around the sun, it leaves a trail of remnants. Earth then passes through these bits and pieces of rock and ice during its orbit. When one of these bits enters the atmosphere, it gets extremely hot, creating the trailing meteor that we can see from the ground.
“These little particles — and they can be very small, like pea-sized — but they'll create spectacular light shows in the sky, because they're coming in at a very, very fast speed,” said Terri Zittritsch, president of the Vermont Astronomical Society. “The Earth's moving through space very fast. This material is moving very fast, and it will come in through the atmosphere and basically get very hot and disintegrate and create this light show across the sky.”
It may seem impossible that you can see something as small as a grain of sand from 60 miles away, but the combination of speed and the resulting heat results in a bright glow, sometimes in different colors like green or yellow. These particles, and the comets they were originally part of, are also some of the oldest bits of rock and ice in our solar system: They’re about 4.5 billion years old, said Jim Cooney, an astrophysicist at the University of Vermont who studies cosmology and hosts the astronomy podcast Walkabout the Galaxy.
”Comets are old things, right? They're things that formed at the very beginning of our solar system. … And so these little pebble-sized things entering our atmosphere are 4.5 billion-year-old pieces of ice that you're getting to see burn up in their last great gasp,” Cooney said.
These particles, Cooney said, are much older than any rock you might find on Earth. “This is the stuff of our creation.”
How to see the Perseid meteor shower
This year, the meteor shower’s peak is Aug. 12-13, just after the full moon on Aug. 9.
The timing of the full moon complicates things for folks hoping to see the meteor shower at its peak, which is when meteor sightings are the most plentiful. During this time, you can see anywhere from 50-100 meteors an hour.
However, “light’s the enemy of any kind of stargazing, or, in this case, meteor showers,” Zittritsch said.
The light from the waning moon will make the smallest meteors less visible. That’s why both Zittritsch and Cooney recommend going out on a clear night sometime in the next week or two for the best viewing conditions.
There’s also another great reason to head out now, toward the beginning of the event: fireballs.
“Kind of early in the meteor shower, you might see some really nice, big fireballs, which are the bigger chunks,” Cooney said. “They may kind of just graze the Earth's atmosphere. So they might last longer and they're higher in the atmosphere. And those things can be colorful and awesome.”
Fireballs are the astronomical term for large meteors that can look, literally, like a big fireball in the sky. He said the best time to look for them is toward the beginning or end of a meteor shower event — so in this case, now through the beginning of August, and again toward the end of the Perseid event on Aug. 24.
For the best viewing, you’ll want to head out of town and away from any light pollution. The best time to see meteors is in the early morning hours, anytime after midnight and before dawn.
“So, going to somewhere, you know, a field, someplace where you don't have a lot of man-made lighting is the best,” Zittritsch said. And try to ensure you have a wide view of the sky.
You can lie down on a blanket or set up a comfortable chair facing north, toward the constellation Perseus, which is the area in the sky where the meteors appear to come from.
Allow your eyes about 30 minutes to adjust to the dark, and avoid looking at your phone.
It’s important to have a little patience, but both Zittritsch and Cooney assure that you won’t be disappointed.
“If you go out to a dark spot and sit up and stare at the sky for an hour, you're going to see a good, decent number of meteors,” Cooney said.
And, most importantly, enjoy the show.
Looking for a viewing spot on Monday, July 28? Vermont Public has you covered. You can register for our Eye on the Sky Stargazing Party at Sugarbush with Mark Breen and Jane Lindholm for a night full of stars, planets and meteors.
