Here's what fireballs are and how to best spot them at the Perseid meteor shower's peak
- Viewers of Saturday's Perseid meteor shower could see up to 100 "fireballs" per hour at its peak.
- Fireballs are different from other meteors — they're brighter, rarer, and can audibly "boom."
For meteor-shower enthusiasts, the chance to spot a fireball streak across the night sky is a real treat.
That's because fireballs are just what they sound like — exceptionally brilliant meteors. And of those meteors, the brighter they are, the rarer they are, according to the American Meteor Society.
Luckily for meteor enthusiasts of all ages, the popular Perseid meteor shower, which is set to peak in the early-morning hours of August 13, could feature up to 100 fireballs an hour, Insider previously reported. The AMS has said the phenomenon is rare.
"If you're going to watch any meteor shower this year — because it's going to be the most comfortable and there are going to be lots of fireballs — that's the one to see," Bill Cooke, the lead of NASA's Meteoroid Environments Office at the Marshall Space Flight Center in Huntsville, Alabama, told Insider's Marianne Guenot.
Fireballs are usually a product of large meteoroids that enter Earth's atmosphere. According to NASA, these objects are still not sizable enough to stay intact as they burn up on their descent to Earth, but scientists can sometimes still retrieve meteorites from them.
To be considered a fireball, a meteor — a streak of light caused by a meteoroid that enters Earth's atmosphere — needs to reach magnitude -4, which means it appears brighter than Venus in the night sky, according to the AMS.
The magnitude scale in astronomy categorizes how bright stars appear to humans on Earth, according to EarthSky.org, a site that publishes daily updates on astronomical events on Earth and in our solar system. Lower magnitudes are assigned to brighter celestial bodies.
The light of a fireball can also appear as bright colors, viewers have reported, from reds and blues to yellows and greens — though other burning elements and debris surrounding it can obscure the exact colors of the burning meteoroid itself, according to the AMS.
Vivid fireballs can also produce sounds such as "hissing static, to sizzling, to popping sounds," the AMS said. Even brighter ones can produce a sonic boom.
According to NASA, there are also more intense meteors, referred to as bolides and superbolides, that result from meteoroids or asteroids exploding in the atmosphere.
According to previous reporting from Insider, you have the best chance of seeing the shower in the pre-dawn hours.
This year will be especially good for viewers, Cooke told Insider, because the moon will be at the end of its crescent phase, meaning there will be less light to obstruct viewing in the sky.
Viewers should be sure to give their eyes time — NBC recommends about 20 to 30 minutes — to adjust so you can see the shower most easily.
There are many places to escape the city lights and give yourself a better chance of viewing a fireball — Insider has a list of the darkest places in all 50 US states to watch the stars.