For the new survey, researchers set up a camera to stare at the same patch of sky above New Mexico for nearly two years. From October 2021 to July 2023, it recorded every light streak that crossed its field of view.
In that time, the camera saw nearly 7,500 meteors. About 850 of them — around one in every eight meteors — left persistent trains. One in 19 meteors left trains lasting more than five minutes.
That was surprising for two reasons. First, way more of the shooting stars left persistent trains than had been expected. Second, the meteors leaving those trains had all sorts of speeds and brightnesses.
Previously, many scientists had held that “these persistent trains were only formed by the fast, bright meteors,” says Logan Cordonnier. He’s an astrophysicist at the University of New Mexico in Albuquerque. “We found that it doesn’t need to be fast,” the new survey’s leader says. In fact, he notes, “Most of the persistent trains were formed by slower meteors.”
All thanks to ozone
The real factor that determined whether a shooting star left a lasting train was ozone, he says.
Meteors that zipped down to altitudes of 90 kilometers were far more likely to leave trains than those that burned up higher in the atmosphere. That key altitude of 90 kilometers is above the
