There’s an Earth-based mystery recently solved. It involves lightning. Specifically, a particular transient luminous event (TLE) called a blue jet. We’ve seen them from the ground a few times, but like most TLEs, they are rare. However, it’s important to understand what causes these events because electrical bursts can affect radio waves and impact communication.

Instruments on the International Space Station (ISS) spotted a blue jet in February 2019, and the results were published this week in the journal Nature. The jet occurred during a storm over the Pacific Ocean near the island of Nauru, and cameras and photometers managed to collect data from the event. It started with what is described as a “blue bang” by lead author Torsten Neubert. The bang was a flash of blue light about 10-microseconds long that occurred near the top of the storm clouds, nearly 16 kilometers in altitude. A blue jet then shot up from that flashpoint, reaching nearly 52 kilometers and only taking a few hundred milliseconds to do so. Hence why collecting data on these TLEs is so difficult; not only are they rare to begin with, they are also brief.

Neubert goes on to explain that “turbulent mixing high in a cloud may bring oppositely charged regions within about a kilometer of each other, creating very short but powerful bursts of electric current.” We have detected such bursts with ground-based antennae, and it’s nice to piece together all the evidence. One mystery solved.

More Information

Science News article

“Observation of the onset of a blue jet into the stratosphere,” Torsten Neubert et al., 2021 January 20, Nature