When lightning strikes, it doesn’t just light up the sky — it also shakes things up in space.
A recent study by researchers at the University of Colorado Boulder found that lightning storms on Earth can affect space weather by dislodging high-energy electrons, also known as “killer electrons,” from space around our planet.
These electrons are dangerous because they can damage satellites and harm astronauts.
The research team, led by undergraduate student Max Feinland, used satellite data to discover that lightning storms on Earth can cause bursts of energy that knock high-energy electrons out of the inner radiation belt.
This belt is a region of space filled with charged particles, located hundreds of miles above Earth. These electrons can break through metal, damage satellite systems, and even pose a cancer risk for people in space.
“Our findings show that weather on Earth can impact space in unexpected ways,” Feinland explained.
This discovery could help in protecting satellites and astronauts from harmful radiation. The study, published in Nature Communications on October 8, 2024, shows just how connected Earth and space really are.
Earth has two main radiation belts that are created by its magnetic field: the inner belt, starting around 600 miles above the surface, and the outer belt, which begins roughly 12,000 miles away.
These belts act like shields, trapping charged particles coming from the sun. However, they’re not perfect, and electrons sometimes escape toward Earth.
Researchers have long known that high-energy electrons can fall from the outer belt, but this study is the first to show that the same can happen from the inner belt.
When lightning strikes on Earth, it creates radio waves that shoot up into space. If these waves hit the radiation belts, they can knock electrons loose, much like shaking off raindrops from an umbrella. This process is called “lightning-induced electron precipitation.”
Until now, scientists thought that only low-energy electrons were falling from the inner belt, but Feinland’s work revealed that high-energy electrons are also escaping.
Feinland found this connection by analyzing satellite data and comparing it to records of lightning strikes.
His analysis showed that bursts of high-energy electrons occurred just after lightning strikes, revealing a clear link between the two.
The researchers believe that after a lightning strike, the radio waves trigger a kind of “pinball game” in space, where electrons bounce back and forth between Earth’s northern and southern hemispheres. Each time they bounce, some of these electrons fall into Earth’s atmosphere.
The team plans to continue studying these events to better predict when they might happen, which could help keep satellites and astronauts safe from dangerous radiation.
