Three Key Takeaways:
- Scientists discovered gamma rays emitted by thunderclouds, offering a new clue about how lightning forms, challenging previous theories.
- The “electron avalanche” theory, which suggests lightning is initiated by high-energy electron collisions, is gaining traction after this discovery.
- The research, involving a Cold War-era spy plane and laboratory experiments, is pushing the boundaries of lightning science, revealing its extreme complexity.
Lightning strikes Earth a staggering 3 million times every day.
Yet scientists are still baffled by how it actually forms.
And researchers just uncovered a shocking new clue that turned everything we thought we knew upside down.
Mysterious gamma rays may hold the key to unlocking lightning’s secrets
For centuries, scientists have been trying to solve one of Earth’s oldest mysteries – how lightning starts. Despite all our technological advances, we still don’t fully understand this awe-inspiring phenomenon that flashes across our skies 44 times every second.
When Benjamin Franklin flew his famous kite experiment in 1752, he proved lightning was electrical. But that was just the beginning of the puzzle, not the end.
“It’s happening up in a cloud, which is a very hostile place,” says Professor David Smith from the University of California, Santa Cruz. “And in the moments before a strike, when lightning is forming, it’s shrouded from sight by clouds.”
The problem that has stumped researchers for decades is that air is an excellent insulator. It doesn’t readily conduct electricity. Scientists have calculated the electric field strength needed to overcome this insulation and create lightning – but when they measure the electric fields inside actual thunderclouds, they don’t come anywhere close.
“You’ve got millions of lightning flashes a day and yet you never seem to see an electric field big enough to actually make a spark,” explains Joseph Dwyer, professor of physics and astronomy at the University of New Hampshire. “It’s one of the biggest mysteries in the atmospheric sciences.”
Cold War spy plane makes startling discovery
In 2023, Norwegian researchers took a bold new approach to cracking this mystery.
Using a retrofitted Cold War-era spy plane, they flew at the incredible altitude of 20km (65,000ft) – about 6km higher than any previous lightning research mission.
What they found stunned the scientific community.
The team discovered an enormous thundercloud that was emitting gamma rays – extremely high-energy radiation more typically associated with supernovas and cosmic events – that pulsated across thousands of square kilometers for hours.
“It’s not uniformly glowing. It’s like a boiling pot,” says Professor Nikolai Østgaard, a space physicist at the University of Bergen who led the research.
Even more remarkably, they identified an entirely new phenomenon they called “flickering gamma-ray flashes” – something never before observed that seems to be directly linked to lightning activity.
“After these flickering gamma-ray flashes, there was intense lightning activity,” Østgaard revealed.
The electron avalanche theory
This discovery strongly supports a theory that many lightning scientists have been developing – that lightning may be initiated by what they call an “electron avalanche.”
According to this hypothesis, the electric field within a thundercloud accelerates free electrons to nearly the speed of light. These supercharged electrons crash into atoms in the cloud, knocking loose more electrons and creating “an avalanche of high-energy particles,” as Smith describes it.
Computer modeling suggests that when these electrons collide with air molecules, they create positrons – the antimatter equivalent of electrons. These positrons then generate even more electron avalanches, creating a feedback loop that might finally explain how lightning begins.
The process is like “stepping on a bump in the carpet. You can push it down in one place, but then it pops up someplace else,” Dwyer explains.
Laboratory lightning reveals extreme dangers
Scientists aren’t just studying lightning from the sky – they’re also creating it in specialized laboratories.
“The advantage of using a laboratory is that it’s very controllable and repeatable,” says Dr. Daniel Mitchard, a particle physicist at Cardiff University’s Lightning Laboratory.
But artificial lightning is just as destructive as the real thing.
“You can’t look at it because it’ll blind you. You have to wear ear protection, because we also produce the thunder – and it’s all within a shielded room,” Mitchard warns.
The quest continues
Spurred by their groundbreaking findings, Østgaard and his team are already planning their next mission. They plan to equip the spy plane with even more sensitive instruments to better understand the link between the flickering gamma-ray flashes and lightning formation.
While we’re getting closer to understanding one of nature’s most spectacular displays, the mystery of lightning continues to deepen with each new discovery.
But one thing is certain – lightning is far more complex and fascinating than scientists ever imagined. What we once thought was simply electricity jumping between clouds and ground turns out to involve antimatter, cosmic rays, and physics phenomena we’re only beginning to understand.
The next time you witness a lightning storm, remember that you’re watching one of Earth’s oldest mysteries unfold – one that continues to baffle even our brightest scientific minds.