A lightning flash stretching 829 kilometres across the skies of Texas has officially been declared the longest-ever lightning bolt recorded on Earth. The record-setting strike, which occurred back in 2017, has just been confirmed by the World Meteorological Organization (WMO) after scientists reviewed satellite data from that massive storm.
When people think of lightning, they usually imagine a bolt striking down from a cloud to the ground. But lightning can also spread horizontally through clouds. These kinds of bolts, called “crawler lightning”, sometimes travel for hundreds of kilometres across storm systems.
When a crawler lightning flash travels an exceptionally long distance, it's called a megaflash.
From the ground, megaflashes don’t look that different. They appear as horizontal flashes of light, but they’re nearly impossible to tell apart from ordinary lightning just by eye. Their true scale is only visible from above , using satellite images.
Although the record-breaking megaflash took place in October 2017, it wasn’t identified until recently, when researchers re-analysed the storm using advanced satellite data. The flash stretched from eastern Texas all the way to near Kansas City – a total distance of 829km, with a margin of error of about 8km.
It beat the previous record of a 768km lightning bolt, also recorded in the southeastern United States.
Megaflashes form when a large chain of storm clouds becomes electrically charged over a wide area. The kind of storm system that causes this is known as a mesoscale convective system – basically, a group of thunderstorms that cluster together and last for hours.
Quite possibly.
This 2017 megaflash was spotted thanks to a new satellite launched by the US National Oceanic and Atmospheric Administration (NOAA). As satellite monitoring improves worldwide, scientists expect even longer lightning flashes might be detected in the future.
Places like Africa, which experience a lot of lightning but lack high-tech observation systems, could be hiding their own megaflash records.
Climate change may also play a role.But it's still too early to say whether megaflashes themselves are becoming more common.
The 829-kilometre megaflash over Texas has stunned scientists and broken all previous lightning records. It shows just how powerful and widespread — a single bolt of lightning can be. Thanks to better satellite technology, we may soon find out that even bigger flashes are happening around the world, possibly in places that haven’t been properly observed yet.
But no matter how fascinating lightning gets, remember: watch it from indoors. It's still one of nature’s most dangerous forces.
