Brazilian Scientists Capture How Lightning Rods Attract Bolts

Lightning rod is one of the most important inventions for human kind. As we construct more and highrises, the copper or aluminum rod set above the highest point of a building protects the structures from the extremely high currents produced by lightning. A lightning rod is connected to the ground through wires that take the current to the ground. But less than a millisecond before lightning touches it, the rod, induced by the negative charge of the lightning, send a positive discharge to connect to it. It is very rare to capture the moment but two Brazilian scientists have done just that.

Marcelo Saba and Diego Rhamon are going viral for capturing the 'Thor moment' on camera. Their unique image of lightning strikes shows details of the connections to nearby buildings.

While Saba is a researcher at Brazil's National Space Research Institute, Rahmon is a PhD candidate.

Armed with a high-speed video camera with a high resolution, they captured the electric action in Sao Jose dos Campos, a city northeast of Sao Paulo.

"The image was captured on a summer evening in Sao Jose dos Campos while a negatively charged lightning bolt was nearing the ground at 370 km per second. When it was a few dozen metres from ground level, lightning rods and tall objects on the tops of nearby buildings produced positive upward discharges, competing to connect to the downward strike. The final image prior to the connection was obtained 25 thousandths of a second before the lightning hit one of the buildings," Saba told Scienmag.

The researcher explained that the camera he used takes 40,000 frames per second.

The spectacular image was featured on the cover of December 2022 issue of Geophysical Research Letters (GRL), a leading scientific journal.