Scientists steer lightning bolts with lasers for the first time

INA – SOURCES
 
Scientists have steered lightning bolts with lasers for the first time in the field, according to a demonstration performed during heavy storms at the top of a Swiss mountain.
 
The feat, which involved firing powerful laser pulses at thunderclouds over several months last year, paves the way for laser-based lightning protection systems at airports, launchpads and tall buildings.
 
“Metal rods are used almost everywhere to protect from lightning, but the area they can protect is limited to a few metres or tens of metres,” said Aurélien Houard, a physicist at École Polytechnique in Palaiseau. “The hope is to extend that protection to a few hundred metres if we have enough energy in the laser.”
 
Houard and colleagues in Switzerland describe how they carted a powerful laser to the top of the Säntis mountain in north-eastern Switzerland and parked it near a 124m-high telecoms tower that is struck by lightning about 100 times a year.
 
The scientists waited for storms to gather and between July and September last year, fired rapid laser pulses at thunderclouds for a total of more than six hours. Instruments set up to record lightning strikes showed that the laser diverted the course of four upward lightning discharges over the course of the experiments.