The night of February 13, 2014, Indonesia's Kelud volcano burst to life with the ground-rattling energy of some 250 megatons of TNT. Its billowing ash plume shot 16 miles high, sprinkling tiny shards of rock for hundreds of miles.

But that wasn't the only thing the ferocious display had in store: Hundreds of volcanic lightning strokes crackled overhead, spreading their spidery tendrils across darkened skies. Now, scientists say such lightning may be just as useful as it is beautiful. A new study, published in the Journal of Volcanology and Geothermal Research, takes another step toward the development of lightning as a monitoring tool to track the ever-shifting dangers of a volcanic eruption.

“It sort of fills a niche that