Treetops Emit Ultraviolet Sparkles During Thunderstorms. Researchers Just Filmed It in Nature for the First Time

Thunderstorms often illuminate the night sky with flashes of lightning. They also seem to make treetops glow and sparkle—although the phenomenon is pretty much invisible to the naked eye. In a study published February 12 in the journal Geophysical Research Letters, scientists provide the first direct observations of the weak electrical discharges around trees in nature. These outbursts—called coronae—are typically too faint for human eyes to detect. But since they also emit light at ultraviolet.