Scientists have recently captured images of a rare weather phenomenon known as corona discharge, which occurs during thunderstorms. This faint glow, visible on treetops, is caused by weak electrical sparks forming on the tips of leaves when a thunderstorm's electric field intensifies. Researchers from Penn State used a specialized UV camera to detect these discharges, which are significant enough to alter the air's chemistry by producing hydroxyl radicals that help clean pollutants. The study, published in Geophysical Research Letters, confirms long-held suspicions about the existence of these discharges, which are nearly invisible to the naked eye but play a crucial role in atmospheric processes.