Add Yahoo as a preferred source to see more of our stories on Google. A Penn State-led study reveals the hidden chain reaction that starts lightning, linking ...

Scientists have known for decades how lightning travels once it forms, but the exact trigger inside a thundercloud stayed uncertain. A new study now offers the clearest explanation yet for how ...

In a small lab at Penn State University, lightning may be happening on a scale smaller than a deck of cards. Victor Pasko, a ...

Inside a thunderstorm, warm air is forced upward in a strong updraft. As the air rises, ice and water particles collide inside the cloud, creating electrical charges. Those collisions build up ...

What is Lightning?Lightning is a massive electrical discharge caused by imbalances between clouds or between a cloud and the ground. Inside storm clouds, particles collide, separate charges, and build ...

A clear science explanation breaks down how lightning forms and why it branches through the air instead of traveling in a straight line to the ground. The latest: Trump says he’ll hit Iran harder as ...