Every minute, on average, about 2,000 thunderstorms are raging on the Earth. These storms collectively generate roughly 100 flashes of lightning every second. These powerful sparks are the result of a sky that’s out of electrical balance—sometimes dangerously so. Lightning is both frequent and global, and it kills or injures more people each year than hurricanes, tornadoes, or blizzards. What is lightning and how does it form? Why is this very common phenomenon one of the least understood natural hazards? And how can you stay safe from the danger and the power of lightning?
Photo courtesy of volunteer Dominic Brady.
Lightning is one of nature’s most impressive and scary sights. One stroke can light up an entire landscape. And when it makes a direct hit on a tree or building it can do incredible damage.
Lightning is both very familiar and very mysterious. It often accompanies rainstorms, especially in warmer climates. Take a closer look, the next time you have the chance. From the safety of your home or car, watch an approaching thunderstorm. When you see a flash, close your eyes right away. You will see the pattern of that lightning. Is it a single, classic jagged bolt? Multiple forked branches? Ribbon-like streamers? A flickering, flash of clouds? A zig and zag across the sky? The variety of patterns is astounding and, to a surprising degree, unexplainable.
The mystery doesn’t end there. New and bizarre forms of lightning have come to light, so to speak, over the last two decades. These electrical phenomena occur high above the Earth, in a region from the stratosphere to the ionosphere. They bear fanciful names that reflect their strange, fleeting behavior and beauty: red sprites, elves, blue jets, trolls, gnomes, and pixies.
To underscore how tricky lightning is to explain in scientific terms, consider that one of the biggest atmospheric mysteries is an ancient one. For centuries, observers have described the sudden, startling appearance of a phenomenon called ball lightning. What is this unpredictable, glowing ball made of and how does it form? Various scientists have advanced theories. Yet no single explanation fits all the observed behavior recorded by hundreds of witnesses through the centuries.
Scientists can’t even fully explain the common, familiar bolts of lightning that just about every human around the globe knows and fears.