by Laura S.

Created on: November 11, 2008

Most of us are in awe of lightning. We often sit by the window and watch, as lightning dances across the heaven. But it isnt until the thunder and lightning happen simultaneously that we begin to appreciate the power of our world's electrical forces. Even in this setting, however, the true impact of lightning escapes us. That's because lightning rarely grabs the headlines in the same way as hurricanes, winter storms and tornadoes. Lightning does its work in small numbers and in fractions of a second. However, when it strikes, it really strikes! Lightning is basically a gigantic spark that is an electrostatic discharge. It is much like the spark that occurs when you scuff your sock-footed feet across a carpet, in very dry air, and you touch a doorknob and receive a small shock. The only difference is that the lightning is much, much more powerful. The Earth is jolted by lightning a lot! Each day, about 44,000 thunderstorms occur across the planet, with about 2,000 in progress at any moment. Each second, there are about 100 lightning discharges. But the distribution of lightning across the planet favors tropical and middle latitudes and the land masses that lie in these bands.

Thanks to NASA's space probes, lightning has been detected on other planets in our solar system: the Galileo spacecraft photographed lightning on Jupiter; in 2006, lightning was detected on Saturn thanks to the Cassini spacecraft's radio instruments. The radio equipment "crackled" much like an AM channel has "static" when thunderstorms are nearby.

While the thunderstorm process creates electric charges that then try to group themselves into charge center, the atmosphere acts as a giant insulator, preventing the transfer of electricity and allowing huge amounts of charge to build up. When the strength of the electric field inside and /or near a thunderstorm reaches a critical level, current starts to flow from one charge center toward an opposite charge center. The outcome, lightning, occurs when charge centers connect. In the process, the temporary charge centers in the atmospheric electric filed come into balance and the ionosphoeric- Earth voltage differential is restored. Lightning discharges can occur between a cloud and the ground (or anything on the ground), cloud and air, and inside and between clouds. When lightning occurs inside a cloud or even between clouds, you may not be able to actually see the flash, just the brightening of the cloud. Lightning between a cloud and ground is

• 1
• 2
• Next Page >>