Encyclopedic Entry

Lightning bolts usually carry between 30,000 and 300,000 amperes (amps) of electricity.

Photograph by Vonda Barnett, MyShot

Greased Lightning
Greased lightning is a description for something that is very fast and very powerful. But even the slipperiest substances, like grease, cant be applied to real lightning, of course!

Make Your Own Lightning
The same process that creates lightning is possible to experience at home. Rub your feet on a carpet, then touch a metal doorknob. Do you feel a shock? That's static electricity. Static electricity occurs when an object has too many electrons, giving it a negative charge. The negative charge of your body is attracting the positive charge of the metal in the doorknob. This is a less-dangerous version of the negative charges in a thundercloud attracting the positive charge in the ground beneath.

Imperial Lightning
Lightning strikes New York's Empire State Building about 100 times every year.

Lightning is an electric charge or current. It can come from the clouds to the ground, from cloud to cloud, or from the ground to a cloud.

Lightning is a product of a planet’s atmosphere. Raindrops very high up in the sky turn to ice. When many small pieces of these frozen raindrops collide with each other in a thundercloud, they create an electrical charge. After some time, the entire cloud fills with an electrical charge. The negative charges (electrons) concentrate at the bottom of the cloud. The positive and neutral charges (protons and neutrons) gather at the top of the cloud.

Negative charges and positive charges attract each other. Thunderclouds are full of electrical charges connecting with each other. These connections are visible as lightning.

On the ground beneath the cloud’s negative charges, positive charges build up. The positive charge on the ground concentrates around anything that protrudes, or sticks up—like trees, telephone poles, blades of grass, even people. The positive charges from these objects reach up higher into the sky. The negative charges in the thundercloud reach lower. Eventually, they touch. When they touch, lightning is created between the two charges.

This connection also creates thunder. Thunder is simply the noise lightning makes. The loud boom is caused by the heat of the lightning. When the air gets very, very hot, the heat makes the air explode. Since light travels much, much, faster than sound, you’ll see lightning before you hear thunder. To figure out how far away a storm is, start counting seconds as soon as you see lightning. Stop when you hear thunder. The number you get divided by five is approximately the number of miles away the storm is. For example, if you see lightning and get to 10 before you hear thunder, the storm is about two miles away.

Lightning Safety

All thunderstorms and lightning storms are dangerous. Lightning is very, very hot—hotter than the surface of the sun. It can reach 28,000 degrees Celsius (50,000 degrees Fahrenheit). Lightning likes to strike objects that stick up off of the ground, including people. In the U.S., lightning kills an average of 58 people each year. That’s more deaths than are caused by tornadoes and hurricanes.

If you hear thunder or see lightning, you may be in danger. If you hear thunder, the storm is nearby. Go inside a safe place. Stay away from open areas, like fields, and tall objects, like trees or telephone poles. Stay away from anything metal, too, like chain-link fences, bikes, and metal shelters. Since water is a great conductor of electricity, you should get out of a pool if you’re swimming and stay away from puddles and any other water. If you’re in an area where there is no shelter, crouch low to the ground, but don’t lay down flat. If you’re in a group, stand at least 5 meters (15 feet) from anyone else.

Vocabulary

Term Part of Speech Definition Encyclopedic Entry

atmosphere

Noun

layers of gases surrounding a planet or other celestial body.

Encyclopedic Entry: atmosphere

attract

Verb

to pull toward or cause to unite.

cloud

Noun

visible mass of tiny water droplets or ice crystals in Earth's atmosphere.

Encyclopedic Entry: cloud

concentrated

Adjective

items gathered closely together in one place.

conductor

Noun

material that transfers heat, light, electricity, or sound.

crouch

Verb

to squat or stoop.

current

Noun

steady, predictable flow of fluid within a larger body of that fluid.

Encyclopedic Entry: current

dangerous

Adjective

risky or unsafe.

electric charge

Noun

property of all matter, either positive, negative, or zero.

electricity

Noun

set of physical phenomena associated with the presence and flow of electric charge.

electron

Noun

negatively charged particle in an atom.

Guinness World Records

Noun

yearly reference list of facts and achievements.

hurricane

Noun

tropical storm with wind speeds of at least 119 kilometers (74 miles) per hour. Hurricanes are the same thing as typhoons, but usually located in the Atlantic Ocean region.

ice

Noun

water in its solid form.

Encyclopedic Entry: ice

lightning

Noun

sudden electrical discharge from clouds.

Encyclopedic Entry: lightning

neutron

Noun

particle in an atom having no electrical charge.

planet

Noun

large, spherical celestial body that regularly rotates around a star.

Encyclopedic Entry: planet

proton

Noun

positively charged particle in an atom.

protrude

Verb

to stick out or swell.

raindrop

Noun

drop of liquid from the atmosphere.

static electricity

Noun

motionless electronic charge that builds up on a material.

storm

Noun

severe weather indicating a disturbed state of the atmosphere resulting from uplifted air.

thundercloud

Noun

cloud filled with electricity and capable of producing thunder and lightning.

tornado

Noun

a violently rotating column of air that forms at the bottom of a cloud and touches the ground.

visible

Adjective

able to be seen.

Credits

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Writers

Kim Rutledge
Melissa McDaniel
Diane Boudreau
Tara Ramroop
Santani Teng
Erin Sprout
Hilary Costa
Hilary Hall
Jeff Hunt

Illustrators

Tim Gunther
Mary Crooks, National Geographic Society

Editors

Kara West
Jeannie Evers

Educator Reviewer

Nancy Wynne

Producer

Caryl-Sue, National Geographic Society

Sources

Dunn, Margery G. (Editor). (1989, 1993). "Exploring Your World: The Adventure of Geography." Washington, D.C.: National Geographic Society.

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