What is a Meteor Shower?

by Fraser Cain on August 6, 2013


When tiny grains of dust impact our atmosphere, they leave a trail of glowing material, like a streak of light across the sky.

This is a meteor, or a shooting star.

On any night, you can go outside, watch the sky, and be guaranteed to see one. Individual meteors start as meteoroids – pieces of rock smaller than a pebble flying around the Solar System.

Meteor

Geminid meteor shower

Even though they’re tiny, these objects can be moving at tens of thousands of kilometers per hour. When they hit Earth’s atmosphere, they release tremendous amounts of energy, burning up above an altitude of 50 kilometers.

As they disintegrate, they leave a trail of superheated gas and rocky sparks which last for a moment in the sky, and then cool down and disappear from view.

Throughout the year there are several meteor showers, when the number of meteors streaking through the sky increases dramatically. This happens when the Earth passes through the trail of dust left by a comet or asteroid.

Meteor showers are when night sky puts on a special show, and it’s a time to gather your friends and family together and enjoy the spectacle.

Some showers produce only a trickle of objects, while others, like the famous Perseid meteor shower, can dependably bring dozens of meteors each hour.

Meteor Burst  - Credit: NASA

Meteor Burst – Credit: NASA

If the trail is dense enough, we can get what is called a meteor storm. The most powerful meteor storms in history truly made it look like the sky was falling. The Leonids in 1833 produced hundreds of thousands per hour.

Meteor showers take their name from the constellation from where they appear to originate. For example, the Perseids trace a trail back to the constellation Perseus; although you can see them anywhere across the sky.

You can see meteors any time of the year, and you don’t need any special equipment to enjoy an average meteor shower. But here are some ways you can improve your experience.

You’ll want to find a location with as clear a view to the horizon in as many directions as possible. An open field is great. Lie on your back, or on a reclining chair, look up to the sky

… and be patient.

A bright fireball meteor in twilight. The Lyrids, like all meteor showers, offer up the occasional fireball among a mix of fainter meteors. Credit: John Chumack

A bright fireball meteor in twilight. The Lyrids, like all meteor showers, offer up the occasional fireball among a mix of fainter meteors. Credit: John Chumack

You probably won’t see a meteor right away, but after a few minutes, you should see your first one.

The longer you look, the more you’ll see, and the better chance you’ll have of seeing a bolide or fireball; a very bright meteor that streaks across the sky, leaving a trail that can last for a long time.

You can see meteors any time that it’s dark, but the most impressive ones happen in the early morning, when your location on Earth is ploughing directly into the space dust.

You also want the darkest skies you can get, far away from city light pollution, and many hours after the Sun has gone down.

Enjoy the early evening meteors, but then set your alarm and get up around 4 in the morning to see the real sky show.

The radiant for the Persieds, looking to the NE from latitide ~30N at around 2AM local. Created by the Author in Starry Night).

The radiant for the Persieds, looking to the NE from latitide ~30N at around 2AM local. Created by the Author in Starry Night).

If I could only see one meteor shower every year, it would have to be the Perseids. These come when the Earth passes through the tail of Comet Swift-Tuttle, and peak around August 12th every year. It’s not always the most active shower, but it’s warm outside in the Northern hemisphere, and this is a fun activity to do with your friends and family.

Now get outside, and enjoy a meteor shower.

About 

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

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