Bonus factismal: Perseids Meteor Shower

If you are up early on Monday morning and see something bright shooting across the sky, don’t be alarmed: it is just part of the annual Perseid meteor shower.

What is a meteor shower?
Meteor showers happen when the Earth’s orbit takes it through the debris of a comet. As comets move closer to the Sun, they heat up and begin to outgas (which means just what it sounds like: they start to give off gas in noxious clouds {like Uncle Joe} and in large jets {like Aunt Sally}). The outgassing also breaks off small chunks of the comet which form a giant debris trail in the sky. Most of these chunks are about the size of a grain of sand, but some can be much larger. When the debris from the comet meets the Earth’s atmosphere, they create the meteor.

These eight images show how much gas is jetted off of a comet in just half an hour! (Image courtesy NASA)

These eight images show how much gas is jetted off of a comet in just half an hour!
(Image courtesy NASA)

The Perseid meteor shower has been linked to the comet Swift-Tuttle. This is one of the oldest and best-known comets. It drops by our neighborhood about every 130 years or so, refreshing the debris field and putting on a spectacular show. Its last pass was in 1992, when it was clearly visible with binoculars. Because its last pass was so recently, the Perseids are one of the more amazing meteor showers with as many as two meteors a minute at the peak.

Where can I see the meteor shower?
Outside.

The best place to see meteor showers is anyplace that is dark and has clear skies. If you live in the city, you might see some of the brighter meteors, but you’ll miss the full glory of the display.

The best place to watch a meteor shower, ever! (Image courtesy NASA)

The best place to watch a meteor shower, ever!
(Image courtesy NASA)

How long is the show?
The Perseids will start late Sunday evening and continue on through Monday. But the peak will happen while North America is facing the Sun, dagnabit. So for all of us on this continent, the best time to see the shower is just before dawn on Monday morning.

The Perseids appear to come from one point in the sky, called the radiant (Image courtesy  Jens Hackmann)

The Perseids appear to come from one point in the sky, called the radiant
(Image courtesy Jens Hackmann)

If you get up between 3 and 5 AM, head outside and face northeast. Stick your fist out at arms length and measure about three fists up; that should put you just above and to the left of the Pleiades. That’s the constellation of Perseus, which is where the meteors appear to come from (which is why they are called the Perseids). Look for a double fuzzy patch; that’s an important part of Perseus and the point that the meteors appear to radiate from (called the radiant).

Meteors are great and all that, but isn’t there some science I can do?
Why, yes there is! If you download NASA’s Meteor Counter App (available for iPad, iPhone, and iWannaMeteor), then you’ll be able to send NASA scientists valuable information on the number of meteors that hit during the shower. They’ll then use that information to help us understand how likely it is that we’ll get hit the way Russia did earlier this year. To get the app, go to the iTunes store:
https://itunes.apple.com/us/app/meteor-counter/id466896415

One thought on “Bonus factismal: Perseids Meteor Shower

  1. Pingback: September 8 – How Thai The Moon | Little facts about science

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