WEBVTT - How Big Does a Meteoroid Have to Be to Make It to the Ground?

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<v Speaker 1>Welcome to brain Stuff, a production of iHeartRadio, Hey brain

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<v Speaker 1>Stuff Lauren Vogal bomb here. Meteor showers are spectacular, but

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<v Speaker 1>one of the most amazing things about these displays is

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<v Speaker 1>that the majority of the space debris that causes visible

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<v Speaker 1>meteors is tiny, between the size of a grain of

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<v Speaker 1>sand and the size of a small pebble. Discussing meteor

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<v Speaker 1>activity can be tricky because the terminology is a little confusing.

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<v Speaker 1>The term meteor actually refers to the streak of light

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<v Speaker 1>caused by a piece of space debreed burning up in

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<v Speaker 1>the atmosphere. The pieces of debris are called meteoroids, and

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<v Speaker 1>the remnants of the debris that reach Earth's surface or

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<v Speaker 1>the surface of other planets are called meteorites. Meteoroids come

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<v Speaker 1>in a pretty wide range of sizes. They include any

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<v Speaker 1>space to breed bigger than a molecule and smaller than

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<v Speaker 1>a hundred meters in diameter that's about three ft. A

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<v Speaker 1>space debreed bigger than this is considered an asteroid. But

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<v Speaker 1>most of the debris that Earth comes in contact with

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<v Speaker 1>is dust shed by comets traveling through the Solar System.

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<v Speaker 1>This dust tends to be made up of very small particles,

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<v Speaker 1>so how can we see a meteor caused by such

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<v Speaker 1>a tiny bit of matter? What these meteoroids black and mass?

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<v Speaker 1>They make up foreign speed, and this is what causes

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<v Speaker 1>the flash of light in the sky. Meteoroids enter the

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<v Speaker 1>atmosphere extremely high speeds a seven to forty five miles

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<v Speaker 1>per second, that's about eleven to seventy two kilometers per second.

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<v Speaker 1>They can travel at this rate very easily in the

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<v Speaker 1>near vacuum of space because there's not a lot to

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<v Speaker 1>stop them. Art's atmosphere, on the other hand, is full

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<v Speaker 1>of matter, which creates a great deal of friction on

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<v Speaker 1>a traveling object. This friction generates high heat up to

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<v Speaker 1>three thousand degrees fahrenheit or one thousand, six hundred degrees celsius,

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<v Speaker 1>and can raise the meteoroids surface to its boiling point

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<v Speaker 1>so that the meteoroid is vaporized layer by layer. The

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<v Speaker 1>friction breaks the molecules of both the meteoroid material and

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<v Speaker 1>the atmosphere into lowing ionized particles, which then recombine, releasing

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<v Speaker 1>light energy to form a bright tail. A meteor tail

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<v Speaker 1>caused by a grain sized meteoroid will only be a

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<v Speaker 1>few feet wide or about a meter, but because of

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<v Speaker 1>the high speed of the debris maybe many miles long.

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<v Speaker 1>So how big does a meteoroid have to be to

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<v Speaker 1>make it to the surface of the Earth. Perhaps surprisingly,

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<v Speaker 1>most of the meteoroids that reach the ground are especially small,

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<v Speaker 1>from microscopic to dust particle sized pieces. They don't get

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<v Speaker 1>vaporized because they're light enough that they slow down pretty easily.

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<v Speaker 1>I'm moving in a mirror one inch or two and

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<v Speaker 1>a half centimeters per second through the atmosphere. They don't

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<v Speaker 1>experience the intense friction that larger meteoroids do. In this sense,

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<v Speaker 1>most all meteoroids that enter the atmosphere make it to

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<v Speaker 1>the ground in the form of microscopic dust, as four

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<v Speaker 1>meteoroids that are big enough to form visible meteors. Estimates

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<v Speaker 1>for the minimum size vary. This is because there are

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<v Speaker 1>factors other than size involved. Most notably, a meteoroid's entry

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<v Speaker 1>speed affects its chances of reaching the surface because it

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<v Speaker 1>determines the amount of friction the meteoroid experiences. And typically,

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<v Speaker 1>though a meteoroid would have to be about the size

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<v Speaker 1>of a marble for a portion of it to reach

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<v Speaker 1>the Earth's surface, smaller particles burn up in the atmosphere.

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<v Speaker 1>The meteorites a person is likely to find on the

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<v Speaker 1>ground probably come from significantly larger meteoroids, pieces of debris

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<v Speaker 1>at least the size of basketball, typically because larger meteoroids

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<v Speaker 1>usually break up into smaller chunks as they travel through

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<v Speaker 1>the atmosphere. Estimates of how much space debris false to

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<v Speaker 1>Earth very widely. Researchers have looked at everything from polar

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<v Speaker 1>ice cores to the composition of the atmosphere to try

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<v Speaker 1>to ssess it out. Studies from the past few years

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<v Speaker 1>have indicated that as much as sixty tons of space

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<v Speaker 1>dust and tiny rocks might make impact every day, which

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<v Speaker 1>means that chances are decent that you can find some

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<v Speaker 1>in your own backyard. You can try putting out a

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<v Speaker 1>pan on a clear or day or night, or looking

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<v Speaker 1>for tiny rocks near the outlet of rain gutter pipes.

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<v Speaker 1>A strong magnet will pick up potential micro meteorites. Of course,

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<v Speaker 1>some normal earth stuff will latch onto a magnet too.

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<v Speaker 1>You can tell micro meteorites apart because they'll be spherical,

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<v Speaker 1>and if you look at them under a microscope, they'll

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<v Speaker 1>have a glassy crusting formed during their fiery fall. Today's

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<v Speaker 1>episode was written by somebody on the house Stuff Works

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<v Speaker 1>team in the Way Back and produced by Tyler Clang.

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<v Speaker 1>For more in this and lots of other topics, visit

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