Welcome to brain Stuff from house Stuff works dot com, where smart happens Him Marshall Brain with today's question, how big does a meteor have to be to make it to the ground. If you've spent much time looking up at the night sky, you've probably seen some spectacular meteors and meteor showers. One of the most amazing things about these displays is that the majority of the space does that causes visible meteors is tiny, between the size of a grain of sand and the size of a small pebble.
Discussing meteor activity can be tricky because the terminology is pretty confusing. The term meteor actually refers to the streak of light caused by a piece of space debris burning up in the atmosphere. The pieces of debris are called meteoroids, and remnants of the debris that actually each Earth's surface or another planets for that matter, are called meteorites. Meteoroids have a pretty big size range. They include any space debris bigger than a molecule and smaller than about three
thirty feet or a hundred meters in diameter. Space debris bigger than this is considered an asteroid, but most of the debris the Earth comes into contact with is dust shed by comets traveling through the Solar System. This dust tends to make up the small particles that we see as meteors. So how can we see a meteor caused by such a small bit of matter. It turns out that what these meteoroids lack in mass, they make up for in speed, and this is what causes the flash
of light in the sky. Meteoroids enter the atmosphere at extremely high speeds seven to forty five miles per second or eleven to seventy two kilometers per second. They can travel at this rate very easily in the vacuum of space because there's nothing to stop them. Earth's atmosphere, on the other hand, is full of matter, which creates a
great deal of friction on the traveling object. This friction generates enough heat up to three thousand degrees fahrenheit or degrees celsius, to raise the meteoroid surface to its boiling point, so the meteoroid is vaporized layer by layer. The friction breaks the molecules of both the meteoroid material and the atmosphere into glowing ionized particles, which then recombine, releasing light energy.
To form a bright tail. A meteor tail caused by a grain sized meteoroid is a few feet wide about a meter, but because of the high speed of the debris, maybe many miles long. So how big does a meteoroid have to be to make it to the surface of the Earth. Surprisingly, most of the meteoroids that reach the ground are a specially small, from microscopic debris to dust
size particle pieces. They don't get vaporized because they're light enough that they slow down very easily, moving about one inch or two and a half centimeters per second through the atmosphere. They don't experience the intense friction that larger meteoroids do. In this sense, most all meteoroids that enter the atmosphere make it to the ground in the form of microscopic dust. As for the meteoroids big enough to form visible meteors, estimates for the minimum size vary. This
is because there are factors other than size involved. Most notably, a meteoroid's entry speed affects its chances of reaching the surface because it determines the amount of friction the meteoroid experiences. Typically, though a meteoroid would have to be about the size of a marble or a portion of it to reach the Earth's surface. Smaller particles burn up in the atmosphere
about fifty seven five miles above the Earth. The fist size meteorites a person is likely to find on the ground probably came from something significantly larger pieces of debris at least the size of a basketball. Since larger meteoroids usually break up into smaller chunks as they travel through the atmosphere, you can actually find and collect tiny meteorites that have made it through the Earth's atmosphere. With this simple experiment, put a pan on your back porch or
deck and catch them. You can find sites on the web that will show you how to identify the difference between meteorites and bits of sand and dust. For more illness and thousands of other topics. Does that how stuff works dot com and don't forget to check out the brain stuff blog on the house stuff works dot com home page. You can also follow brain stuff on Facebook or Twitter at brain stuff HSW. The house Stuff Works I fine app has arrived down at it today on iTunes, m