What are small pieces of rock moving through space called?

Space Rocks: More Than Just Shooting Stars

Space, that big ol’ expanse above us, is chock-full of stuff, from planets and moons to…well, just plain rocks. But these aren’t your garden-variety pebbles; they’re space travelers, zipping around the cosmos. So, what do we call these little wanderers? The answer is meteoroids.

Think of meteoroids as the smaller cousins of asteroids. They’re basically rocky or metallic bits and pieces floating through space. We’re talking about everything from tiny dust specks to chunks about the size of a small car. Anything smaller than that? Those are micrometeoroids, or just plain old space dust.

Where Do These Space Rocks Come From?

Now, where do these meteoroids get their start? It’s a cosmic game of broken pieces and leftovers.

• The Asteroid Belt: This is the big one. Most meteoroids are chips off the old block, broken off from asteroids in that crowded belt between Mars and Jupiter. Imagine a demolition derby, but with space rocks.
• Comets: Remember those icy snowballs with the beautiful tails? As they swing around the Sun, they shed dust and gas. That debris? You guessed it – meteoroids.
• Planets and Moons: Whack a planet or moon hard enough, and you’ll send debris flying. Yep, some meteoroids even come from places like Mars and our own Moon. Talk about long-distance travel!

What Are They Made Of?

These space rocks aren’t all the same. They come in a few different flavors. But almost all meteoroids contain extraterrestrial nickel and iron. Here’s a quick breakdown:

• Stony meteoroids: These are mostly made of silicate minerals, the same stuff you find in a lot of Earth rocks. Some have these cool little grain-like things called chondrules (those are chondrites), and some don’t (achondrites).
• Iron meteoroids: As the name suggests, these are mostly iron and nickel. Scientists think they’re the cores of busted-up asteroids.
• Stony-iron meteoroids: A mix of both! Silicate minerals and iron-nickel alloys all jumbled together.

These rocks are speedy, too. Some of them can zoom around the Sun at something like 26 miles per second near Earth.

From Space Rock to Shooting Star to…Rock?

So, a meteoroid is cruising through space. What happens next? Well, if it wanders into Earth’s atmosphere, things get interesting. That’s when it becomes a meteor. As it plows through the air, it heats up like crazy and creates that bright streak we call a “shooting star”.

Most of these meteors are small and burn up completely – a beautiful, fleeting moment. But if a meteoroid is big enough to survive the fiery plunge and actually reach the ground, we call it a meteorite.

Earth’s Daily Visitors

Get this: an estimated 25 million meteoroids, micrometeoroids, and other bits of space junk enter our atmosphere every single day! That adds up to about 16,535 tons of stuff every year.

Most of it’s tiny and harmless, but every now and then, a bigger one comes along and puts on a real show. And those meteorites that make it to the ground? They’re like time capsules, giving us clues about the history and makeup of our solar system. Pretty cool, huh?