Have you ever seen a shooting star, or even a meteor shower?
They’re some of our favorite things to look for in the night sky.
It’s so cool to see the streaks of light!
Meteors happen when pieces of dust or rock in space hit the Earth’s atmosphere — the
air way up in the sky.
They’re going so fast when they hit the atmosphere that they start to get really hot
and burn up!
That’s where the light we see comes from.
[Squeaks squeaks]
Oh, don’t worry Squeaks!
Meteor showers aren’t dangerous.
Once the dust or rock burns up, they're gone.
Meteor showers can look really beautiful, and they’re something special to watch for.
[Squeaks squeaks]
That’s a great question.
Squeaks wants to know what would happen if a much bigger piece of rock hit the Earth.
What would that look like?
Well, Squeaks, that does actually happen sometimes.
If a rock is big enough, not all of it will burn up as it falls through the atmosphere.
Every year, about 30 bigger pieces of rock make it all the way through the Earth’s
atmosphere.
But many of them don’t even hit the ground, and if they do, they usually fall in remote
places or the ocean, so we don’t see them.
Every once in a while, though, people do find pieces of them.
These pieces are called meteorites, and there are some big, cool-looking ones you can see
in museums.
We also know that some huge rocks, called asteroids, hit the Earth a very long time
ago.
Like 65 million years ago, when a very large asteroid hit the Earth.
It was about 10 kilometers, or 6 miles, wide!
It would probably take you about 2 hours to walk that far.
That’s how gigantic it was.
When that asteroid hit Earth, the impact was so powerful that scientists think it caused
the extinction of many dinosaurs.
The asteroid created a giant crater — a hole in the ground shaped like a bowl.
That crater is still there, in Mexico!
And you know what’s covered in craters?
[Squeaks squeaks]
That’s right — the Moon!
The Moon doesn’t have an atmosphere with lots of air like Earth does, so the rocks
that hit it don’t burn up — they get all the way to the surface and make a crater when
they land.
And, since the Moon doesn’t have things like trees or dirt or flowing water to cover
them up, it’s really easy to see all those craters!
[Squeaks squeaks]
Squeaks was wondering if we should be worried about a big asteroid hitting the Earth again
any time soon.
And, it’s really not something to be worried about.
Astronomers, the scientists who study space, use their telescopes to keep track of all
the asteroids nearby.
We know where they’re going in space, and we can tell that none of them will hit the
Earth.
But even though we won’t see a real asteroid impact, do you want to do an experiment to
see how rocks falling from space make craters?
[Squeaks squeaks]
Let’s do it!
All you’ll need are a few things that you probably already have around the house.
To create your own craters, you’ll need:
a baking dish or cookie sheet;
flour;
cocoa powder, or any other kind of powder a long as it’s a different color than the
flour;
a sifter;
and some small, round objects.
We're going to use bouncy balls, but you can use marbles, or even foods like nuts or sunflower
seeds.
If you don't want to make a mess, you can spread out some newspaper or do this experiment
outside.
The first thing we're going to do is add two or three centimeters, or about an inch, of
flour to the baking dish or cookie sheet.
Try to spread it out evenly.
Then, using the sifter, we’ll add a thin layer of the cocoa powder on top of the flour.
These layers are like the surface of the Earth!
The cocoa powder is like the top layer of dirt, and the flour is like the rocks underneath.
Now: assemble your space rocks!
That's what these bouncy balls are for — or whatever you're using as your small, round
objects, like nuts or seeds.
They're going to act like the rocks falling from the sky!
Take one of your space rocks and hold it up about a meter above the flour.
Before you drop it, can you predict what might happen when it makes the impact?
[Squeaks squeaks]
Squeaks thinks the flour will go everywhere!
Let’s see what happens.
3...2...1… impact!
You can see what happens to the surface when the rock hits.
It’s almost like a tiny explosion!
What's left behind is the crater!
Just like the craters here on Earth, or all those craters on the Moon!
You can keep experimenting with different objects from different heights to see what
kinds of craters they make.
If you try this experiment, we'd love to know how it goes!
Ask a grown-up to help you leave a comment below, or send us an email at kids@scishow.com.