Space rocks make holes
A very big space rock can hit the ground so hard that it makes a giant round hole. It is called a crater. You can make your own!
- Say what a crater is.
- Make craters with a simple test.
- Say why the Moon has so many craters.
Links to: Working scientifically: performing simple tests and observing closely; maths: measuring length.
What is a crater?
A crater is a big round hole made when a large space rock crashes into the ground. The rock hits so hard that dust and rock fly out in every direction. A ring of rock is left around the edge.
Craters on Earth and the Moon
There is a famous crater in a desert in America called Meteor Crater. It is so big that a whole town could fit inside it.
The Moon is covered in craters. It has no wind or rain to smooth them away, so they last for a very, very long time.
Measuring craters
You drop a marble and make a crater 6 centimetres wide. You drop it from higher up and make a crater 9 centimetres wide. How much wider is the second crater?
- Count on from 6 to 9: 7, 8, 9.
- That is 3 more.
Answer: The second crater is 3 centimetres wider.
With a grown-up, fill a baking tray with flour. Shake a little cocoa powder on top. Drop a marble from low down, then from higher up. Look at the craters. Which is bigger? Can you see the white flour thrown out over the brown cocoa? Measure each crater with a ruler.
Quiz
5 questions. Choose an answer to see whether you are right and why. Finish the quiz to complete the lesson.
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Question 1What is a crater?
A crater is the hole left when a big space rock crashes into the ground.
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Question 2What shape are craters usually?
Craters are usually round, because rock flies out in every direction.
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Question 3Why does the Moon have so many craters we can see?
Craters on the Moon last a very long time because nothing wears them away.
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Question 4In the experiment, what happens when you drop the marble from higher up?
A marble dropped from higher up goes faster and makes a bigger crater.
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Question 5One crater is 5 cm wide and another is 8 cm wide. How much wider is the second?
Count on from 5 to 8: that is 3 more.