Why Is the Moon Scarred with Craters?

Why does the Earth have fewer craters than the moon?

• The Earth has a stronger gravitational field and attracts more debris than the moon.

• The Earth is bigger than the moon.

• The Earth has processes that can erase almost all evidence of past impacts. The moon does not.

• The moon attracts fewer bits of space rock than the Earth.

What does this passage describe?

• This passage describes the three processes that help Earth keep its surface crater free.

• This passage describes the dusty footsteps of astronauts that you can still see on the moon today.

• This passage describes the 180 craters that you can still see on Earth.

• This passage describes the way volcanism covers up craters everywhere in our solar system.

Read these sentences from the text:

"Three processes help Earth keep its surface crater free. The first is called erosion. Earth has weather, water, and plants. These act together to break apart and wear down the ground. Eventually erosion can break a crater down to virtually nothing."

What can be concluded about Earth's surface based on this information?

• Earth's surface looks exactly the same as the moon's surface

• Earth's surface is constantly changing

• Earth's surface has been the same for thousands of years.

• Earth's surface will eventually be completely smooth.

Based on the information in the text, what do you think would happen to Earth's surface if erosion, tectonics, and volcanism suddenly stopped occurring?

• Earth would continue to erase evidence of past impacts.

• Earth would have fewer craters.

• Earth would stop erasing evidence of past and future impacts.

• Earth would be completely smooth.

What is the main idea of this text?

• Tectonics are processes that cause our planet’s surface to form new rocks, get rid of old rocks, and shift around over millions of years.

• The process of erosion uses weather, water, and plants to break down the ground on earth so that craters become virtually nothing.

• The Earth's gravity is stronger than the moon's, so it attracts more space debris than the moon does.

• Unlike the Earth, the moon does not have processes that remove craters from its surface.

Read the following sentences from the text:

"Three processes help Earth keep its surface crater free. The first is called erosion. Earth has weather, water, and plants. These act together to break apart and wear down the ground. Eventually erosion can break a crater down to virtually nothing."

As used in the passage, what does the word "process" mean?

• a way of thinking

• a set of changes that happen one after another

• a shield that Earth uses to protect itself from craters

• a way of moving forward

Choose the answer that best fits the sentence.

Once something hits the moon, that event becomes frozen in time. ________, Earth simply brushes these impact craters off and moves on with its life.

• for example

• therefore

• in contrast

• including