On a clear night, the moon shines brightly overhead. You might think that the moon gives off light, 

but it does not. Light from the sun reflects off the moon’s surface. Sometimes the moon looks like a large ball steady in the sky. Other times it looks like a tiny sliver. Myths, or legends, were made up by early people to explain why the moon changes shape. The early people of Greenland thought the sun goddess was chasing her brother, the moon god, across the sky. Greenland is an island in North America. The moon god ran so much that he forgot to eat, so as days passed, he became thinner. Finally, the moon god had to stop and eat. He got bigger, and the chase began all over again. Today people understand why the shape of the moon changes. The changes in the shape of the moon are caused by the way the moon moves in space. The moon moves in two ways. It rotates, or spins around like a top. It takes the moon about twenty-nine days to rotate once. It also travels in a path around the earth called an orbit. The different shapes of the moon are called phases. This is what the phases of the moon look like:

full

waxing gibbous

half moon

waning

waxing

The phases of the moon in orderare: 

full, 

waning gibbous,

 half moon,

crescent, 

new moon,

 waxing crescent,

half moon, 

waxing gibbous, 

and full.

gibbous

crescent

half moon

new

crescent

The moon takes about twenty-nine days to orbit around the earth. The sun always lights up half of the moon. We do not always see the lit-up half from the earth. When you see all the lit-up half of the moon, the moon appears to be a full circle. This is called the full moon. As the moon travels around the earth, we see less and less of the lit part. This is called the waning moon. Soon the lit-up part of the moon disappears from sight. This is called the new moon. Then the moon starts to look lit up again, and the lit part that you see gets bigger each day. This is called the waxing moon. It takes about twenty-nine days for all the phases. That’s the same amount of time it takes for the moon to make one

trip around the earth. Starting in the 1950s, spacecraft were sent to study the moon. The spacecraft orbited the moon. In this way, scientists learned more and more about the moon. Then, on July 20, 1969, the first spacecraft carrying astronauts from the earth actually landed on the moon! People were able to watch as a person walked on the moon’s surface for the first time ever.It was on television!

The astronauts sent the pictures of the moon back to the earth. The astronauts brought moon rocks back to the earth. From the rocks, scientists have learned a lot about the moon. The rocks were evidence that scientists could study to find out how the moon might have been formed. Scientists think the moon might once have been part of the earth. They think a large object from space hit the earth millions of years ago. The dust and ashes from the earth went into space and formed the moon. People have learned a lot aboutthe moon since early times!

修改后：

 On a clear night, the moon shines brightly overhead. You might think that the moon gives off light, but it does not. Light from the sun reflects off the moon‘s surface. Sometimes the moon looks like a large ball in the sky. Other times it looks like a tiny sliver.

  Myths, or legends, were made up by early people to explain why the moon changes shape. The early people of Greenland which is an island in North America thought the sun goddess was chasing her brother, the moon god, across the sky. The moon god ran so much that he forgot to eat, so as days passed, he became thinner. Finally, the moon god had to stop and eat. He got bigger, and the chase began all over again. 

  Today people understand why the shape of the moon changes. The changes in the shape of the moon are caused by the way the moon moves in space. The moon moves in two ways. It rotates, or spins around like a top. It takes the moon about twenty-nine days to rotate once. It also travels in a path around the earth called an orbit. The different shapes of the moon are called phases. This is what the phases of the moon look like:full, waxing gibbous, half moon, waning, waxing. The phases of the moon in order are: full, waning gibbous, half moon, crescent, new moon, waxing crescent, half moon, waxing gibbous, and full.

  The moon takes about twenty-nine days to orbit around the earth. The sun always lights up half of the moon. We do not always see the lit-up half from the earth. When you see all the lit-up half of the moon, the moon appears to be a full circle. This is called the full moon. As the moon travels around the earth, we see less and less of the lit part. This is called the waning moon. Soon the lit-up part of the moon disappears from sight. This is called the new moon. Then the moon starts to look lit up again, and the lit part that you see gets bigger each day. This is called the waxing moon. It takes about twenty-nine days for all the phases. That’s the same amount of time it takes for the moon to make one trip around the earth.

  Starting in the 1950s, spacecraft were sent to study the moon. The spacecraft orbited the moon. In this way, scientists learned more and more about the moon. Then, on July 20, 1969, the first spacecraft carrying astronauts from the earth actually landed on the moon! People were able to watch as a person walked on the moon’s surface for the first time ever. It was on television!

  The astronauts sent the pictures of the moon back to the earth. The astronauts brought moon rocks back to the earth. From the rocks, scientists have learned a lot about the moon. The rocks were evidence that scientists could study to find out how the moon might have been formed. Scientists think the moon might once have been part of the earth. They think a large object from space hit the earth millions of years ago. The dust and ashes from the earth went into space and formed the moon. People have learned a lot aboutthe moon since early times!

    初一:程锦升