Because the bright light of the sun hides their light.
Are there stars in every direction around the earth?
There are stars in every direction around the earth.
How do we know this?
Because stars may be seen from every part of the earth, when it is night.
Stars are in every direction around the earth, just as we may imagine the apples to be in every direction around a boy who has climbed into a tree full of that fruit.
What planet moves around the earth?
The moon moves around the earth.
Upon what part of the moon does the sun shine?
It shines upon the part towards the sun.