The barren and silent moon

Science has told us so much about the moon that it is fairly easy to imagine what it would be like out there.

It is certainly not a friendly place. As there is no air or water， there can be no life of any kind. For mile after mile there are only flat plains of dust with mountains around them. Above， the sun and stars shine in a black sky. If you step out of the mountain shadows， it will mean moving from severe cold into great heat. These extreme temperatures continually break rocks away from the surface of the mountains.

The moon is also a very silent place， for sound waves can only travel through air. But over the broken horizon， you see friendly sight. Our earth is shining more lightly than the stars. From this distance it looks like a huge ball， colored blue， green and brown.