On the moon
People have visited the moon and walked on it, so we know what the
surface of the moon is like. This big ball of gray rock has broad, flat
plains covered with powdery rock dust. There are rugged mountains. And
there are thousands of billions of round pits called craters.
The craters were made by chunks of rock that smashed into the moon like
bullets. Such chunks of rock, called meteoroids, move around the sun,
just as the earth and moon do. During the billions of years since the
moon was formed, billions of meteoroids have bumped into it. The moon
and the meteoroids were moving so fast when they crashed together, that
the meteoroids dug craters in the moon’s surface. Now, the moon is
pitted and pocked with these craters.
Some of the craters are no bigger than pinheads, some are the size of a
car tire, some are hundreds of feet (meters) wide. But most are about
five to ten miles (8 to 16 kilometers) wide. The biggest is about seven
hundred miles (1,100 kilometers) wide. When the meteoroids struck, they
usually threw up walls of rock around the craters they made. The moon’s
mountains are really the walls of huge craters.
There is no air on the moon to scatter the sunlight, so even in daytime
the sky is pitch black and filled with stars. Because the moon turns so
slowly, one day on the moon is as long as fourteen days and nights on
earth. During the moon’s daylight hours, the rocky surface grows so hot
it would burn you if you touched
This is the part of the moon where American astronauts landed in 1972.
In the background are part of the Taurus Mountains.
it. But during the long night, the moon grows colder than the coldest
place on earth.
The moon’s gravity isn’t as strong as earth’s gravity. On the moon, you
could jump six times higher than you could on earth, and lift things
that would be too heavy for you to lift on earth.
With no air, there is no sound on the moon. And there is no wind to stir
the rock dust that lies thickly on the plains. The moon is a still,
silent, barren, lifeless place, unlike any part of earth.
