Exploring the Moon

The Moon: Gateway to the Solar System

Digging Up Old Secrets

Astronauts went to the Moon.
They dug into the ground.
They were not just digging dirt.
They were digging up old secrets!

The rocks they found are special.
The rocks tell us how Earth started.
They tell us how the Moon started too.

The rocks show us something else.
Long ago, space rocks hit the Moon.
This happened a lot.
The rocks can tell us when.

We cannot learn this from Earth rocks.
Earth changes too much.
Mountains grow on Earth.
Volcanoes erupt on Earth.
Wind and rain wear rocks down.
This erases old clues.

But the Moon does not change much.
So Moon rocks keep their secrets.

Looking at the Moon

The Moon has two sides.
We can see one side from Earth.
Scientists took pictures of the other side too.

The Moon has two kinds of land.

The first kind is called highlands.
Highlands are light-colored.
Highlands have many craters.

The second kind is called maria.
Maria are dark and smooth.
Maria formed from melted rock called lava.
The lava filled in low spots long ago.

Here is a puzzle for scientists.
The far side has fewer maria.
The near side has more maria.
Why is this true?
Nobody knows for sure yet.

The far side has many craters.
Craters are holes made by space rocks.
The craters tell a story.
Long ago, many space rocks hit the Moon.
This may have happened to Earth too.