This is a close up photo I took of the surface of the moon.
One reason there are so many craters on the moon is because the moon doesn't have an atmosphere. Meteoroids don't burn up as they approach the moon (they all hit).
Another reason is that they don't just disappear over time--there's no wind or rain to erode the craters (like there is on Earth).
Many of the craters we see on the moon today are from collisions that occurred billions of years ago, when the rest of the solar system was still being formed. These impacts are perfectly preserved on the lunar surface.
One more note: I don't want to admit how old I was when I learned that the moon isn't emitting light, but instead, reflecting it. The darker areas in the photo are plains of solidified lava, which reflect less sunlight than other areas.
