How much of the moon can you see? Most people would say fifty percent, but they’d be wrong. You can’t see more than fifty percent at a time, but look upward for a year, and you can see nearly sixty percent of the moon’s surface. We’ll tell you how.

Look up in the sky on a night of a full moon and you might think you’re seeing all the moon you can. But before the night is even up, you'll see more. Although someone on Earth can only see half the moon at a single time, and the sun can only illuminate half the moon at a time, put in enough time and the motion of the moon lets us see the universe's extended cut. The motions that let us see more are called the librations of the moon.

The first libration comes from the fact that the moon is tilted with respect to the sun’s light. If the poles of the moon were exactly where light and darkness met as the moon went around the sun, we’d lose out on a considerable amount of data. But because the moon is tilted so its north pole is slightly away from the sun during one part of its orbit, and slightly towards it two weeks later, we can see the north pole of the moon lit up in one part of the month, and the other in half a month. This is called the lunar libration.

There’s also the daily libration. The Earth is a big place with respect to the size of the moon, and when it spins it covers a lot of ground. Moonrise is seen from one side of the planet and moonset is seen from the other. Stand in the right place and you’re seeing the moon from two opposite edges in a single day. This lets you see little slivers of extra moon on each side.