Even though everything might look still, all of the planets and stars in the Universe are moving. They are moving relative to each other, but they are also rotating, like a spinning top. On Earth, we get night and day because the Earth is spinning about an axis. The moon is orbiting the Earth, so we see it in different phases, and the Earth and Moon are orbiting the Sun, giving us a year. That means, even when you are fast asleep at night, you're really moving at thousands of miles an hour! Crazy, isn't it!?