There is the daily rotation of the celestial sphere, the monthly cycle of the moon, the yearly cycle of the sun, and the varying cycles of wandering stars, the planets. The earliest Greek astronomers were occupied with seeking explanations for these patterns, and modern astronomy was born when Newton showed that they could be understood based on his universal law of gravitation. With the rise of science and technology came the telescope and an entirely new window on the universe. Stars were seen to clump into galaxies, and galaxies would cluster into huge swarms of galaxies. Today we know the universe to be an incredibly complicated place with scales in time and space that dwarf our imagination.
Astronomy is an observational science.
We can't go to other stars or galaxies and tinker with them as we choose. We must sit passively and watch events unfold. Therefore, astronomy may seem much like a collection of facts without structure, but there are methods to the madness. We must keep alert for the underlying ideas that simplify and connect. It is a strange and wonderful world out in space.