Astronomy is the study of space; stars, planets and comets. The science of astronomy has been practiced since prehistoric times. Before the invention of telescopes, ancient astronomers studied the movement of stars in order to tell time and decide when to plant or harvest crops.
Astronomy was also important in helping sailors and travellers find their way when there weren’t reference points like mountains, coasts, or other landmarks.
Famous astronomers include Nicolaus Copernicus, who developed the theory of a sun-centered universe, and Galileo Galilei, who discovered the moons of Jupiter.