One such piece was discovered in Nepal, a medallion known as the Lolladoff Plate depicts a curious representation of a man like figure combined with other animals and the sun. There have also been sightings of UFO's in medieval and Renaissance art which depict scenes from the Bible. However, there's no way of knowing whether these figures were symbolic or representational in nature.
With the creation of science fiction, depictions of spaceships and UFO's skyrocketed, several of which are now instantly recognizable in modern cultures around the world, such as Star Trek's Enterprise and the Star Wars Death Star. More conventional spaceships have also been explored in the world of pop art, where artists like Andy Warhol created several different works featuring them.
Children are brought up with a fascination for space travel and it's not uncommon for a child's room to be decorated in pictures of aliens, UFO's, and spaceships at least once in their life. However, as more adults turn their attention to the cosmos, artists have developed artwork that is specifically tailored for older audiences.
Additionally, photographs from Earth's space travels have become increasingly popular and detail events such as the moon landing as well as pictures taken from spacecraft and images of individual ships.