How would ancient natives who lived in caves know what a helmeted space suit or a jet airplane look like?

Cave drawings from all around the globe depict space suited beings in helmets with antennae ( to communicate with the UFO ???), and unidentified flying objects. Some that look like the UFOS that have been seen and reported around the globe recently, the Mayan Indians had a gold trinket that looked like a jet aircraft it was tested for aerodynamics and was found to be aerodynamically sound. So do you think they had a vision from god or did aliens land here during the stone age!