UFO's Throughout History?

Several pieces of artwork throughout history in which many believe is evidence of being visited by intelligent life forms other then our own. The art in its various forms has also come with highly argued legends and/or ancient literature written about them. For instance the Sanskrit text from the 10th century displayed below called the "Prajnaparamita Sutra", depicts two objects called "Vimanas". The Ramayana describe the Vimanas as double decked, cylindrical aircraft with portholes and a dome. "It flew with the speed of the wind and gave forth a melodious sound".