evidence: One famous piece of evidence is a photograph of an "astronaut" carved into a 16th-century Spanish cathedral in Salamanca. This cathedral, known as Catedral Nueva, has a strangely modern figure of what looks like a helmet-wearing astronaut on the façade of the entrance. [...] That is what Erich von Daniken posited in 1968 with his book Chariots of the Gods. This book championed the concept of the ancient astronaut theory and quickly became a best-seller, bringing the idea of art depicting extraterrestrials into the public consciousness. With the picture of the astronaut on an old cathedral, it might be tempting to believe that Erich von Daniken and the wild-haired guy were right all along.