1 Martian 1: These alien programs on Earthling TV are laughable!
2 Martian 1: As if we would have visited Earth hundreds of years ago, pretended to be gods, and built pyramids for them!
3 Martian 2: Actually, ancient pyramids would be a good place to hide our invasion machines. Imagine if they were there all along, just waiting for us to arrive.
4 Martian 1: To the time machine!!

Looking at ancient rock paintings or rock carvings and saying that the fact that some of them look a bit like aliens or flying machines implies that there were actual aliens around, is a bit like looking at human culture for the last few decades and concluding that lions can speak English.

The image in the second panel is part of the lid of the sarcophagus of the Mayan ruler K'inich Janaab' Pakal. It's a beautiful piece of classical Mayan art, and notorious for often being interpreted as representing a guy in a spaceship by "ancient astronaut" pseudo-historians.