Actually when i saw that I thought this
The angle is a bit off but from the cockpit of another plane the profile look of a Cessna looks just like the one in the hieroglyph.
But that doesn't mean the guy who did the drawing saw a Cessna. Surely you've seen some really weird or cool looking clouds? I've seen ones that I thought looked like dragon, space shuttles, cars and some shapes that were just had interesting geometry. If I'd had a camera I would have taken a picture of them.
The simplest answer to me is that some guy back then saw some cool shapes in the ski (just as I have) and decided to record except they used stone rather than a digital camera. Extrapolating out visitations from Aliens from these pictures is just way to many inductive steps for my liking. To paraphrase Occam's razor: "don't add any more complexity to an observation than is necessary because you'll likely be wrong".
I saw you posted a few questions earlier so here's a crack at an answer:
Do Aliens exist?
Almost certainly. In Classical and Relativistic physics its reasonable to think the edge of space is defined by the distance light has travelled since the big bang. As a result the universe is finite. This isn't compatible with Quantum Mechanics. One of the quirks of quantum mechanics is that there is no such thing as a true vacuum (i.e. totally empty space).
Quantum theory predicts that particles and antiparticles, with equal but opposite properties and speed, can and do spontaneously appear out of nothing. The particles that appear then annihilate each other almost immediately. This process gives rise to what is sometimes called 'Quantum Foam' As they have equal but opposite properties there is no change in Enthalpy or Energy and the Laws of Thermodynamics are conserved. The result of this is that there is no such thing as 'nothing'. Tis means that anything and everything has something in it and that Space is infinite, even beyond where light has got too since the Big Bang.
We know that the probability of a universe forming is greater than zero (if the probability was zero then our universe wouldn't exist and neither would we). No matter how small the probability of an event occurring it will definitely occur in an infinite space. It will also happen an infinite number of times creating an infinite number of Universes.
We also know that the probability of life occurring in a Universe is greater than zero by our very existence ergo if we have a finite probability acting on an infinite space then we have a certainty that life must occur somewhere else.
This argument is based on the assumption that Quantum theory is roughly on the right track and not completely wrong. However, by its very definition science can never provide a 100% proof (anyone who says otherwise doesn't know what they are talking about). But we can be pretty damn confident that we're reasonably close. If we weren't then these computers wouldn't work as anything with a chip in it works on the basis of Quantum Mechanics. In particular, experiments were done to see if quantum foam or something like it exists and it does. Quantum theory predicts that there is an attraction that will occur between two uncharged metallic plates in a vacuum (this would not happen in classical physics) so this was tested and the force that was predicted does occur by Quantum Mechanics does occur. This phenomenon is called the Casimir effect. On this and other evidence it seems highly likely that quantum foam exists. In order to really be certain we need to wait for the LHC at CERN to get going. If they find something called the Higg;s boson then quantum foam and therefore aliens, are pretty much a certainty to exist.
NB Although I have a high degree of confidence in the existence of alines life I'm not expecting a visit, nor can i think of any good reason why they'd look like the things seen in Sci-FI movies.
