I contacted the assistant professor of my local university that I attend about Ancient Astronaut Theory, due to the fact that I am very interested in the subject. For the record, the man has a PhD and M. Litt in Ancient History from University of St. Andrews in Fife, Scotland. Here is the e-mail he sent back to me.

You're correct in that I'm the Ancient Historian; however, I cannot claim
any expertise in the area of AAT. I ran a search for you through the online
database of L'Annee Philologique for serious scholarly articles on the
subject and, frankly, there were no results, meaning that since at least
1967 there has been nothing that's generally accepted as even possible
that's been written by the scholars of the Classical World, at least where
Greece and Rome are concerned.

This is primarily due to a number of factors - one of which is that most of
the alleged contact between man and extraterrestrials is claimed to have
taken place prior to the advent of classical societies and, indeed, writing.
Hence evidence such as cave paintings is bent to the purpose of 'proving'
contact, such as with the Val Camonica cave in Italy (the one which has
people with bubble-heads, presumably some manner of spacesuit).
Alternately, 'researchers' have gone and pestered peoples such as the Dogon
of Mali so as to gain access to their 'secret knowledge' of prior contact.

Ergo, for a reading list, all I can send you to is the usual list of
crackpots that you've probably bumped into already. Erich von Daniken's
'Chariot of the Gods', for example, is usually taken as the seminal work in
the field, or you might check out Robert Temple's 'The Sirius Mystery' -
which, I might add, I've always thought to be rather creepy in a 'how could
they possibly know?' sort of way (he's the one that pestered the
tribespeople). Naturally, both of these authors have something akin to zero
credibility in terms of the academic world.

Good luck with your enquiries/don't join a spaceship cult,

wow what a nice guy, he should post on ATS.

I don't really like AAT because it seems a long winded answer to a simple question, panspermia or exogenisis i can accept as possible and i suppose aliens could have visited millions of years ago, if they did i bet they avoided the savage monkey people and just enjoyed a bit of shore leave.

Maybe with the increase in satalites and probes in space we'll see a ship wizz through our solar system or maybe we'll notice them watching us from the dark side of the moon - i just don't see why they would give wild tribes information mathmatics information? The mayan calander only works for this solar system and this planet, hardly the sort of system an alien life form would use -why don't they use something more universal like the startreck star date or some galatic decay constant, bing bang ripple timer or some such¿

If i was an alien i would know how far the light from the big bang has gone so far, due to the fact everything else in existence is behind it i would know its rate of travel as the vacume would be perfect so i could work out the current time in the universe by its size, the time would be 1trillion trillion miles oclock or some such.

So if you find a tribe who use a non-earth based system for counting or viewing the universe i would accept that maybe they know aliens.

meh, they never even know about atoms electrons, etc yet alone string theory or whatever really makes the world corporal - aliens could have told them something useful like unified field theory

this is how i picture the conversation going,
et: take us to your leader.
em: er, we're sort of still a prehistoric society and really we weren't planning on installing a proper leader until long after the start of the iron age -how about a wise woman?
eth. well, we bring you a message of peace.
emh er good, would you like a bit of stone? -you can make a spark with it!
et: oh thanks, we can offer you great things - a system for measuring the time which has passed.
em: thanks but we got that covered.
et: how about rough maps of the world and observations of the near planets? em:-thank's but no we're good for that too,
et: we could build you some rudamentary piles of cut stones to put dead people in if you want?
em: yeah er, we're basically in the bronze age now so we've been cutting large rocks for thousands of years but yeah that would be great.

To me, the idea of ancient cosmic visitors to our planet isn't far fetched at all. Not in the least. It's something we have such little grasp on that it's just as likely that aliens were here several million years ago as it is they were here seventy thousand years ago, because we have no clue how advanced other alien civilizations could be. We don't even know if they exist!

But it would probably take care of the problem of the missing link to consider the possibility that aliens tested with advanced primates to make them smarter, and hundreds of thousands of years later we call ourselves human.

It might also answer some questions about God and religion. i.e. the source. God = Law in ancient times and it would have been (still is) the perfect way to reign in the masses and control them not so much for ominous reasons, but also for organizational purposes. That still works today!

It's not entirely out of this world (no pun intended) to consider that alien intervention may have been the leading cause of a great many achievements throughout human history.

All I need is some evidence! Sadly, just because it's believable doesn't mean it happened, and we'll likely never know for sure. Time has a way of wiping every trace of evidence away. In 100,000 years there won't be a trace of humanity left on this planet. 100,000 years later, i'm sure there is zero evidence that has survived.