The truth is we don’t know if aliens visited our planet before, because we know very little about the eons of time Earth existed before us. Source: Luke Hancock / Public Domain.

Ancient Aliens: Loads of Time, Zero Evidence

Allthathistory October 8, 2024

The idea of being visited by aliens is an appealing one, and it is not hard to see why. It would allow those who believe to feel that they are part of something much bigger, that there is a wider universe out there waiting, one which renders trivial all our domestic problems, from a planet on fire down to rising grocery prices.

Of course, “believe” is doing a lot of heavy lifting here, and much of this kind of theorizing comes from the “wouldn’t it be cool if” school of speculation. If we have ever been visited by aliens (and the respectable scientific community is unanimous that we have not) then they would have to be very strange aliens indeed to fit all the criteria.

They would have had to crack interstellar travel, for one, using technology which defies not only our own inventive brilliance but everything we know about the universe. They would need to have access to a host of exotic materials not available anywhere on Earth, nor anywhere we have seen in the universe either.

Alternatively these aliens would have had to commit so strongly to their mission to Earth that they would have kissed goodbye to their home planet forever, either through the use of generational ships or time dilation from the speed of their travel causing centuries to pass back home while they were gone. Whichever way you spin it, it would be very, very challenging to visit us.

And all this just to look but not touch? Why are these aliens, who can travel the stars, so discreet upon arrival that they leave zero incontrovertible evidence, and are only seen by a handful of people, almost always from the US?

Maybe aliens exist in our own solar system, an intriguing thought which remains perhaps the best hope for us encountering extraterrestrial life. But we have scoured our backyard and found nothing that suggests intelligent life, or more accurately everything we have seen to date leads to the conclusion that our neighbors are dead planets. If there’s life, Jim, it’s not as we know it.

But there are other arguments for aliens and weirdly some of these are not so easily dismissed. There are many caveats, to be sure, but it is indeed entirely possible that we have been visited in the past by an interstellar interloper.

And these aliens would be ancient indeed.

A Light Touch and Gone Forever

For a start, these could not be the “aliens” that fringe theorists routinely cite when trying to pe up some obscure piece of archaeology. All of the weird humanoid depictions on cave walls, all of the strange descriptions of apparent “future tech” from ancient texts, none of these can be aliens for one simple reason: they are all too recent.

The Ark of the Covenant is often cited as an example of future tech, but if this came from ancient aliens they would have left traces of their presence and none, not even the Ark, can be found (J James Tissot / *Public Domain*)

These aliens would have visited within recorded history, and the traces of their presence would not be so limited. We would have to go back a lot, lot further than that to find a time when aliens could have visited.

For nothing, after all, is permanent (or almost nothing, but we will come to that). It is important to look at the timescales available, and what we know about life on Earth.

For a start, humanity has only existed for a very small amount of time compared to the age of the Earth. We have only had complex cultures for less than 10,000 years, and before that the hunter gathering societies which spread across the world did so in the last 300,000 years.

The odds of alien interaction at any point along our personal journey as a species is effectively zero on a cosmic timescale. The coincidence of aliens arriving just as we were able to perceive them is, literally, astronomically unlikely.

But the Earth itself is not so young. There are eons of time before we claimed this planet of our own: 4.5 billion years of it, and 3.7 billion as a life-supporting planet.

300,000 years is a fleeting moment next to such timescales. There are billions and billions of years during which aliens could have visited, stayed, flourished and died during these unobserved timescales, making use of our planet long before humanity ever existed.

Surely there would be evidence of these ancient aliens? Well, there is the crux of the matter: it is entirely possible that there would not be.

The surface of the Earth is in a constant state of reinvention. There is nothing on the planet’s surface that is older than 2 million years, and although the crust does contain fossils, evidence of life which is far older, these are extremely few and far between. As far as life goes, the geological record of our planet is almost completely silent.

There is no reason that aliens could have visited during these timescales. Nothing of their culture would survive as evidence for us today, just as nothing of us will survive two million years from now. All of our achievements will be gone, turned to dust.

Except that is not entirely true. We have, in the last few centuries, left scars on our planet which may act as telltale clues for whatever life replaces us in the future. Our metal deposits have been extensively mined, and from the perspective of the far future are geological makeup would look unexpected as a result.

We have left scars on our planet that even geological time cannot erase (WClarke / CC BY-SA 4.0) — *We have left scars on our planet that even geological time cannot erase (WClarke /* *CC BY-SA 4.0*)

Similarly we have tunneled and exhausted a large part of our oil and gas reserves, and altered the nitrogen balance in our soils through industrialized agriculture. These will leave indelible marks which, potentially, could be seen for millions of years and recognized as clues to our existence.

We have not seen any such evidence from the distant past ourselves. If aliens have been here before, they didn’t come for our planet’s reserves, and everything seems to be where it should be. The Earth was apparently virgin territory for us to exploit.

So, the only space for aliens to have visited is at a time so distant that all traces are now gone. They had time, to be sure, but they are unreachable to our science.

Such aliens might as well have not existed at all.

Header Image: The truth is we don’t know if aliens visited our planet before, because we know very little about the eons of time Earth existed before us. Source: Luke Hancock / Public Domain.