Why Would Ancient Astronauts Visit Earth?

By NASA ([1]) [Public domain], via Wikimedia Commons

By NASA ([1]) [Public domain], via Wikimedia Commons

I continue my contemplation of the kind of evidence that would convince me of the truth of the ancient astronaut hypothesis. This week I consider the question: why did the come?

Last week I began to explore the question: If there really were ancient astronauts, what kind of evidence would we find? (see http://dynamiclethargyfilms.ca/if-there-really-were-ancient-astronauts-what-kind-of-evidence-would-we-find/). I started on a new project this week; it is more of a writing exercise than something plan to share, but that depends on how it turns out. I did some more thinking about the ancient astronaut hypothesis and pushed a little further ahead with my exploration.

Why did they come?

I think that the  reason ancient astronauts would visit Earth would have an effect on the kind of evidence that we would find. I came up with four possible explanations. There could be others that I didn’t think of, so I am open to suggestions.

Resource extraction

Could they have come to obtain resources? This idea was explored in the movie Avatar http://en.wikipedia.org/wiki/Avatar_(2009_film) from the perspective of the alien visitors. Of course it does place us humans in the role of the aliens.

I think that this is unlikely. Materials of all kinds are spread throughout the Universe. With the vast distances and resulting cost of transportation, it is hard to imagine anything that would be valuable enough to extract and ship to other solar systems.

For example, it appears that vast quantities of hydrocarbons exist on other bodies in our own solar system. It is believed that the volume of hydrocarbons on Saturn’s moon Titan far exceed what exists on Earth. See http://en.wikipedia.org/wiki/Lakes_of_Titan. It is far beyond our ability to extract this resource and bring it back to Earth now. By the time we develop the kind of technology that might make it worth while, it is likely that the technology would make hydrocarbon unnecessary.

Nevertheless, let us assume that this was the reason for the aliens to visit. What kind of evidence would we find?

One type of evidence would be the remains of resource extraction, such as abandoned mines and waste heaps. The extraction would need to be on a very large scale, and so should be very obvious.

Another type of evidence would be the rarity of resources that should be abundant. If significant resource extraction had occurred, then those resources would be dramatically depleted. This might not be immediately obvious. We usually assume that the way things are when we find them is the norm. Only later research would unveil unexpected rarity.

I am not aware of any evidence along these lines.


Could they have come to colonize? Many of our own science fiction stories postulate humans setting up colonies on other planets. Ray Bradbury’s The Martian Chronicles is an example of this. http://en.wikipedia.org/wiki/The_Martian_Chronicles

The experiences of the natives of the Americas and Australia under European colonization does not paint an optimistic picture of what humans could expect from alien colonizers. The best evidence for alien colonization is that humans would at best be a marginalized minority and at worst we would be extinct. Neither of these seem to be the case.

It is, of course, possible that an alien attempt at colonization failed, which would let humans survive. If that were the case, then the evidence that we might find would be the remnants of  alien technology.

Since the aliens would need a technology far beyond what we have now, any remnants could well be beyond our ability to recognize. In any event it would be beyond our current abilities to create.

Although there have been claims of advanced technologies found in ancient cultures, I have not heard of claims of technology that is beyond our current capabilities. The evidence would probably not be some isolated technology, but would involve a wide range of technologies. The evidence would not be ambiguous.

Scientific research

An example of how scientific study by aliens might go can be seen in the television docufiction program Alien Planet. http://en.wikipedia.org/wiki/Alien_Planet

In this scenario, the aliens would only be interested in the study of Earth, and would likely limit contact. This would mean there would be limited evidence of visitation. The primary evidence would be alien probes or their remains. While probes do land on Darwin IV in Alien Planet, and come to tragic ends, I think a scenario like that of 2001: A Space Odyssey is more probable. See: http://en.wikipedia.org/wiki/2001:_A_Space_Odyssey

There has been some serious interest in the search for alien artefacts on Earth,  and other planets and objects in the Solar System. So far as I am aware, there has been no credible claims of discoveries.

I found one scientific paper on-line that discussed the issue, but can’t find it now. The paper concluded that the solar system had not been imaged in sufficient  detail yet to preclude the existence of alien probes.

Crash landing/ cast-a-ways

Could have the alien visit to Earth be unintentional? In this scenario, the alien visitors would have been forced to land on Earth and be unable to leave. The closest example in science fiction I could think of was the original Planet of the Apes movie. See:


It is in this case that some of the claims of ancient astronaut believers might be true. Trapped on our planet, and bereft of their advanced technology, ancient astronauts may very well have resorted to helping the native human population to develop more advanced technology.

The plot of Planet of the Apes does not follow this direction though. The astronauts are barely able to survive, much less become like gods to the indigenous beings. Edgar Rice Burroughs’ John Carter stories have a more optimistic, albeit unrealistic, outcome. http://en.wikipedia.org/wiki/John_Carter_of_Mars

Unambiguous evidence of this scenario would be difficult to find. If there was a crash, there would be no direct evidence beyond the immediate site of the crash, which could be quite small in extent. Any other evidence would be more easily attributed to more prosaic explanations.

So where do we stand now?

I have identified some lines of evidence that might provide proof of alien visitation. By no means do I feel that I have covered the whole range of possibilities. There are still questions I raised in my previous blog post that I would like to address.

I haven’t actively looked for any of the evidence that could provide proof of alien visitation. Indeed, much of the search is beyond my ability and resources. For now I will limit myself to consideration of the possibilities.

Some of this speculation could be the basis for some interesting science fiction tales.

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