Have Aliens Walked Among Us?

Aliens on Earth?
Many stories get told about aliens visiting Earth. No proof this exists, but the idea is a popular one.

Getty Images 

Have aliens ever visited Earth? It's an interesting question that assumes there are aliens and that they actually want to visit our planet. There are people who think visitors from outer space have been here, and some even insist that they've visited with them (or even mated with them!). The informal pulp magazine "literature" we often see at the grocery store checkout line abounds with alien baby stories, but so far there's no proof that anyone has visited Earth from another planet. Still, it does raise the question: Is it even possible for a physical being to travel here and walk around unnoticed? 

How Would Aliens Get to Earth?

Before we can even address whether beings from another world have come to Earth, it's useful to think about how they could get here in the first place. Since no other forms have life have been detected extraterrestrial life in our own solar system, yet, it's safe to assume that aliens would have to travel from a distant solar system. If they could travel at close to the speed of light, it would take decades to make the trip from a close neighbor such as the Alpha Centauri system (which is 4.2 light-years away). 

Or would it? Is there a way to travel the incredible distances of the galaxy faster than the speed of light? Well, yes and no. There are several theories about faster-than-light travel (explained in great detail here) that would allow for such trips to take place. But, if you look at the details, such travel becomes less of a possibility.

So is it impossible? Right now, yes. At the very least interstellar travel will involve science and technology that we have yet to even dream about, let alone develop.

Is There Evidence That We Have Been Visited?

Let's assume for a moment that it is somehow possible to traverse the galaxy in a reasonable amount of time. After all, an alien race able to visit us would be more advanced (at least technologically) and able to build the ships needed to get here. So, let's say they have. What evidence do we have that they've been here?

Unfortunately, nearly all of the evidence is anecdotal. That is, it is hearsay and not scientifically verified. There are many pictures of UFOs, but they're very grainy and lack the crisp details that would stand up to scientific scrutiny. Most of the time, since the images are usually taken at night, the photos and videos are nothing more than lights moving in the night sky. But, does the lack of clarity in the images and videos mean that they are fake (or at the very least useless)? Not exactly. Photographs and video may shed light on phenomena that we can't explain right away. That doesn't make the objects in those images proof of aliens. It just means that the objects were unidentified. 

What about physical evidence? Is there any legitimate material proof that exists? There have been claimed discoveries of UFO crash sites and interactions with actual aliens (dead and alive). However, the evidence is still inconclusive at best. Most of the physical evidence lacks corroboration or any witness at all. Some things can't be explained, but that does not necessarily mean that they are alien.

Could aliens arrive in ships like this?
The most popular view of alien spacecraft is of disk-like flying saucers arriving in Earth's skies for a visit. Lorenz and Avalar, Getty Images.  

However, it is interesting to note the evolution of the evidence over the years. Specifically, in the early 20th century, nearly all stories of alien spacecraft described seeing something resembling a flying saucer. Any alien beings were described as looking similar to humans. In more recent years, aliens have taken on a more alien appearance. Their spacecraft (as reported by witnesses) look far more advanced. As our own technology advanced, the design and technology of UFOs increased proportionally.

Psychology and Aliens

Are aliens figments of our imagination? This is a possibility we can't ignore, although true believers will not like it. Simply put, the description of aliens and their spacecraft are correlated with our biases and beliefs of what we think they should look like. As a consequence, in our imaginations and our science fiction movies and stories, they almost always look like bipedal humanoids. However, chances are pretty good that any aliens "out there" may not look at ALL like us. So, that's something to consider.

Will aliens look like humans? Probably not.  Tara Moore/Getty Images

As our understanding of science and technology evolve, so does the evidence. The simplest explanation for this is that our societal and environmental influences are causing us to see things as we want to see them; they fit our expectations. Had we actually been visited by aliens our perception and description of them shouldn't have changed as our society and technology did. Unless of course the aliens themselves have changed and had dramatic increases in technology over time. This seems rather unlikely. 

Any discussion about aliens comes down to the fact that there is NO conclusive proof that we have been visited by alien beings. Until such evidence is presented and verified, the idea of alien visitors remains an enticing but unproven idea.