Transcript: Ten Ways We May Have Already Detected Alien Life

In celebration of both this channel's one year anniversary and reaching three thousand subscribers, this is a full length documentary made in thanks to the fans of this channel for your support. I am having more fun creating my videos than a person should be allowed to have and the channel has become something that I really love and get excited about.

I never expected it would grow like this when I made my first video nearly one year ago, and it's all thanks to you folks for making it possible. Do look forward to many more years of videos which I will continue to make whenever I come across something cool and unusual in the world of science. So here are ten ways we may have already detected alien life in the universe.

Since the advent of space science, the human race have asked ourselves "are we alone?". In the past, answering this question seemed more straightforward than it is today with Percival Lowell's canals on Mars and pulsars being the signals from little green men. But none of that panned out and the fact is, we still don't know the answer to the biggest question in the universe. But we do know that life itself, at least microbial, seems fairly straightforward, resilient and easily arisen and may have done so on multiple bodies in our solar system alone. It seems likely that we are on the cusp of answering the question, at least far as simple life is concerned.

But what of other civilizations? This too seems to be increasingly moving into the territory of getting answered. If NASA researchers are to be believed, it could happen at any time and probably will within the next 20 years. But, in this search, we must be careful and cautious to prove that whatever we find does indeed indicate the existence of extraterrestrial life. That has not been easy so far.

It's worth noting that in the search for extraterrestrial life there have been many false starts, so it pays to take this entire list with a grain of salt. Two examples of this are HD 164595, a sun-like star with a known planet that appeared to be the origin of a radio signal and it became a major SETI target at the time. But the signal didn't repeat which is SETI's chief criteria, and it turns out, that the signal was within a military communications band. In other words, the origin was very likely a human-launched spy satellite whispering secrets from orbit.

Another example would be the near-earth asteroid 1991 VG. It's a highly unusual asteroid that has a really odd orbit that's a bit hard to explain. It's very similar to Earth's orbit, and that means earth should have long ago flung it out into space or smacked into it. It also has really strange, almost artificial looking reflectivity that makes it change brightness as it rotates to the point that one theory for its origin was that it was a spent rocket stage that someone had forgotten about.

But one other possibility that was floated at the time was that it was an object of alien origin known as a Bracewell or Von Neumann probe, more on those later. But over the years further research has revealed that it's just a strange rock and the alien origin possibility for it is now dead.

This list starts with the least likely candidates and ends with the most likely to have been something of alien origin. I included all life in the criteria, because even a single microbe answers the question. That is not to say that any of the cases will yield the answer to the 'are we alone?' question since some of the options are unlikely to repeat and thus probably won't be available for further study and will remain mysteries forever.

There are also some notable omissions for possible life, for example Europa where we currently have no indication that there could be life there, but the conditions are such that it would be unsurprising if such evidence were found in the near future. Those omissions are for a future dedicated list.

10. Tesla's Signals

This case suffers from being obscured by the mists of time and also a mistaken viewpoint of the period that Mars was almost certainly inhabited by an alien civilization. It clearly is not, the only alien civilization with a presence there is us. There is also a ton of misinformation out there on the internet regarding the originator of this possibility, and many, many urban legends have been spawned from material surrounding Nikola Tesla.

But the underlying claim does technically remain unexplained, though as I understand it and this comes from very old information I heard long ago, it would be extremely difficult to verify today because the frequencies at which it was supposedly visible are so saturated by earth interference that you'd have to put a receiver on the far side of the moon to block everything and check them out.

Nikola Tesla on several occasions claimed that he had received unambiguous alien radio signals from space. But he never gave much in the way of details that we could investigate today. He typically associated them with Mars, which at the time was subject to claims from several mistaken observers to have canals on it. It does not, and as far as radio goes Mars is about as uninteresting of an object as you can get.

Now, I don't doubt that Tesla did in fact receive strange radio signals during his experiments, but those were the very earliest days of radio astronomy done in a time when we had no idea what could emit radio waves. It turned out many things do, including objects in our own Solar System. You can literally grab an old short wave radio and make a loop antenna and listen to Jupiter make repeating ocean-like whooshing sounds that if you didn't know were natural, could be mistaken for something else.

As a result, I think this is a case of smoke without a fire. But since it technically remains unexplained, I put it on the list. Who knows what Mr. Tesla heard.

9. Long Delayed Echoes and Von Neumann Probes

This gets into unexplained radio phenomena that are almost certainly natural in origin. But since we haven't pinned down exactly what causes them, there remains a rather spooky possible alien origin though it is so far beyond unlikely and so highly speculative that I'm barely comfortable including it. But, since it's technically possible, on the list it goes.

In radio there is something called a Long Delayed Echo, or LDE. These occur when a broadcaster sends out a signal and then receives it back after a long period of time has elapsed, often tens of seconds. Now, there are lots of possible scientific explanations for these that included signals getting trapped into a loop going around the earth when the conditions are just right in the upper atmosphere, and signals can bounce off objects in space and return. While we don't yet know for sure, the explanation is most likely natural.

But, the universe is extremely old. Easily old enough for an advanced species in the galaxy to have developed. One possible way for such a species to explore the galaxy is to use self-replicating Von Neumann probes. These are probes that can make copies of themselves like viruses and spread out into the galaxy to explore it. The most famous example of this in science fiction would be Arthur C. Clarke's monoliths from 2001 - A Space odyssey.

With probes of this type, you could theoretically put a probe around every star in the galaxy. That would not take long, it could be done in as little as half a million years, but if your civilization is millions of years old then that's not really a big deal. And the expenditure of resources to do it would be very low, you'd only need to build a few initial probes and send them out to self-replicate. It's actually a scary doable way to explore a galaxy for a sufficiently advanced species, so much so that we're not that far from being able to start this process ourselves.

In fact, this method is seemingly so easy that one of the major arguments against it is that if Von Neumann probes exist, they should literally be everywhere and should have consumed most of the galaxy by now. So much so that any civilization that comes across one might see it as an existential threat and destroy it.

There are arguments for, against and neutral as to the existence of Von Neumann probes and their implications on the Fermi paradox. But it does open up the possibility of such a probe being stationed in our solar system awaiting the proper time to initiate contact and cultural exchange with us. One way such a probe might announce its existence is to repeat radio signals back to the civilization emitting them, sort of like the aliens from Carl Sagan's Contact sending back images of Hitler opening the 1936 Olympics as a sort of initial way to say hello.

Could that be the origin of at least some of the LDE's? It's highly unlikely, but possible. So on the list it goes.

8. Gamma Ray Bursts and Alcubierre Drives

This possibility makes use of a very contentious, hotly debated highly theoretical advanced technology called an Alcubierre warp drive. In a nut shell, the idea is that while matter sitting in normal space cannot travel faster than the speed of light, space itself is not subject to that rule.

So if you can split off and accelerate a piece of space, you can theoretically make it go as fast as you want. If you have a space craft generating a field of sorts to split that piece of space off and send it traveling, it would carry the spacecraft sitting within it along and voila, faster than light travel becomes possible and still remains consistent with relativity because the spacecraft isn't actually moving, the space it's sitting in is.

I will go on record and say that I do not think Alcubierre drives are possible. The subject is fraught with all manner of arguments against it being possible in practice, not the least of which would be truly titanic energy consumption to make it work. But it does have its advocates and the basic core concepts involved are fully scientific, so I include it on the list.

One effect of an Alcubierre drive is thought to be the generation of huge amounts of gamma rays. These should be detectable at long distances. And, we do, in fact, see all manner of strange gamma ray bursts in the universe that are not well understood. One possibility, be it a diminishingly tiny one, is that these bursts are being produced when aliens fire up their warp drives.

7. The Borra/Trottier Signals

In 2012, Ermanno Borra released a paper that suggested that you could detect within the spectra of stars the presence of pulsed laser emissions consistent with the activity of alien races. Along with E. Trottier, Borra then searched through the Sloan Sky Survey for the presence of these signatures.

At the end of last year, Borra and Trottier released a paper that reported that they had indeed identified these kinds of signals in the sky survery. But it wasn't just one or two stars emitting them, it was 234 different stars in the Milky Way. And, the stars that were emitting them were overwhelmingly sun-like, meaning that they had sufficient age and stability for them to have developed advanced alien civilizations.

But stars are strange things and emit all sorts of signals, so natural explanations are always favored. But, to date, no follow up papers have been published regarding this story so it's very much in flux still. But, at the time, scientists were careful to caution that on a scale of one in ten, with ten being the least likely, these signals were a ten. Only time and more study will tell.

6. Fast Radio Bursts

Fast Radio Bursts are a fairly recently discovered phenomenon. While it's overwhelmingly likely that these are of natural origin, one theory suggests that they may not be and are consistent with an alien civilization using a beam to push solar sails and the FRB's are the result of leakage from those beams.

What's noteworthy here is that FRB's do not seem to be consistent with something large, such as a star or galactic core. This is not yet settled, but it seems that they would be more consistent with something originating from a much smaller object, such as a planet.

If so, that would help bolster the solar sail theory.

But where it gets strange is that the solar sail theory makes note of an odd coincidence involving FRB's. If you take the theory from the position of energy and extrapolate what you would need to power the FRB beam, it comes out that you would need a planet about twice the size of earth to have enough room to collect solar energy to create the beam.

On the other hand, if you take the theory from the position of engineering and likewise extrapolate what you'd need to actually build the beam emitter, it ends up that the characteristics of FRB's would be consistent with a water-cooled structure that also happens to be the size of a planet about twice the size of earth.

I stress that FRBs are probably natural in origin, but it's also hard not to scratch your head when coincidences like that start popping up.

5. KIC 8462852

With this case, we enter a new level of possibility because it's the first case where the natural explanations so far advanced have all fallen short and the alien origin theory has still not been discounted.

KIC 8462852 or Boyajian's star is an enigma wrapped within an enigma. The Kepler spacecraft observed the star long term in 2011 and found that within the light curve of that star there were strange dips present as something passed by and blocked the star's light. This in itself would not be unusual, lots of young stars have disc of debris where planets are forming around them that produce light curves just like the one at Boyajian's star.

But the star's motion strongly suggests that this star is not young and should no longer have such a debris disc. That led to the possibility that two planets had crashed into each other in the system creating a new disc. Sounds fair enough. But there are two problems here. The odds that we would just happen to be looking when a very short term event like that happened are, well, astronomical. The second problem, and this discounted that theory, is that such discs absorb light from their star and radiate it back out in the infrared. No infrared radiation was detected at the star consistent with this. Whatever it is, if it's any kind of material, it has to be cold.

But, comets are very cold objects. So the next theory to come up was that a red dwarf, which is there, is passing by Boyajian's star and disrupted its oort cloud sending a hail of cold comets towards the star. Again, this would seem to be a perfectly reasonable explanation, you have the red dwarf as the culprit, we know from our own sun that Oort clouds exist and comets do get disturbed from them and head into the inner parts of solar systems.

But, then this theory fell short when sky surveys taken over the last century showed that the star doesn't just dim short term in dips, but has been dimming overall for a century. This would mean that you'd need a lot of comets in increasing numbers to account for this. The number needed is hard to swallow, on the order of 648,000 comets all orchestrated to pass in front of the star. That renders this explanation possible, but implausible, so other natural explanations are better candidates.

The problem is, every other theory involving a natural origin has some kind of Achilles heel that makes not fit very well. One theory is that the star is dimming and calming down after having recently ate a planet, but once again the chances of catching that just as it was happening are astronomical. It could also be some sort of material passing in the foreground, but we've never seen that sort of thing before and comes with its own set of problems.

So it boils down to this. Whatever we're seeing at Boyajian's star is a really rare phenomenon. If it's natural, whatever it turns out to be will be extremely interesting to science. However, if you have to resort to rare and unusual phenomena to explain something, there's one more possibility that might be consistent with what was being observed to occur at this star.

That would be gigantic alien megastructures. It is the least likely possibility, and has problems of its own. Where is the heat going that it too would radiate? Why is the rate at which it is blocking out starlight increasing? Is it under construction? But if so, how is it being constructed so fast?

The fact is, this mystery remains just as much of a mystery today than when the phenomenon first caught the public's attention. And the alien megastructure possibility still has not been discounted. So while it's very likely a rare natural occurrence causing this, the sticking power of the alien origin theory certainly raises eyebrows.

4. Life in the Clouds of Venus

If someone would have uttered that Venus might harbor microbial life just a decade ago, they'd have been called crazy. Venus seems, at first glance, to be a place unable to host life of any sort due being about as hostile of an environment as you can get on a planet. But in recent years, that's changed and there does indeed appear to theoretically be a way for life to exist in Venus' atmosphere.

The first indicator is Venus's history. Just after the late heavy bombardment about 4 billion years ago, Venus was not as it is today. Presumably, it would have been subject to the same amount of bombardment by comets that Earth and Mars were which would have delivered to it plenty of water. Venus would have been warm enough for that water to exist as a liquid. And while we aren't certain how long it might have had oceans, the estimates very wildly some going so far as to say 2 billion years.

The point is, there might have been plenty of time for microbial life to arise there. In fact, at that time in Earth's history single celled organisms were everywhere and actively oxygenating the atmosphere setting the stage for more than simple life.

But, if microbes did arise on Venus and water did persist for a long period of time, there might also have been enough time for them to adapt while Venus transformed itself into hell planet and become based in Venus's atmosphere in an area where the temperatures are earth-like and comfortable.

Coincidentally, in that same comfortable zone, there is some kind of material absorbing UV radiation. While there are some chemical possibilities to explain this, another possibility would be microbial life using the UV radiation as an energy source.

And, researchers have noted that the presence of sulfuric acid in Venus's atmosphere is not a showstopper for life. There is a way for life to coat itself with polymers known as S8 molecules to withstand the corrosive effects of the acid. As it turns out, S8 molecules have been detected in Venus's atmosphere.

So, it would seem, Venus may have just as good of a chance of having microbes as Mars does. It's certainly worth checking out, which seems to be on Roscosmos' agenda as they plan their next foray to the goddess planet.

3. Martian Meteorites

In 1996 a group of scientists from NASA announced that they had found structures that looked specifically like traces of microbial life in a meteorite known as Allan Hills 84001. It was such a sensation that Bill Clinton went on television and gave a speech about it.

This meteorite bears characteristics that solidly point to Mars as the rock's place of origin. That part isn't debated, it's a rock that was blasted off of Mars in impact. And it's an interesting rock, it appears to have been exposed to water in its past, as would be expected on Mars, and seems to have once been part of a subsurface aquifer. Such places on earth are often just right for life.

The problem with the claim was that these fossils, if indeed that is what they are which is still hotly debated, are significantly smaller than their counterpart microbes on earth, below the generally accepted limit thought possible for microbial life.

That's more than a little odd and gets into a debate about the existence of nanobacteria here on earth and those have been labeled the cold fusion of microbiology. And the debate over whether these structures in this and subsequently other meteorites linked with Mars are indicators of past life has never been settled. But it does remain a possibility, especially in light of the next case.

2. The Viking Biological Experiments

In 1976 NASA landed the first two probes to successfully function on the surface of Mars. Called Viking 1 and 2, they both functioned for years as stationary laboratories on the red planet taking high resolution images and doing soil analyses.

They were both highly successful as missions and greatly increased our knowledge of Mars. But the results of one experiment remain uncertain to this day, for good reason. The experiment tested positive for active microbial life on the surface of Mars.

Part of the problem was that this experiment directly contradicted another. The Labeled Release experiment showed that something was metabolizing nutrients in Martian soil samples. But, the other experiment was intended to determine if there was organic material in the soil, and it indicated that there was not. Metabolism without organics is not what you would expect from life, at least anything similar to Earth's microbes.

Now the labeled release experiment seemed to be a pretty reliable indicator. It was thoroughly tested on earth and never produced a false positive. Compounding this was the fact that both landers had the same experiments and both came up with the same results, despite being 4000 miles apart. It gets even stranger when you account for the fact that when the experiments were altered and done again after the soil was heated, the metabolic activity slowed, just as it would here on earth.

So that led scientists to look to nonbiological possibilities for the metabolism. There are several chemical processes that can mimic metabolism. One of these is formate which can produce a false positive. But it seems likely that Mars wouldn't have a lot of that, and the experiment where it produced a false positive did not have a corresponding sterilized control.

Another possibility is perchlorate, which Mars has been shown to have. The trouble is, perchlorate action does not slow down as you turn the heat up so the Vikings should not have seen a slowdown in metabolism when heat was introduced.

In 2013, a study showed that cosmic rays can make perchlorate break down. This yields hypochlorite the action of which would break down under heat and produce the false positive. But, proponents of the positive result being real, including the original researchers on the Viking missions, point out that hypochlorite hasn't been tested after long term storage of the material, which when doing that on Mars led to a negative result as though any bacteria present in the soil died off when stored. That leaves us without any solid non-biological candidates from which to produce the observed result.

Fast forward again. In 2014 Mars Curiosity detected the presence of organic molecules on the surface Mars. Why didn't the Viking experiments also detect organics if they were present? It turns out that Viking's gas chromatograph-mass spectrometer that was used to look for organics might not have been able to detect them at all and was never designed to look for life in the first place, and that was even stated by the head experimenter at the time in charge of the instrument. The plot thickens.

It has also been shown that the instrument would have required at least a million microbes to detect an organic signature. If there were fewer than that, the instrument would not detect their organics. To complicate things further, perchlorate destroys organic molecules and if it were in the soil, and if it were present at the Viking sites, well there goes the evidence for organics.

The bottom line here is that if these experiments had been performed on earth, where we unequivocally know that there is microbial action, the detection of life in the experiment would have not been questioned. Since they were performed on Mars, the bar is higher and it's difficult to imagine microbial life withstanding the harsh radiation environment of the surface of Mars, but on the other hand we've seen microbes here that can apparently use radiation in their environment to their advantage.

While a majority of scientists have not accepted this result, a vocal minority point out that life is the most likely explanation for the positive result in the Labeled Release experiment in so far as we know.

I don't know what to think either way, but this does qualify as very possibly having been a detection of life on Mars. I won't attach my usual caveat of "highly unlikely" to this one for the simple fact that we're looking to send humans to Mars and if there is any chance of alien microbes living there we need to know about them beforehand. More experiments are needed to answer question this once and for all.

1. The Wow! Signal

Topping the list, perhaps unsurprisingly, is the infamous Wow! Signal. It is perhaps the most unfortunate case, however, in that since it never repeated we are unable to study the nature of it and confirm whether it was really of alien origin. But even though it was detected in 1977, to this day no satisfactory natural or technical explanation for it has panned out and it remains the best candidate we've ever received for an artificial alien signal.

Part of the reason that the signal is so famous is that it bore all of the expected hallmarks of a signal sent by an alien civilization. And contrary to certain claims, the signal did not contain any message. It was just a continuous burst of raw radio energy at the hydrogen line, which is considered the most likely frequency aliens would use to say hello -- one that we on earth intentionally do not broadcast on in deference to SETI.

Now the telescope that detected the signal was stationary and relied on the rotation of the earth to scan the skies. Because of that, it was expected that any signal originating from deep space would be visible to the telescope for just 72 seconds. And the intensity of such a signal would rise for the first 36 seconds and then subsequently fall. Interference from earth would not do this, and both characteristics were present with the Wow! signal.

And, the bandwidth of the Wow! Signal was very narrow, which may further support the notion that it was artificial. Unfortunately, we don't know much else and the discoverer of the Wow! Signal, Jerry Ehman warns that we should not draw vast conclusions from half-vast data, so the origin of the signal is still open for debate. One should always be skeptical of anything that doesn't have confirmation, but out of all the potential signals that the various SETI efforts have detected over the years this is the only one where one could reasonably say "That may well have been it".