One of the big questions that hangs over the UFO community
is the so-called Fermi Paradox.
If there's so much potential
for intelligent life in the universe,
why haven't we heard from anybody?
Well, one explanation is that the alien visitors
are like zoologist trying to study rare species in the wild.
They go to great lengths to go unnoticed
so they can observe without disturbing their subjects.
But now that we've developed
high-tech reconnaissance cameras,
it may be harder for them to stay hidden.
Which brings us to our next video.
It's November 2014, and the Chilean navy helicopter
is on routine patrol near the capital, Santiago.
The crew is testing out a forward-looking infrared,
or FLIR camera.
Something catches the technician's eye.
And when he points his camera, this is what he captures.
Two large, overlapping orbs.
Check it out. They're moving in unison.
Maybe they're even connected.
So we see here this is done in infrared.
Everything that's white is cooler,
and everything that is in black is much warmer,
or hot, or giving off a lot of heat.
(Host) Based on the thermal camera's readout,
the object is hotter than everything else in the frame.
And the navy crew says the object's speed
matches their own 130 knots.
Then look. The objects seem to release a plume of some sort,
not once but twice.
For forensics investigator Chase Kloetzke,
the plumes are an intriguing sight.
I've just never seen anything like this before.
And the plume. Like, what is that?
It's so unusual.
Is it gas? Is it vapor?
(Host) One thing Kloetzke is certain about,
the video is not a hoax.
(Kloetzke) This case is absolutely the real deal.
Chile, actually, openly investigates their UFOs.
So when the Chilean government comes out and says
"This is something that has the characteristics of a UAP,"
you can take it to the bank.
(Host) The Chilean government studied this video
for two years before releasing it to the public.
And this UAP, or unidentified aerial phenomenon,
didn't just look strange.
We have reports from the Chilean navy
that this aircraft did not appear on its radar system.
We also have a report that they did try
to communicate with this aircraft,
but it never responded back,
which is a bit of a mystery.
The Chilean camera could switch
between optical and infrared settings.
For an unexplained reason,
the plume that shows up as hot in the infrared
doesn't appear at all in the optical viewer.
To cut through all of these mysteries,
we turned the footage over to our experts.
Tim McMillian considers whether it might have been
a hostile craft trying to sneak into Chilean airspace.
Obviously the drone theory
is one that everyone has to examine.
This is filmed in 2014.
Drone technologies were not nearly as advanced
as they are today, and they weren't as frequent,
even with the militaries of the world.
So there's not really any shape
that would be consistent with
what you would expect to see from a drone.
(Host) Balloons are also mistaken for UFOs quite often.
So astronomer and video effects designer Marc D'Antonio
looks at that possibility.
Certainly balloons do go that high,
and certainly balloons do travel slowly.
But they generally don't show hot spots like this.
I do not believe this is a balloon.
(Host) The key could be those strange plumes.
D'Antonio thinks the object is moving through
pockets of moist air.
I have watched contrails start and stop
and make dashes in the sky.
I think this is a contrail from a commercial jet.
Two hotspots, two trails.
(Host) Others think the plumes could be a plane dumping fuel.
But wouldn't the two-year investigation
have tracked that plane down?
And the object appears to be headed towards Santiago,
a city of over four million people.
Aircraft, when they're in trouble,
will trend to go out to the ocean
to be able to dump their fuel.
They do that in non-populated areas.
And if you look at the settings on the west camera,
it was looking at an object that was fairly straight ahead.
Which means that the object was equivalent to its altitude,
which puts it at relatively low.
4,000 feet is nothing in terms of its altitude.
(Host) Airplanes only form contrails of ice
above 30,000 feet.
Hoffman sees why the Chilean authorities
still view this video as unexplained.
The Chilean video, as an object,
has all the appearances of being something
that we would think of something as being an aircraft,
but we just don't know for sure.
There are still no clear explanations
for why radar failed to detect this object,
or why the plume doesn't show up in the optical viewer.
But it's worth pointing out that the U.S. navy
only started seeing UAPs, like the famous Tic Tac,
when it installed its Aegis radar systems,
which the Chileans didn't have.
So, no one can identify what the Chilean navy
caught on video.
So we're going to call this a real UFO.
On a Friday evening in 2008,
geology professor Heinrich Frank
is homebound on the freeway
past the town of Novo Hamburgo, Brazil.
Something catches his eye at a construction site
on the side of the road.
Take a look.
The first tunnel I found was very, very small.
And when I entered, I see immediately
the claw marks on the walls.
(Host) Look closer.
Dr. Frank focuses on this,
grooves dug into the tunnel walls
and slashes in the surface.
What could have made these marks?
Dr. Frank's research dates the caves
to be about 12,000 years old.
And there's reason to think
they aren't just natural formations.
Taken a close look at them from a scientific point of view,
they don't appear to be natural caves
based on the types of rocks that they're being cut in.
Some of these rocks are much harder.
The easy rocks can be broke by water.
They also have a really weird shape,
that they're more horizontal than they are vertical.
Which tells me that something carved these tunnels out.
When you consider all the megafauna,
you have only two animals
with the necessary claws to build tunnels.
The armadillos and the sloths.
(Host) We're talking now about the Pleistocene era
which ended 11,700 years ago.
It was the age of megafauna,
gargantuan mammals like mastodons,
and in this case perhaps the famous giant sloth.
Could Frank have discovered some sort of ancient burrow?
Or could such an animal, believed to be extinct,
still be living there today?
(Frank) When you go inside the tunnels,
sometimes you feel like the animal
is on the next corner.
(Host) The fossil records show that Megalonyx sloths
were the size of present day bull elephants.
But throw in there massive claws on each forearm
used for defense, they roamed the Western Hemisphere
when humans first arrived.
One can only imagine how terrifying it must have been
to try to hunt these giant ground sloths.
In fact, there has been evidence found of these
giant ground sloths, the Mylodons,
that were actually trapped in a cave in Argentina
and corralled and kept as a food source
by primitive humans.
Giant sloths and humans together?
If it sounds like something out of a horror film
instead of history,
a recent find will change your mind.
At White Sands in New Mexico,
archeologists uncovered the prints of a giant sloth
being followed by humans.
They were stalking it.
So could these giants still be around?
Did they dig the Brazilian tunnels?
And if not them, then what did?
(Anderson) If you take a look at the tops of the ceilings
in one of these caverns,
you'll see that they're-- look like claw marks.
(Host) So geologist Bob Anderson thinks
some sort of burrowing creature made these caves.
And what if these animals still exist?
Archeologist Ed Barnhart says not so fast.
Well, some people have suggested
that these giant caves are actually
the holes and burrows.
Well, that's an interesting idea,
but show me the artifacts.
(Host) So far there's no proof.
No one has captured a giant sloth,
found a carcass or taken a single picture of one.
So I can take giant sloth right off the list.
(Host) And Barnhart even questions if giant sloths
ever dug these tunnels at all.
(Barnhart) Look down in this section here.
There's one, one, one.
There's one coming across here.
There is no reason to believe that these are claw marks,
because they would be repeatedly sections of three.
(Host) Barnhart makes a good point.
But if a giant three-toed sloth had uneven claws,
it might leave one, two or three marks
depending on how hard it was digging.
Still, Barnhart thinks it's more likely
the marks were created by an extinct worm-like creature
called a trilobite.
Some were predators.
The biggest weighed as much as 10 pounds,
and they were known to burrow into walls.
These are much more like worm casts
that were into the wall.
Trilobites make more sense to me
because those are individual hot-dog-shaped things
that attach themselves to the wall and dig in.
(Host) But hang on. As you can see,
there are distinct differences between these
confirmed trilobite tracks
and what we see in Dr. Frank's tunnels?
Is this case really closed?
Okay. It's true that no giant sloth fossils
have been found in Dr. Frank's tunnels.
But the marks don't look exactly like trilobite tracks either.
So we can't come down on one side or the other.
We're calling this an unexplained phenomenon
until we get further proof.
Buenos Aires, Argentina. April 2020.
Local media reports strange sightings of bats
that can swim and run on land.
One provocative online headline reads...
And here is their proof.
These humanoid-looking, bat-like creatures
appear to be swimming in a local lake.
Take a closer look.
What in the word can they be?
(screeching)
6,000 miles away, another freakish video
of more mystery bats, this time from China.
Watch as this one flops on the ground,
making unsettling vocalizations.
(screeching)
It's flopping around, it's screeching.
It's acting erratically.
It's actually kind of disturbing.
So it's fairly obvious why someone
would immediately look at this and think:
This is some kind of really strange,
weird-looking mutant bat.
(screeching)
(Host) Ambitious scientists have tried to create
custom hybrid species before.
Perhaps most famously the Soviet zoologist Ilya Ivanov
tried to cross an ape and a human back in the 1920s...
without success.
Are these swimming bats the result of some
recent genetic project?
Even normal bats have a complex relationship with humans.
Research suggests some viruses, like measles and mumps,
originated in bats.
But are the animals in these videos
really some kind of mutant?
We turned to our analysts.
I can see how this one looked particularly mysterious.
(Host) Marine biologist Dr. Shea Conger says
the theories about these creatures run the gamut.
There's some conjecture online that this animal
might be the mix between a bat
and something like a frog.
(Host) But she doesn't believe
that kind of cross breeding is possible.
To be able to mix two species that are so different
would be highly unlikely and wouldn't result
in something that would actually be alive.
(Host) So if this is not a mutant, what is it?
Wildlife biologist Lucy Eckersley
first focuses on the video out of China.
I don't think this is even a bat.
I think it's another type of mammal.
Something that's called a colugo.
Colugos are a type of gliding mammal.
They are also sometimes called gliding lemurs.
They can reach up to 200 feet
using this amazing area that's called a patagium
that folds of skin that reaches from the fore limbs
down to they hind limbs.
(Host) That might explain the Chinese video.
But what about these strange things
in the water in Buenos Aires?
I don't think that these are colugos.
I think what we're actually seeing is a marine animal
called a sea hare that we can see around the world
and can grow up to 15 inches long.
Both of these animals, I understand why people
might think that these are mutant varieties of bats
living underwater or looking like the strange animal
screeching on the ground.
But I can tell by looking at their anatomy
that what we have is a colugo and sea hares.
Again, it's important to know that many species
can share common characteristics and affinities.
But people, frogs, and bats have different DNA
and can't be cross-bred, at least not yet.
Our verdict? Colugos and sea hares.
It's March 2016, and the streets of Bogota, Colombia,
are swarming with traffic.
So it's no surprise that a group of bystanders on a bridge
started screaming when they saw this.
(woman screaming)
(horn honking)
Journalist Krissy Eliot had the same reaction.
Oh, my God!
(screaming on video)
I was like, "What is this guy doing?"
He got in between vehicles.
He lies underneath them. And then he just prances off.
(Host) Look again.
The daredevil pedestrian seems to possess cat-like reflexes.
Might there be a strain of super humans
with this kind of quickness?
It takes about a quarter of a second
for a human reflex to react.
250 milliseconds.
But there are people whose reaction time
is even faster than that.
(Host) People like speed shooter Bob Munden
who holds 18 world records.
He's been clocked hitting a target
and replacing the gun in his holster
within 175 milliseconds.
(Oluseyi) And this guy, if this is real,
his reaction time must be on the next level.
(Host) Perhaps something else is going on here.
Dodging traffic doesn't just take skill,
it takes will.
There are about 400 known cases
of something called Urbach Wiethe disease,
and what it does is it withers away at your amygdalae,
which is the part of your brain that is responsible for fear.
So could this guy who's cartwheeling through traffic
have this disease?
So we have two things to explain here.
The traffic dodger's lightning-quick reflexes
and his foolhardy fearlessness.
Our investigation begins not with the person
but with the footage itself,
as we turn to forensic video analyst Mick West.
What was strange to me was
not simply how daring this was,
but the fact that all the cars ignored him.
They weren't actually slowing down
or trying to stop or avoid him.
(Host) West's first impression tells him
this traffic dodger may not be what he seems.
But what clues are in the video?
(West) What I often look at in analyzing videos
is the lighting and the shadows.
We can see the whole setup.
There's this pole here.
Then there's this power pole.
And this is what's casting the shadows in the road.
So we know that that's an actual shadow,
and that's the shadow of the power pole.
So that should be obscured by the cars when they go by,
like the buses.
(Host) But watch closely as the bus approaches.
Two shadows appear to exist in the same place.
(West) Now, shadows don't add together like that.
If something is a shadow,
and then something else shadows it,
it eliminates the first shadow.
Because light doesn't go through things twice.
Which means that this isn't a real shadow.
It's just something that's been added.
It's overlaid on top.
(Host) That's not all West finds.
Take a look as this guy lays down in the street.
This car really doesn't look like it's big enough
to go over him, and I actually looked at the model of the car.
It's a Renault Twingo. A small car.
And the ground clearance is just under seven inches.
So it's about that much.
Which is impossible for someone to fit their head
in something that's 150 millimeters.
(Host) So it turns out seeing isn't believing.
Well, then how'd he do it?
West says the camera was locked down
at one position on the bridge.
If there had been no traffic--
So he would just wait until there was a gap in the traffic.
He would run out, do his stuff,
and then get to the other side.
(Host) Then by combining the solo acrobatics
with another shot of oncoming traffic
and some staged screaming,
you have one seemingly incredible super human.
All this adds up to it being a, uh, a forgery.
We contacted the creator of this video,
and he told us there's no problem
with his brain's amygdala.
He fears danger just like the rest of us.
But he did confirm one thing.
This video is two different versions
combined with digital effects
and an extraordinary imagination.