Original subtitles

[solemn piano music]

- [Narrator] Every once in a while,

archeologists, and sometimes amateur archeologists,

make remarkable and bizarre discoveries.

Sometimes the finding is so surprising

that they're unable to explain what it is they've found,

how it came into existence, or ascertain its value.

An out of place artifact

is an artifact of historical,

archeological, or paleontological interest,

found in a unusual context,

which challenges conventional historical chronology

by its presence in that context.

Such artifacts may appear too advanced

for the technology known to have existed at that time,

or may suggest human presence

at a time before humans are known to have existed.

Other examples

may suggest contact between different cultures

that is hard to account for

with conventional historical understanding.

We will explore these artifacts

and allow you to determine what you think they are,

their purpose, and who made them.

[eerie music]

[mid tempo rhythmic music]

Supporters regard these artifacts as evidence

that mainstream science

is overlooking huge areas of knowledge,

either willfully, or through ignorance.

Many writers or researchers

who've questioned conventional views of human history

have used purported artifacts

to attempt to bolster their argument.

Creation science

often relies on anomalous finds in the archeological record

to challenge scientific chronologies

and models of human evolution.

These artifacts have been used

to support religious descriptions of prehistory,

ancient astronaut theories,

and the notion of vanished civilizations

that possessed knowledge or technology more advanced

than that known in modern times.

[mid tempo music]

One such artifact that has gained mainstream attention

is the Antikythera device.

It is now known, it is a clock and astronomical computer.

It was found in a shipwreck off Greece,

so its exact age is unknown, but we know it is very old.

The device is very complicated

and has cogs that turn precisely

to track the sun and planets,

including planets that were not known to exist in antiquity.

Yet someone made this,

crafted it together, and designed it to be very accurate.

Modern reproduction models of this device are very precise.

Who made this?

How old is it?

Where was it used, and by whom?

It's one of the many questions historians tackle

as they study it.

So far, archeologists and science is baffled.

[mid tempo music]

Located at an altitude of approximately 1,170 meters

is the Beqaa Valley, Baalbek,

and it's known to have been settled from at least 700 BC,

with almost continual settlement of the town,

under the Temple of Jupiter,

which was a temple since the pre Hellenistic era.

However, some researchers, such as Graham Hancock,

argue that its roots go back as far as 12,000 years.

During the period of the Roman rule,

Baalbek was known as Heliopolis

and housed one of the largest and grandest sanctuaries

in the empire.

One of the most awe inspiring features of Baalbek

is the incredible megalithic foundations

of the Temple of Jupiter.

The temple was built on a platform of stones

that are among the largest building blocks seen

in the whole world.

27 of these enormous limestone blocks

can be seen at its base,

and three of them weighing about 1000 tons each,

known as the trilithon.

How they were cut so finely and moved into place,

has defied explanation,

particularly considering the blocks are known

to have weighed over 1000 tons.

Many researchers, Graham Hancock included,

reject the traditional explanation

that the blocks are the work of the Romans.

A visual study of the blocks

clearly shows a difference in style and appearance

between the large megalithic stones

and the surrounding blocks used to build the temple.

The gigantic blocks

used in the foundations of the Temple of Jupiter

are known to have come from a nearby quarry,

located about 2,600 feet from the temple.

The limestone quarry houses two massive building blocks

that never made it to the temple,

one weighing about 1,240 tons,

and the other, known as the Stone of the Pregnant Woman,

weighs about 1000 tons.

It's obvious these stones could not have been moved

using the knowledge and technology of the era,

even today with modern technology and modern machinery,

they could not be moved easily.

So why create monuments using these huge stones

when smaller stones would have been simple?

What technology did they use to move these stones

and how?

[atmospheric music]

Dogk literally means earthen figure,

they're small humanoid and animal figurines

made during the latter part of the JMmon period,

about 14,000 to 400 BC, of prehistoric Japan.

Dogk come exclusively from the JMmon period

and were no longer made in the periods thereafter.

There are various styles of dogk

depending on the exhumation area and the time period.

According to the National Museum of Japanese History,

the total number found throughout Japan

is approximately 15,000.

Dogk were made across all of Japan except Okinawa.

Most of the dogk have been found in eastern Japan,

and it's rare to find one in western Japan.

The purpose of the dogk remains unknown.

Due, in part, to the enigmatic nature of the figurines,

there have been numerous theories

of the nature regarding their ornate appearance,

with some speculating that the physical appearance

is connected to the suits and equipment

of modern day astronauts.

One proponent in particular, Erich von Daäniken,

has written how the dogk

has modern fastenings and eye apertures on its helmet,

an attribution made as part of the final chapter

of his 1968 publication, "Chariots of the Gods?".

There are also disparities in the varieties of dogk,

with only a portion of the figures

having the characteristic goggle-like eyes,

which are most cited by ancient alien theorists.

Were these depictions of ancient aliens?

Or simply fertility figurines?

Why did they appear in only one period

and then no longer seen?

What was their purpose?

Who did they represent?

[atmospheric music]

[uptempo piano music]

The Stone Doors in Hampi

are an impressive pair of monolithic doors

that were a part of one of the entrances

of the Royal Enclosure in Hampi.

Stone doors are one of the outstanding remnants

of the Vijayanagara duration,

that can be visible around many of the ruins in Hampi.

Though the huge doors are no longer connected to any shape

and aren't purposeful in any manner,

they do not fail to capture the interest of the traffic.

The Stone Doors in Hampi

had been a part of the Royal Enclosure.

The enclosure became a fortified area

that changed into the middle of the Vijayanagara Empire.

Some speculate these doors were not carved,

but rather poured and molded into shape.

What technology was used to create these stone doors?

And why use stone,

when wood would have been lighter and easier to move?

[atmospheric music]

Though not ancient, this very old cloth is interesting.

The Shroud of Turin is a length of linen cloth

bearing the negative image of a man.

Some claim the image depicts Jesus of Nazareth

and the fabric is the burial shroud

in which he was wrapped, after crucifixion.

The existence of the shroud

was first securely attested to in 1390.

The artifact is kept in the Cathedral of Turin,

in Turin, Piedmont, northern Italy.

The Catholic Church has neither formally endorsed

nor rejected the shroud,

but in 1958, Pope Pius approved of the image

in association with the devotion to the Holy face of Jesus.

Pope John Paul the second, called the shroud

a mirror of the Gospel.

Other Christian denominations,

such as Anglicans and Methodists,

have also shown devotion to the shroud of Turin.

Diverse arguments have been made

in scientific and popular publications,

claiming to prove

that the cloth is the authentic burial shroud of Jesus,

based on disciplines

ranging from chemistry to biology and medical forensics,

to optical image analysis.

In 1988, three radio carbon dating tests

dated a corner piece of the shroud from the Middle Ages,

between the years 1260 and 1390.

Some shroud researchers have challenged the data,

arguing the results were skewed

by the introduction of material from the Middle Ages

to the portion of the shroud used for radiocarbon dating.

The image on the shroud

is much clearer in black and white negative,

first observed in 1898,

than its natural sepia color.

A variety of methods have been proposed

for the formation of the image,

but the actual method used

has not yet been conclusively identified.

The shroud continues to be both intensely studied

and controversial.

Is this the face of Jesus, or a clever forgery?

To this day,

no one knows what technology could have been used

to create it,

whether a genuine image of Christ or a forgery.

[eerie music]

[tense music]

Today, there is an artifact you can clearly see yourself,

it's in Antarctica,

and some say it depicts the face of an alien.

With Google Earth,

you can see and zoom in on the face, easily.

Instagrammer, ufo scandinavia,

located, what many believe to be,

a massive alien face on the white continent,

using Google Maps.

It's indeed there,

is this pareidolia or an ancient monument of an alien race?

Study these images

or view them for yourself on Google Earth.

[atmospheric music]

Perhaps the most famous and enigmatic crystal skull

was, allegedly, discovered in 1924, by Anna Mitchell-Hedges,

adopted daughter of British adventurer and popular author,

F.A. Mitchell-Hedges.

Mitchell Hedges claimed that she found the skull

buried under a collapsed altar

inside a temple in Lubaantun,

in British Honduras, now Belize.

The skull is made from a block of clear crystal

about the size of a human cranium,

the lower jaw is detached.

In the early 1970s, it came under the temporary care

of freelance art restorer, Frank Dorland,

who claimed, upon inspecting it,

that it had been carved

with total disregard to the natural crystal axis,

and without the use of metal tools.

Dorland reported

being unable to find any telltale scratch marks,

except for traces of mechanical grinding on the teeth,

and he speculated that it was first chiseled

into rough form, probably using diamonds,

and the finer shaping, grinding, and polishing,

was accomplished through the use of sand

over a period of 150 to 300 years.

He said it could be up to 12,000 years old.

The skull was examined

at Hewlett-Packard's crystal laboratories

in Santa Clara, California,

where it was subjected to several tests.

The labs determined, only, that it was not a composite

as Dorland had supposed,

but that it was fashioned from a single crystal of quartz.

They also established that the lower jaw

had been fashioned from the same lefthanded growing crystal,

as the rest of the skull,

no investigation was made by Hewlett-Packard

as to its method of manufacturing or dating.

As well as traces of mechanical grinding on the teeth,

noted by Dorland,

Mayanist archeologist, Norman Hammond,

reported that the holes,

presumed to be intended for support pegs,

showed signs of being made by drilling with metal.

Anna Mitchell-Hedges refused subsequent requests

to submit the skull for further scientific testing.

The earliest published reference to the skull

is in the July, 1936 issue

of the British anthropological journal, "Man",

where it is described

as being in the possession of Sydney Burney,

a London art dealer,

who is said to have owned it since 1933,

no mention was made of Mitchell-Hedges.

F.A. Mitchell-Hedges mentioned the skull only briefly

in the first edition of his autobiography,

he claimed that it is at least 3,600 years old

and, according to legend,

it was used by the High Priest of the Maya

when he was performing esoteric rights.

It is said that when he willed death,

with the help of the skull,

death invariably followed.

In a 1970 letter, Anna also stated

that she was told by the few remaining Maya,

that the skull was used by the high priest to will death.

For this reason,

the artifact is sometimes referred to as The Skull of Doom.

Anna Mitchell-Hedges toured with the skull from 1967,

exhibiting it on a pay per view basis,

she continued to grant interviews about the artifact

until her death.

In her last eight years,

Anna Mitchell-Hedges lived in Chesterton, Indiana,

with Bill Homann, whom she married in 2002.

She died on April 11th, 2007.

Since that time,

the Mitchell-Hedges skull has been owned by Homann,

he continues to believe in its mythical properties.

Who made this skull?

How was it made, and for what purpose?

To date, no one is absolutely sure.

[eerie music]

The Nazca Lines are a group of very large geoglyphs

formed by depressions or shallow incisions

made in the soil of the Nazca Desert, in southern Peru.

They were created between 500 BCE and 500 CE,

and no one knows their purpose.

Most lines run straight across the landscape,

but there are also figurative designs of animals and plants

made up of lines.

Some of the Nazca Lines form shapes

that are best seen from the air,

the shapes are usually made from one continuous line.

Because of its isolation

and the dry, windless, stable climate of the plateau,

the lines have mostly been preserved naturally.

As of 2012, the lines are said to have been deteriorating

because of an influx of squatters inhabiting the lands.

The figures vary in complexity,

hundreds are simple lines in geometric shapes,

more than 70 are zoomorphic designs of animals,

such as a hummingbird.

Other shapes include trees and flowers.

Scholars differ in interpreting the purpose of the designs,

but in general,

they ascribe religious significance to them.

Who drew these enormous lines

that can only be seen and interpreted from the air?

Why design, what clearly appears to be runways and symbols?

Were these guideposts for an alien race,

or landing areas for some prehistoric civilization

now lost to man?

[atmospheric music]

It can be hard

to resist the allure of a mysterious object

found in a context that doesn't seem to make rational sense,

suggesting that it's proof of time travelers,

lost civilizations, or alien visitors.

You don't have to be a conspiracy theorist

or cryptozoologist,

to marvel at a bizarre computer-like device

that dates back to ancient Greece,

or a 2000 year old battery

found outside of Baghdad in the 1930s.

So-called out of place artifacts

are often said to baffle scientists

and conspiracy theorists.

They suggest that scientific efforts

to identify their origin and purpose,

willfully ignore potentially controversial explanations

outside the mainstream.

After all, it's true enough

that science is constantly evolving

and we still don't have the answers

to many of life's mysteries.

But imagine how everyday objects from our own time

might be interpreted thousands of years from now,

if information about how they're used doesn't survive.

A lot of artifacts become out of place

because their original context

might have provided important clues,

but the object was moved and that context is lost.

When we're so far removed from the original circumstances

in which a historical object was created,

it's easy to let all sorts of things

cloud our conclusions

about what those objects represent.

How do you explain a sarcophagus lid

that appears to show a spaceship,

primitive sculptures that look like airplanes,

or cave drawings, resembling astronauts in spacesuits?

Some proponents

of the ancient astronaut or ancient alien theories

pose that intelligent extraterrestrial beings

visited earth thousands of years ago

and made contact with humans,

potentially influencing their technology.

These visitors might have been misinterpreted as gods,

the theories muse.

The supposed proof of these theories

lies in drawings like the petroglyphs of Valcamonica, Italy,

which depict figurines with helmets around their heads

that could just as easily be ceremonial head dress,

or have some other more down to earth explanation.

Ancient astronaut proponents,

also cite artifacts like a Mesopotamian cylinder seal,

that sort of looks like a spaceship,

since it's just hovering there.

Although the first use of linear perspective

wasn't seen in art until the 14th century,

so the position of objects on a field

and in ancient composition,

doesn't necessarily mean anything significant, or does it?

A 1968 bestselling book by Erich von Daäniken,

interprets imagery on the lid of a stone tomb

belonging to Pascal the Great,

a Mayan ruler who died in the year 683 CE,

as a depiction of extraterrestrial influence

on the ancient Maya.

In the center of the frame is a man sitting,

bending forward,

he has a mask on his nose,

he uses his two hands to manipulate some controls,

and his left foot is on a kind of pedal

with different adjustments.

The rear portion is separated from him,

he is seated on a complicated chair

and outside of this whole frame,

you see a little flame-like exhaust.

Or Pascal could be sitting on a pillar

in front of a stylized temple,

among many other plausible explanations.

What all of this shows us

is the extent of which wishful thinking

can alter our interpretations.

It's obvious how the helicopter hieroglyphs,

found in Abydos, Egypt, got their name,

those images really do look like modern aircraft.

Then there's the Saqqara Bird,

a sculpture made of sycamore wood

discovered during the 1898 excavation of a tomb in Egypt,

which dates back to about 200 BC.

Some people have suggested that it might be evidence

that ancient Egyptians developed the first aircraft

many thousands of years ago,

possibly with the help of aliens.

The Quimbaya artifacts

a collection of tiny golden figurines found in Colombia

and dated to around 1000 CE, look a lot like flying objects.

When it comes to investigating out of place artifacts,

the best tool might be Occam's razor,

the principle that the simplest explanation

is most likely to be correct.

The simple explanation for all these objects

is that we've taken a lot of inspiration

from our airplanes, helicopters, spaceships, and drones

from nature, and abstracted birds look a lot like planes.

Archeologists say The Quimbaya artifacts

are just highly stylized birds, insects, and amphibians.

The function of the Saqqara Bird is unknown

because very little documentation of the period survives,

but no credible evidence of Egyptian aircraft

has ever been found.

The Klerksdorp spheres,

discovered by miners in South Africa,

seemed like they had to be manmade,

owing to their, supposedly perfect, proportions,

but they're estimated to be 2.8 billion years old.

Does that mean that they're evidence

of advanced prehuman civilization on earth,

whether some other species from this planet

or extraterrestrial?

As suggested by Michael Cremo,

author of "Forbidden Archeology:

The Hidden History of the Human Race".

Though they certainly look hand-carved,

these spheres are far from perfect

and most geologists agree

that they were naturally formed as concretions,

formed in volcanic sediments or ash.

The grooves were likely produced

due to the very impermeability of the layered sediments,

in which the stones were formed.

When the aforementioned Baghdad Battery

was discovered in modern Iraq,

it was really just three distinct objects,

a fired ceramic container, an iron rod,

and a bit of rolled sheet copper.

An assistant at the National Museum of Iraq, at the time,

thought it looked like a primitive galvanic cell

and theorized that it was used for electroplating gold

onto silver objects.

About a decade later, a man named Willard Gray

made a reproduction of the objects,

put them together, and filled the vessel with grape juice

to prove its conductive properties.

To the surprise of pretty much no one,

a lot of, supposed, out of place artifacts

are just forgeries and hoaxes.

When images of a clay object

resembling a modern mobile phone emerged online in 2015,

along with the explanation

that it was discovered during a dig in Austria,

eager theorists

were quick to declare it's obvious evidence of time travel.

As it turns out, the Babylonokia

is a sculpture by German artist, Carl Weingaärtner.

But what about enduring mysteries

like the Antikythera mechanism,

which is believed to be an ancient Greek analog computer

used to predict astronomical positions and eclipses?

Humans of ancient Greece

and roughly concurrent societies,

might not have had cars, air conditioning, or WiFi,

but their technology was often more advanced

than many of us imagine,

all sorts of things could have been developed, used,

and then forgotten, as civilizations rose and fell,

and so much of that all important context

disappeared over time.

Archeology is a puzzle,

and without all the pieces, we're often just guessing,

which is why it's important to note

that scientific consensus can shift and change too.

Few conclusions are fully set in stone, so to speak,

we never know when we might receive new information

that changes our perceptions.

[ambient music]

The popularity of the ancient alien architect theory

has grown to great prevalence,

this popularity must be mostly attributed

to the televised phenomenon

of shows such as History Channel's, "Ancient Aliens."

Some sources of information on the topic

are found on websites

such as theancientalien.com

and archeology books

like Graham Hancock's "Fingerprints of the Gods"

and Andrew Collin's "Gobekli Tepe: Genesis of the Gods".

No matter the popularity of the theory,

it is indeed extraordinary.

The belief in the ancient alien architect theory

defies all bounds of modern scientific knowledge,

rejecting traditional accepted requirements

for a legitimate scientific theory, sometimes.

There's no physical or historical proof

that provides a definitive evidence to support the theory,

and yet it holds.

No matter your personal opinion on the theory,

it is undeniably rampant, controversial, and extraordinary,

and it may very well be true.

For those who hold stock

in the ancient alien architect theory, explanations abound.

For example, at the time at which so many

of the ancient monuments in question, were built,

our perception of the necessary technology was not invented.

This begs the question as to how our ancestors

managed such a feat.

Additionally, many of the monuments, Egyptian pyramids,

Easter Island heads, et cetera,

have curiously precise alignments with the stars

and patterns of the sun.

Without telescopes or geometric equipment,

this type of precision seems highly unlikely

for humans to muster on their own.

Interpretations of cave etchings and hieroglyphics

seem to reveal images of helicopter-type vehicles

and structures reminiscent of a flying saucer.

Had our ancestors

not been visited by ancient alien architects,

how and why would these images appear?

Lastly, there is undeniable similarity

between structures

that were built hundreds and thousands of years

and miles apart.

Without ever having seen these other locations,

how did our ancestors duplicate them?

To those who accept the ancient alien architect theory,

it seems that the only logical explanation

to these mysteries,

was the visitation of higher intelligence race of aliens.

On the other hand, there are many

who reject the idea of the ancient alien architect theory.

From a technological standpoint, it is true

that scientists are still working

on figuring out how exactly

our ancestors managed such large architectural feats.

However, modern discoveries and research

has uncovered explanations and theories

based in legitimate scientific process.

For example,

a recent study, based out of Egypt,

led to the discovery that water can be utilized

to make the transportation of heavy blocks easier.

This sheds light

of the question as to how our ancestors

managed to move such heavy objects

without modern day technology.

Circumpolar stars, such as Polaris,

and lines of rope, could have been utilized

as a method of aligning the buildings so precisely,

with star patterns.

While scientists and archeologists

acknowledged that these actions would have been difficult,

they would not have been impossible.

Documents and building plans

have been found in places such as Egypt, as well,

describing the large workforces utilized in these projects.

For those who reject the theory,

they see no actual evidence of its claims,

they seek proof

in traditional and logical scientific process.

Those who believe the ancient alien architect theory

are not alone,

believers come from every walk of life,

every age, and every socioeconomic status.

There is a social fascination with the topic

and it is widely popular across many platforms.

Social media, television shows, blogs,

and even support groups devoted to the theory,

allow believers to hold strong.

The prevalence of the show, "Ancient Aliens,"

undoubtedly attracts many to this theory,

movies like, "The Day After Tomorrow"

and "Independence Day",

while not focused primarily on ancient architects,

promote fascination with alien conceptualization.

All of these platforms make it hard to ignore the topic

and allow believers more and more outlets

to solidify their convictions.

[ambient music]

When considering the psychological explanations

that may account for belief in such a theory,

a few come to mind.

Ad ignorantiam refers to the idea

that something must be true, if it's not proven false.

This is key in the mind of a believer,

instead of saying let me show you proof,

they instead say, show me proof this isn't true.

Hasty generalization is key as well,

jumping to a conclusion based off insufficient evidence

is found in nearly every claim

within the ancient alien architect theory,

this ties in with the slippery slope ideas as well.

A small idea's conjectured

and instead of analyzing or trying to disprove it,

the idea snowballs into an entire theory.

For example, when considering the issue

of how the pyramids were built,

some argue that hieroglyphics found onsite

resemble helicopters.

A believer assumes this to mean

that a helicopter type-vehicle was present

and since humans did not have that kind of technology,

they then assume that an extra terrestrial visitor

must have brought it.

And so, if they were present,

they must have been helping with the construction

of the seemingly impossible pyramid construction.

Instead of accepting alternate explanations,

a generalized theory is created

and seemingly explains the mystery.

These psychological explanations

account for why so many fall into this belief pattern,

it seems nearly impossible to reject an idea

when everything, seemingly, fits.

The characteristics of pseudoscience are tricky

and can make almost any issue believable,

humans seek explanation and the comfort of understanding.

When tackling an issue such as those ancient marvels,

it is natural to search for any explanation,

because it defies what we see as possible.

And this is where the ancient alien architect theory

gains so much attention, and how it continues to spread.

Just outside Cairo, in Giza,

the most famous of Egypt's pyramids rise from the desert.

Built more than 4,500 years ago,

the pyramids of Giza are monumental tombs

where ancient queens and pharaohs were buried,

but how exactly did the Egyptians build these things?

The great pyramid

is made of millions of precisely hewn stones,

weighing at least two tons each.

Even with today's cranes and other construction equipment,

building a pyramid as big as that of the pharaoh's,

would be a formidable challenge.

And then there's the astronomical configuration

of the pyramids,

which is said to align with the stars in Orion's Belt.

As well, ancient theorists

often point to the fact that these three pyramids

are, in a way, in better shape

than others built centuries later.

So, are Egypt's pyramids artifacts of aliens?

A huge circle of stones, some weighing as much as 50 tons,

sits in the English countryside outside Salisbury.

Known as Stonehenge, the neolithic monument

inspired Swiss author, Erich von Daniken,

to suggest it was a model of the solar system,

that also functioned as an alien landing pad,

after all, how else could these massive stones

have ended up hundreds of miles from their home quarry?

No one knows what exactly the meaning of Stonehenge is,

but as with all the other sites in this collection,

the explanation could be aliens.

Instead, scientists have demonstrated

it's actually possible to build such a thing

using technologies

that would have been around 5,000 years ago,

when the earliest structures at the site were built.

But would they know to do it?

It appears as though the stones

are aligned with solstices and eclipses,

suggesting the Stonehenge builders were, at least,

keeping an eye on the heavens.

[subdued piano music]

Teotihuacan, meaning the city of the gods,

is a sprawling ancient city in Mexico,

that's best known for its pyramidal temples

and astronomical alignments.

Built more than 2,000 years ago,

Teotihuacan's age, size, and complexity,

can make it seem other worldly.

Scientists suspect that, over centuries,

a mix of cultures, including Maya and Aztec,

built this city

that could house more than 100,000 people.

With its murals, tools, transportation system,

and evidence of advanced agricultural practices,

Teotihuacan is often considered

much more technologically developed

than should have been possible, in pre Aztec Mexico.

By far the most well known of Teotihuacan's buildings

is the massive pyramid of the sun.

One of the largest such constructions

in the Western hemisphere,

the pyramid's curious alignment

is believed to be based on calendrical cycles.

What inspired them to build this?

Could it have been an alien intervention?

[ambient music]

The enigmas surrounding the Moai,

Easter Island's fleet of large stone figures,

pretty much follows the same narratives

as the other sites described here.

How in the world did they wrap Rapa Nui

make these figures more than 1000 years ago?

And how did the Moai end up on Easter Island?

Carved from stone,

the, nearly 900, human figures

are sprinkled along the flanks

of the island's extinct volcanoes.

The figures average 13 feet tall and weigh 14 tons,

and appear to have been chiseled from the soft volcanic tuff

found in the Rano Raraku quarry.

There, more than 400 statues

are still in various states of construction,

with some completed figures awaiting transportation

to their intended resting place.

The reasons for carving the Moai are mysterious,

though they are likely sculpted for religious

or ritual reasons.

It's also not exactly clear

what happened to the Stone Age Rapa Nui,

but a leading theory suggests their civilization

succumb to an environmental disaster of their own making.

Nor do we know who or what inspired these creations,

aliens are also a plausible reason.

Outside the old Inca capital of Cusco,

a fortress rests in the Peruvian Andes.

Built from enormous stones

that have been chiseled and stacked together

like a jigsaw puzzle,

some say it could be the work of an ancient civilization

that had a little help from interstellar friends.

The 1000 year old interlocking fortress walls

are made of rocks that weigh as much as 360 tons each

and which were carried more than 20 miles,

before being lifted and fit into place

with laser-like precision.

How an ancient culture

accomplished such a feat of engineering,

is a little problem to solve.

In fact, it isn't the only example

of this intricate masonry,

similar walls exist throughout the Incan empire,

including one in Cusco,

where a 12 angled stone

has been carefully wedged into place.

Did aliens help with,

or inspire the creation of these monumental structures?

It's unlikely the Inca had this technology.

The evolution of technology

follows a pretty linear path, throughout history,

but sometimes we stumble upon artifacts

that challenge that perception

and throw those perceived timelines for a loop.

To some, these out of place artifacts

are none other than ancient alien technology,

providing our ancestors

were once visited by an advanced race,

while others maintain it's evidence,

we've underestimated the technological faculties

of our ancestors.

Growing up, most of us were taught

that the Egyptians built the pyramids

through primitive means,

using simple pulleys and brute force from slave labor.

But under deeper scrutiny,

this explanation doesn't seem to make sense,

and the same could be said

about the temple complex at Pumapunku in Bolivia.

The temple grounds of Pumapunku

are believed to date back to between 536 and 600 AD,

constructed by a civilization

appearing to have been wiped out by a cataclysmic event.

Pumapunku is part

of the larger well-known Tiwanaku Site,

an important location to the Incas,

who believed it is the cradle of their civilization,

characteristics ancient alien theorists

might consider significant as well.

This area is marked by a decorated megalithic archway

known as the Gate of the Sun

and, according to Freddy Silvia,

it may be one of the oldest temples.

Once home to somewhere between 10,000 and 20,000 people,

the name itself translates to navel at the center,

implying it once served as a cultural hub.

Atop the Gate of the Sun is a carving,

The Supreme God of the Incas.

[eerie music]

Silvia says the Viracocha and his ilk

were described as being much different

than the indigenous Incas,

they were white skinned, bearded, fair headed,

and capable of bending the laws of nature.

They were also significantly taller,

and these weren't descriptions of the conquistadors,

they didn't come along for about another century.

The reports of Viracocha's superhuman race,

make the anomalous stonework at Pumapunku

all the more interesting,

perfect 90 degree angles, precision cuts,

and immaculately even spacing in the stones were shocking,

considering the primitive epoch in which they were made.

Much of this craft stonework remains distinct to this day,

confounding scientists and archeologists alike.

[eerie music]

Earth is probably the last place you'd look

for extra terrestrials,

especially with all the new exoplanet discoveries

in the endless quest to prove there was life on Mars

at least once in the past, something billion years ago.

But are we looking too far?

Some scientists are less out there

and more down to earth, literally,

when it comes to finding traces of alien lifeforms.

Not that these hypothetical aliens

are actually crawling around our planet,

what these scientists argue

is that they may have dropped by before humans even existed

and left behind technosignatures, such as radios, rockets,

or other tech that might've been lying deep underground,

or floating around in space for eons.

Astrophysicist, John Wright,

has elicited more than a few eye rolls

with a controversial argument

that was recently published

in the "International Journal of Astrobiology".

He believes that technosignatures from an alien species

that landed not just on earth or the moon,

but even Mars,

before its atmosphere was obliterated,

or Venus before it became a swirl of toxic clouds,

could have possibly survived somewhere.

While Venusian clouds and volcanoes

would have long since eroded

and liquified any shred of evidence,

he still believes

it is possible something could be buried on earth,

Mars, or the moon,

if it hadn't, long ago, become space junk.

If a prior technological, perhaps space-faring species,

ever arose in the solar system,

it might have produced artifacts or other technosignatures

that have survived to present day.

[mid tempo music]

Meaning solar system artifacts

provides a potential path

to resolving an astrobiology question.

Wright doesn't believe aliens actually lived on earth,

and even if they had, erosion and ever shifting landmasses

would've turned any trace of them to dust.

Hypothetical alien trash

would have had a much better chance of surviving

in the sub surface of Mars,

away from the solar winds and radiation

it constantly gets blasted with,

and too deep to be smashed by meteorite impacts.

The Red Planet also has no plate tectonics

to crush any ancient computers,

or whatever they might've scattered around.

Other scientists are more skeptical,

possibly because we haven't yet

found any prehistoric ray guns or radio transmitters

next to a T-Rex skeleton.

Astronomy professor, Avi Loeb,

believes that there could have been a visit

from other civilizations on earth.

The search for extraterrestrial artifacts

is more likely to find technosignatures in space, though,

however unlikely that still is.

The most effective way to zoom in on something unusual

would be a sky survey,

whether we'd actually recognize something as alien,

even if we saw it as an entirely different thought

to keep both scientists up at night.

Supporters of the drive to find extraterrestrial artifacts

are already peering deep into space,

in a bid to discover cities, satellite networks,

or gigantic mega structures.

Some even think our own solar system

could contain probes sent by an advanced civilization,

wreckage from old spaceships,

or even evidence of ancient settlements

on planets like Mars or Venus.

Yet other experts slammed this headline,

grabbing easily sensationalized discipline

as entertainment science,

and question whether there's any point

looking for such tiny needles

in the mega haystack

of our breathtakingly gigantic universe.

Avi Loeb,

chair of the Harvard University Astronomy Department,

is among the world's most respected astrophysicists.

He stunned the scientific community

by refusing to rule out the possibility

that a strange cigar shaped object,

which sped through our solar system,

may have been alien in origin.

Astronomers named the space rock Oumuamua,

Hawaiian for scout,

and said it was an interstellar visitor,

which formed in another star system

before traveling here, through the void of deep space.

He did not simply dismiss the idea

that it was built by an extraterrestrial civilization,

and suggested it could have been a lightsail craft,

calling on his fellow scientists to keep an open mind

about its origins.

What sort of alien technology

are astronomers searching for right now?

Well, examples include artificial light,

industrial pollution, or reflection of starlight

from solar cells on the surface of planets

around other stars, mega structures,

or fleets of satellites.

Space archeology, with our best telescopes,

might reveal technological equipment floating in space,

similar to the two Voyager probes that we launched,

and are now leaving the solar system.

But we should keep in mind

that the travel time is very long between stars,

it would take the Voyagers about 100,000 years

to reach the nearest stars to our sun.

The equipment could therefore be defunct

if it belongs to a civilization that died by now.

The artifacts we're most likely to find

include the defunct debris

of highly sophisticated technologies,

which could be the wreckage of alien spaceships.

Perhaps our best way to put our hands on them

is to find objects that collide with earth

and survive as meteorites.

Is the truth out there?

When astronomers peer out into deep space,

in search of alien technology,

they're often looking for big objects,

such as a Dyson sphere,

a theoretical Death Star style space station

built around a star to harvest its energy.

A civilization capable of building a Dyson sphere

would have to be highly advanced,

because it would take decades, or even centuries,

to build such a structure.

Jason T. Wright,

associate professor of astronomy and astrophysics

at Penn State University,

became world famous after speculating

that the mysterious behavior

of a distant sun called Tabby's Star,

was caused by a mega structure moving in front of it,

although this hypothesis has been dismissed.

The idea that we should look, scientifically,

for evidence of alien technology in the solar system,

goes back to Ronald Bracewell in 1960.

Although, of course, people have speculated

about Martians, and such, for centuries,

he said, just 100 ago, it was totally reasonable

for scientists to discuss the possibility

of technological life on Mars.

In the '60s,

the Mariner probes showed that the Martian surface

has no obvious signs of large technology,

and so people assumed it, and the rest of the solar system,

must not have any sort of technology on it at all.

But no one has put scientific numbers to that assumption,

how much of the solar system have we checked?

Sure, we can rule out the existence

of big cities on nearby planets,

but what about smaller things?

How long would something last on the surface

before we would not recognize it as technological?

The search for bigger structures out in space,

requires a different strategy.

Finding artifacts outside the solar system

is all whole different matter.

In that case, we would not be looking at images of things,

but perhaps for the heat it gives off,

or its shadow as it passes in front of a star.

These sorts of artifacts would have to be tremendously huge,

bigger than earth, for us to even notice them.

Space is large, so if we find something around a star

1000 light years away,

our radio waves haven't even gotten to them yet.

Even if we do ever set up communication,

it will be thousands of years between messages,

so contact will be pretty limited and slow.

However, Wright does believe

that if we do find signs of an alien civilization,

then it's probably still alive.

[ambient music]

On a cosmic timescale,

things don't tend to last very long

after their creators or maintainers go away,

so what about the possibility of finding alien probes

near the earth?

There's no reason to think that such probes

couldn't be constructed,

but you would have to build an enormous number of them

for us to notice one flying through the solar system.

There are hundreds of billions of stars in the galaxy

and if there aren't artifacts moving among those stars,

they will spend most of their time in deep space,

where no one would ever notice them.

For one

to just happen to be passing through the solar system

around now,

there would have to be

thousands of trillions of trillions of them

throughout the galaxy.

But sure, it's possible to build that many machines.

If they are, what are called Von Neumann machines,

Johnny Von Neumann was a scientist

who discussed the implications of building a machine

that could build a copy of itself.

If you build one of those in space on an asteroid,

the idea goes that it would build a copy of itself,

then those copies would build copies.

Eventually they'd run out of asteroids altogether

and would have to move on to somewhere else.

If they could go between stars,

then at each star,

they would turn all the asteroids into more copies.

With a scheme like that, you could eventually have enough

that would be everywhere.

Despite our best efforts,

humanity has so far failed to discover

even the most basic form of alien life.

Dr Paul Davies, a professor at Arizona State University,

is author of "The Eerie Silence:

Searching for Ourselves in the Universe".

His book grapples with the Fermi paradox,

an argument which discusses the contradiction

between the high likelihood

that aliens live somewhere in the universe,

with humanity's inability to find them,

which is often called the great silence.

He has previously called for a search of the moon

to look for traces of aliens,

as well as discussing the possible existence

of a shadow biosphere on earth,

populated by undiscovered creatures,

which behave very different to all other known forms of life

on our planet.

[eerie music]

Searching for alien artifacts on the moon is possible,

if there was alien technology in the solar system,

this is a good place to look,

because the lunar surface is relatively stable.

We search right here on earth for artifacts

in the genomes of terrestrial organisms.

This might be as simple

as a message uploaded into the DNA sequence of a microbe,

human scientists now do this all the time,

or in the existence of a shadow biosphere

implanted here, say 100,000,000 years ago.

However, there is a risk

that we might not even recognize alien life or technology,

if we discovered it.

[slow techno music]

From ancient artifacts

to monuments and structures on our planet,

as well as others, seem to suggest, we are not alone,

and mankind has been visited

and influenced by extraterrestrials.

Perhaps one day we will be able to travel back in time

and see where such structures and artifacts came from.

But still then, we can only massage the science

and try to understand the technologies that once existed,

or determine if they were inspired by someone else.

We live in a wondrous world

with mysteries and questions all over the globe,

but when it comes down to it,

the only real question, is what do you believe?

Did aliens inspire or even create

some of the curious structures

and artifacts we're continuously finding?

Or is it man, himself,

more intellectual than we have ever considered?

The answer to our questions may not be in the stars,

but rather right here, on our own planet earth.

- [Announcer] 10, nine, transmission sequence starts,

six, five, four,

three, two, one, zero.

[dramatic music]

[upbeat music]