NARRATOR: Mali, Africa, 1931.
French anthropologist Marcel Griaule
treks through the forbidding desert in search
of the mysterious Dogon tribe.
When he finds them, he becomes fascinated by their culture
and traditions.
As Griaule starts collecting Dogon legends,
he notices an eerie similarity to ancient tales
found across the globe--
tales of amphibious gods, in this case,
called Nommo, who came from the sky, lived in the sea,
and helped mankind.
They describe these Nommos as being very mermaid-
or merman-like, but bequeathing lots
of knowledge of astronomy, math, and science
to this ancient race.
The Dogon would say that the Nommo were
these extraterrestrial gods.
But they needed a watery environment to live in,
though they could come on land.
NARRATOR: Griaule learns that their arrival is
known as the Day of the Fish.
GIORGIO A. TSOUKALOS: The Dogon actually said, well,
this was our creator god, Nommo, who descended from the sky
in a loud whirlwind of a storm of thunder,
smoke, and lightning.
NARRATOR: But what struck Griaule--
and shocked the world--
weren't the Dogon legends themselves,
but where they said their amphibious gods came from--
a star that no one on Earth knew existed
until 1862, long after the Dogon claimed
they knew of its existence.
DAVID CHILDRESS: In the 1930s, when French anthropologists
were first discussing the Nommo with these Dogon priests,
the Dogon priests said that the Nommo were coming
from the star system of Sirius.
Well, the French anthropologists were amazed at that
and were confused as well.
According to the Dogon, their gods
didn't come from Sirius A, a star that is clearly
visible in the evening sky, but from its tiny companion,
a dying star, called Sirius B, that
can only be seen with advanced, high-powered telescopes.
Sirius A is the brightest star in the sky,
because it is very luminous, and it is
also fairly close to the Earth.
In astronomy, it is a known fact that there is a Sirius A
and a Sirius B. Sirius A can be seen,
and Sirius B, for us, is invisible,
because it's just too small.
Now, the Dogon knew about the invisible companion star
to Sirius.
How did they know?
NARRATOR: For thousands of years,
Sirius A has played an outsized role in the imagination
of Greeks, Persians, Hindus, Romans, Polynesians,
and countless others.
The Egyptians even based their calendar on Sirius A.
And some believe they aligned the Giza pyramids to Orion's
belt, which points to Sirius A.
BILL BIRNES: Villages along the Nile and along the Euphrates
in ancient Mesopotamia--
they lined up their village dwellings
to mimic the constellation in which Sirius sat.
Sirius is one of the closest stars to us.
It's 8.6 light-years away.
Unlike the sun, which is a beautiful golden color,
Sirius is a bluish-white color, indicating it's much hotter
than the surface of the sun.
And that corresponds to it being more massive than the sun
and burning hotter.
It'll have a shorter lifespan.
NARRATOR: But how could the Dogon
have known about the existence of Sirius B?
Could they have, at one time, been in possession
of advanced technology?
Or could there be another, even more profound, explanation?
JOHN BRANDENBURG: The Dogon had an amazing degree of knowledge
about the Sirius system.
They knew that the orbits of the two stars
were about 50 years' period and that the invisible star was
very dense and past its prime.
They also knew that the brighter one
was a larger star than the sun.
NARRATOR: The Dogon also knew that Sirius B is about the size
of Earth and spins on its axis.
GEORGE NOORY: There is no logical explanation
for why the Dogon tribe knew about the Sirius star system
naturally.
We didn't have telescopes in those days.
How did they know this?
It's as if an ET came here and just told them all about that.
It's an amazing story.
MICHIO KAKU: One theory is, maybe the aliens
gave them this knowledge.
It can't be ruled out.
That's one possibility.
Because they got it right on the dot.
NARRATOR: But if a race of amphibious Nommo
came from Sirius B and gave the Dogon such gifts of knowledge,
did they only visit this one desert tribe?
Or did they visit other peoples in other lands?
GIORGIO A. TSOUKALOS: It would be
one thing if there's only one legend of a fishman worldwide.
But the Nommo is one story of dozens of amphibious bringers
of knowledge to our ancestors.
The ancient Hindus talk about this.
The ancient Greeks-- they all had these fishpeople that,
during the day, taught mankind, and then
at night, they wandered back into the ocean
to just emerge the next day.