[music playing] NARRATOR: Humans have been
mesmerized by the moon since the dawn of man. And although many theories
have been proposed, scientists cannot
say with absolute certainty how this celestial
object came into being. When I was a
student, nobody really knew where the moon came from. But because it's so relatively
big, this was a real problem. And I think that
there is a tendency to think that moons get somehow
captured by the parent planets. If you've got one body here
and another body coming along, it can't just get trapped
into orbit like that. The difficulty there
is just basic physics. So this remained a puzzle
until about 20 years ago, when another theory came along. And that is that
proto-Earth was, very early on in the history
of the solar system, hit by a Mars-sized
body, hit obliquely that this Mars-sized body plowed
into the center of the Earth and became the Earth's core,
and a lot of the outer material got stripped off by this
gargantuan collision and coalesced to form the moon. Now, they had to come up with
a very bizarre theory for how the moon came into being because
all the conventional theories don't make any sense. The best theory of
the moon's formation is phantasmagorically
catastrophic collision of two things, you know,
at just the right angle to form this belt of debris
that then formed the moon. But the moon, its exact
size is such that it gives us total eclipses. Its disk exactly covers the sun. And the chances
of that occurring are so literally astronomically
small, it's very disturbing. NARRATOR: The sun's
diameter is 400 times greater than the moon. And coincidentally, the sun also
happens to be nearly precisely 400 times further away. This is the reason that
the sun and the moon appear the same size
in the Earth's sky, and why we on Earth can
experience eclipses of the sun. DAVID CHILDRESS: It's just
perfectly in that orbit to eclipse our sun. The odds of the moon
being in that orbit accidentally are
a zillion to one. So that right there is
evidence that our moon is in a perfect orbit around our
planet that's not accidental. MIKE BARA: In order to
have a solar eclipse, the moon has to be exactly
the size that it is, which is 2,160 miles. Not 2,161, not 2,159, but
2,160 miles at its equator. And there are people
out there that actually think that's a coincidence. The fact is is that
that is by design. NARRATOR: Throughout
our observable galaxy, this relationship and others
have not been duplicated. Other moons are sizeably
smaller by comparison to their mother planet. Earth's satellite not only
orbits closer than it should for its size, it is
also the only moon in the solar system that has
a near perfect circular orbit. And no other lunar
bodies are known to have such a stabilizing role
as the moon has with the Earth. WILLIAM HENRY: Recent
computer simulations have shown that, without
the moon's presence, the Earth's axis tilt
would be completely different than it is today. We might not even have seasons
as we know them presently. Without the seasons, it could
be very difficult for life on Earth. So the moon is
actually performing an incredible function. It's life-sustaining. Without it, we
might not be here. ALAN BUTLER: There are so many
peculiarities about the way the moon has affected the Earth
that one might be forgiven for believing that there
is intelligence behind it, that something made it that way. The moon is so strange,
so odd in terms of what we find elsewhere
in the solar system, and particularly in terms of
what it does for the Earth, having made the Earth
into a haven for life, that one feels obliged
to ask the question, could such things have
come about by chance? Was it placed
there deliberately? Was it engineered,
maybe by aliens? And therefore, is our whole
existence a planned event? [music playing]
