Today, the moon waits for us to expand our vision.
The University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
For 20 years I've wondered
why we lost interest in the moon so quickly after
we first walked on it. Maybe it was because we
looked over the astronauts' shoulders and saw only
a great slag heap. Now geologist Donald Burt asks
if it's only that or more. Does the moon hold
riches, or is it just a scabrous wasteland?
We know a lot about the moon today. It's rich in
aluminum, calcium, iron, titanium, and magnesium.
There's also plenty of oxygen on the moon, but it's
all bound up in compounds that are hard to break
down. You can get at it, but it'll take a lot of
processing. Maybe we can pull some hydrogen and
helium-3 out of the rocks as well.
What's absolutely missing on the moon is anything
volatile. There's no water -- no loose gas or
liquid of any kind. The vacuum on the moon is more
perfect than any we've ever created on Earth.
So can we go after minerals on the moon? Before we
do, let's think about mining and smelting on Earth.
We use huge amounts of water -- huge amounts of
power. We consume oxygen and we put out great
clouds of gas. But there is no water on the moon,
nothing to burn, and no power until we put it
there.
Without water the moon hasn't been shaped the way
Earth has, with alluvial strata and deposits. Many
of its riches are all mixed together in the surface
layer of dust. We'll probably begin by surface
mining for oxygen to sustain our outposts in space.
Metals will be useful byproducts.
Pollution would be a terrible problem if we mined
the moon the way we do Earth. The moon's near
perfect vacuum is going to be useful in all kinds
of processing. If we dumped gases on the moon the
way we do on Earth, we'd ruin that perfection.
You see, most gas molecules move more slowly than
the lunar escape velocity. Only the fastest ones
get away. Now and then, slower ones are sped up as
they collide with each other. Then they also can
escape. Over the years, the moon loses any gas
released on its surface, but not right away. So we
have to invent completely closed processes to take
the moon's wealth. That way we'll protect one of
the moon's greatest resources -- its pure vacuum.
The moon is a rich place, but we must put our minds
in a wholly different space to claim its riches.
The moon will reclaim our interest as we learn to
see more than a slag heap. The moon has held our
imagination for millennia, but in a different way
each time our knowledge of it has changed. Today,
our vision of the moon is on the threshold of
changing yet again -- as we learn to look at it
with a process engineer's eyes.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
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