Physics in Space

Why Should We Colonize Other Planets?

An illustration of a space habitatSpace colonization has captured the public imagination.  Ever since the 1800s science fiction writers have been speculating about what it would take to reach other worlds.  The movies have visualized trips to those worlds in many different ways.  But so far poor mankind has only managed to send a few representatives to the moon, our nearest neighbor in the Solar System, and some probes out into the distant reaches of the Solar System itself.  We have two probes that have only just recently entered interstellar space.  But is all this effort worthwhile?  Should we really try to colonize other worlds?  Here are some reasons why we should colonize other planets.

We Should Colonize Other Planets for the Science

Every planet has a dynamic ecosystem or environment.  We have learned that they all behave in some similar ways, but there are strange differences between our world and the other bodies in the Solar System.  There are seas of frozen water just under the surface of Mars, seas of methane on Saturn’s moon Titan, puddles of frozen water at the poles on our own moon, and strange moving continents on the dwarf-planet Pluto.  All of these worlds act in according to our understanding of the laws of physics but each world has taught us something new about how those laws work.

We have learned that planets may be born with atmospheres but without adequate protection those atmospheres can be stripped away by the Solar wind.  Or if the atmospheres are not stripped they can become toxic environments.  The atmosphere on Venus is so thick it would crush you instantly if you could land on the surface of the planet.  But it is so toxic because it is composed largely of sulfur and carbon dioxide that it would choke you and burn you if you just passed through it without protection.

And yet scientists believe that both Mars and Venus may once have been very Earth-like with liquid water on their surfaces.  So what happened?  We think we know some of their stories but scientists want very much to study these planets close up.

We Should Colonize Other Planets to Grow our Civilization

Although people like to say that the Earth is running out of resources that is really not true.  We are consuming fossil fuels at a faster rate than the Earth can replace them, but as our technologies improve we’ll be able to move away from those fossil fuels and utilize cleaner, more efficient, more easily replenished fuel sources.  Wind and Solar power have become very promising sources of energy.

Nonetheless, we are using up all the easily settled lands on Earth.  And though we might convert vast desert areas like the Sahara and western Australia into green lands (as nature has done many times in the past), we struggle to agree on when and how to achieve these things.  Concerns about how we might damage the environment with planet-wide changes have introduced a hesitancy into our natural path toward human migration and settlement.

Colonizing barren worlds would give us the opportunity to experiment with environments where, so far as we can determine, no life exists.  By bringing life to other planets we’ll be able to continue growing our civilization.  Although some people like to project a humanity that outgrows the galaxy in just a few thousand years that prospect seems very unrealistic at the present time.  But as long as we continue to discuss the prospect we’ll be aware of our own growth through the galaxy.

Because of the many different personality types and value systems we hold as humans, expanding out to other worlds will give us room to come to terms with our differences.  One hopes that warfare would be less likely in space because it would, at first, be more expensive to fight with each other than it is on Earth.  Perhaps colonizing other worlds will help our civilization mature beyond warring within itself.

We Should Colonize Other Worlds for the Adventure

Every generation produces adventurous people who want to leave our cities behind and go explore nature.  But our rapidly shrinking wild lands make it more difficult for people to get away from civilization.  Colonizing other worlds creates new frontiers that can be explored and appreciated.

No doubt some people will want to keep the barren rocks and plains empty, but other people will want to explore new forests, swim in new lakes and rivers, and watch the sun set from new beaches.  Simply creating these forests, lakes, and rivers will be a great adventure.  Preserving them for the use and enjoyment of future generations will also be a great challenge.

We Should Colonize Other Planets to Ensure Our Survival

Human culture is closely associated with the demise of many large species of animals.  Even today we are slaughtering species at a faster rate than nature can evolve new species to replace them.  By transporting our ecosystem to other worlds we’ll increase the changes of survivability for many other species among plants and animals.  We can recreate ancient environments where huge herds of now extinct or near extinct animals can thrive.

But we’ll also ensure our own survival against stupidity and cosmic accidents.  We don’t know when another massive asteroid will hit the Earth and we still don’t have the means of defending the Earth from such a threat.  And many people also fear the prospect of nuclear global warfare.  It’s unlikely anyone would survive such a war.

By spreading our ecosystem and our civilization to other worlds we increase the chances that mankind will live to explore the stars, unlike the dinosaurs who vanished within 5 million years after a huge asteroid hit the Earth 65 million years ago.

But How Practical Is It to Colonize Other Planets?

Although we have many good reasons to spread out from the Earth, we still don’t yet have the technology to do this.  Mars and Venus are no more likely to be terraformed in the next 100 years than is Pluto.  And there are some problems we may never be able to solve, such as kick-starting Mars’ magnetosphere.  The magnetosphere is a magnetic field created by the rotating molten metal located at the Earth’s core.  Mars’ core is so small that it has already cooled down and all but stopped moving.  Scientists believe that the loss of its magnetosphere is why Mars has so little atmosphere left; the magnetic field is no longer strong enough to deflect the Solar Wind, which strips away atmospheric particles.

Venus still has a molten core but how could we possibly transform its atmosphere back into an Earth-like environment that is comfortable for humans and other Earth-life?  That topic is still firmly in the realm of science fiction.

What seems more practical today is the idea of creating space habitats that people, plants, and animals can share.  These habitats will orbit the Earth, the Moon, Mars, Venus, and probably other planets.  They can even orbit the Sun itself.

To build such habitats will require only minor advances in technology from where we are today.  But we still need a reliable and economical transportation system, preferably one that does not rely on dangerous chemical or nuclear fuels.  And we also need to be able to resupply these habitats with raw materials (including atmospheres) so that they can repair themselves and grow.

Space habitats will need to create their own artificial gravity, most probably through spinning in circles.  These habitats may take the shape of great wheels or spirals that turn slowly enough in space to simulate a 24-hour day, suitable gravity, and allow the free movement of small vehicles.

If we can build a space habitat that recycles its air, water, and food then we’ll only need to transport technological resources to it.  These habitats will become self-sustaining little worlds that people can enjoy for thousands of years to come until we’re ready to descend to terraformed planets and start new Earths.  And by then we will probably know how to travel to the stars as well.