On the Ethics of Colonizing Mars and Space

Both the colonization of Mars and Space colonization has ethical concerns. In this post we will discuss some of the more important issues.

Possible Life on Mars

Similarly, nobody really mourns for those who do not exist on Mars, feeling sorry for potential such beings that they cannot enjoy life.

David Benatar, Better Never to Have Been. The Harm of Coming into Existence. 2006.

One of the arguments against colonizing Mars is concern for possible Martian lifeforms. Some people argue that introducing terrestrial life to the Red planet, would be bad for native Martian life. Most scientists believe that, if Martian life (still) exists, it will most likely consist of bacteria or similar organisms.

The question we should ask ourselves is whether such Martian bacteria has any moral standing. According to English philosopher Jeremy Bentham, beings have moral standing if they can suffer. Bentham’s student John Stuart Mill, has introduced another important principle in moral philosophy, the harm principle. According to this principle our liberty is limited by the liberty of others; we may do what we wish as long as we do not harm other beings.

If we combine Bentham’s axiom of suffering with Mill’s harm principle, we can conclude the following: we may not beings who have the ability to suffer. As far as we know, bacteria cannot suffer, therefore they have, according to Bentham, no moral standing. For this reason we cannot conclude that bringing terrestrial lifeforms to Mars is immoral, because native Martian life might became extinct.

A related argument is that if terrestrial lifeforms are introduced to Mars, the original lifeforms cannot be distinguished from the introduced ones. This would interfere with scientific research to life on Mars. Although this might be regrettable, we might ask ourselves whether this would outweigh the benefits which colonizing Mars would offer to humanity.

A third concerned with the possibility of Martian bacteria is the health risk for colonists. This fear is understandable, however it is quite unlikely. Infectious diseases are generally limited to certain organisms. So is HIV dangerous for cats, apes and humans, whilst crocodiles are immune for it. Because parasites are adapted to a certain host organism, they cannot infect other organisms. (This also implies that all stories about fighting alien invaders with biological warfare are implausible.)

Of course, there is one caveat to this reasoning. Martian microbes might be poisonous to us.

Environmental impact on Earth

Another concern regarding space colonization, is the environmental impact of rockets. This is a serious problem, the pollution due to launching rockets into space do damage to our atmosphere. This pollution has all kinds of harmful effects to people, not the least to public health. The harm principle dictates that we should reduce the impact of rockets.

The precise environmental impact of a rocket depends on its type, especially on the kind of fuel used. Many rockets use poisonous fuels such as hydrazine, a hydrogen-nitrogen compound. By burning hydrazine both water (H2O) and nitrogen n-oxides  are produced, especially the latter is problematic since they are one of the causes of acid rain.

Hydrogen rockets, which produce water vapour as exhaust, are the most environment-friendly type of chemical rocket. Although there some technical difficulties with managing hydrogen rockets, the space shuttle program has shown that these can be overcome. Water vapour is a greenhouse gas, in fact one of the strongest, however this gas also stays in the atmosphere for a short time.

On the other hand, space colonization will also solve some environmental problems. For instance, asteroid mining would eliminate the need for mining on Earth. And mining is one of the leading causes of environmental degradation.

The costs of space colonization

Space-flight is expensive and so is space colonization. Therefore some people argue that given the large amount of poverty in the world, it is wrong to spend billions of dollars to a space colonization programs. However, these people are unaware that space colonization might be a solution for the problem of poverty.

The Solar System contains a lot of resources, so much that John Lewis has calculated that an equal distribution of these resources, would give every human on Earth a 100 billion dollars, which is much more than Bill Gates’ net wealth. Of course, this is somewhat extreme and this calculation is based on current prices of resources. When asteroid mining will increase the supply of this resources, their prices will fall. However, this price fall is not bad, since materials will become cheaper and so will the general price level. In this manner poor people can do more with their money.

Further, space colonization might increase employment, both in Space and on Earth, by creating all kinds of jobs. Even if the direct employment as result of space colonization will be limited, there is also the possible increase of indirect employment. Employees in the space industry will demand all kind of goods and services, which will create many more jobs etcetera.


Space colonization faces several difficult ethical question, however, it is also a potential solution for some ethical problems such as environmental damage and poverty.

16 thoughts on “On the Ethics of Colonizing Mars and Space”

  1. Full speed ahead, Captain! I say. 3D food printers, Dyson Sphere’s, and space exploration/colonization are the only things that are going to save this human experiment.

  2. It appears the developers of this space travel and colonization have thought about everything including the ethical problems it may have. Interesting thoughts I must agree.

  3. Very Interesting and inspiring. Gave me thoughts 🙂
    I’ll post a similar article to continue my discussion on Mars, and I’ll talk about space colonization too. If you don’t mind, I’d like to give you credits and quote your article with a direct link.

  4. Nice essay!
    I like all of the points you bring up and I would like to add ethical problems due to the physical / social environment to the list. In a colony it would be likely that most privacy would be eliminated since one person’s actions directly impact the survival of the whole group. So I would imagine pretty extensive monitoring of movements and such in a mars colony. It would be important to know where everybody is for safety reasons.

    Also with a very limited number of people and the cost of resources it would be absolutely necessary that everybody pull their own weight. This could run afoul of some moral principles. For example it may not be possible to make accommodations for disabilities. Also it would cause problems for any criminal activities since the colony may not be able to support any form of incarceration.

    Next many things might need to be socialized in a colony. The structure, resources and everything would be necessary for the survival of everybody. So it would be important to ensure everybody has food, water, health care, shelter and clothing. This could be seen as immoral by some depending on their view.

    Finally social relationships directly effect the whole colony. If a colony is small then who is dating who is everybody’s business. That is because a relationship going bad could hurt the whole colony. It could damage the cohesiveness needed to stay alive. It could result in destruction of property which may be needed and not easily replaced.

    Basically living in a colony on Mars would require some significant changes to our normal social structure. Some of those changes could have moral implications depending on the moral system you ascribe to.

    1. Thanks for your compliment and your interesting comment!

      Yes, I agree with you that space colonization will have a huge impact on our social structures.

    2. So it would be important to ensure everybody has food, water, health care, shelter and clothing. This could be seen as immoral by some depending on their view.

      That’s an interesting comment – I wouldn’t have imagined that anyone could see that as immoral. Perhaps that comes from your US perspective (yes, I’ve visited your blog!).

      I’d imagine, along with both you and Mordanicus, that social and political structures would begin to change as a result of off-Earth colonisation. That’s one of the reasons I enjoy reading writers like C J Cherryh: she thinks about the evolution of societies rather than merely dropping contemporary structures into space.

  5. Mordanicus, I’m not convinced that space travel might be a solution, full or partial, to poverty, at least with our current economic and political system. I think that the poor will continue to miss out, while the rich will continue to get the cream, at least until we come up with a better system than exploitative and extractive capitalism.

    1. Alison, thanks for your comment! The current political and economical system is definitely broken and should be fixed. Poverty is a complex issue with no simple solution, which doesn’t mean it cannot be solved at all. Rather we need to implement a set of solutions. One of the measures I am strongly in favour of is the introduction of a global basic income, which would provide every person in his or her basic needs. Such project might be, among other things, be funded by the revenue generated by space mining.

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