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Markkula Center for Applied Ethics

Remarks by Brian Green

Brian Green

Brian Green

Brian Green

General Ethical Considerations with Space Exploration and Use

  • Should humans go forth into space?
  • When we think of going into space, what is attracting us?
  • Or is there something on Earth which is “pushing” us away?
  • When we go into space, what are we looking for?
  • Ultimately, I think we are looking for ourselves, who we are; a deep metaphysical and moral question.

Arguments for Going into Space

Arguments in favor of going into space include such basics as gaining scientific knowledge and developing beneficial new technologies, both of which space exploration and use have accomplished with unexpected and dramatic effect for humankind.

Scientific advancements include astronomical and cosmological knowledge from various orbiting experiments and telescopes as well as a great deal of scientific knowledge about Earth, including measurements of environmental status, habitat conversion and destruction, detailed knowledge of anthropogenic climate change, and much about Earth’s chemistry and geophysics.

We have also learned a great deal about our local planets. For example, a runaway “greenhouse effect” makes the surface of Venus uninhabitable, while lack of greenhouse effect on Mars leaves the surface quite cold.

On the technological side, so much technology has been pioneered through space exploration and use that it is hard to make a comprehensive list, but some of the more important technologies include weather satellites, GPS, communication satellites, solar photovoltaic panels, advances in electronics and computers, and advances in materials science.  

Space is also a key way of promoting international cooperation and global awareness.

While the international competition known as the “space race” fueled the USA all the way to the Moon, shortly afterward, the Apollo-Soyuz program began an era of greater cooperation in space.  Currently the International Space Station continues this cross-national cooperation.

In addition to cooperation in space exploration itself, the perspective given from space and  the famous “Blue Marble” and “Earthrise” pictures have provided an image of unity on Earth.  

Scientific discoveries supported by space science, such as climate change, have led to international cooperation to address these problems.

Gaining access to new sources of critical resources may be another reason to go into space.

Earth is a finite planet, and certain elements on Earth are very rare in the planetary crust.  However, asteroids and other objects in space  sometimes contain these elements in abundance..

In addition to returning elements to Earth, further exploration and development of space will require access to resources which are not purely sourced from Earth, such as water.

Another reason that humans may want to explore space would be to create a “back-up Earth” to hedge against global catastrophe and/or human extinction on our home planet.

I think this is a more serious problem than most people realize. Earth has always been a dangerous place for humans, with natural threats including asteroid impacts, volcanic eruptions (volcanic winter or otherwise massive eruption), and pandemic disease.

None of these are jokes. They are serious, difficult to deal with, and not as improbable as we might like. But now, human-made hazards join this list too, just to make things more difficult:

  • nuclear war and winter
  • environmental degradation / toxicity
  • anthropogenic climate change
  • ocean acidification / anoxia
  • biotechnology / synthetic biology / bioweapons
  • nanotechnology
  • artificial intelligence
  • geoengineering / climate engineering…

A serious, global-scale catastrophe could set back civilization many decades or centuries. The worst disasters could even cause human extinction.

If 100% of humanity died in a disaster, all  human effort throughout history could be for nothing.

However, if humans had just one self-sustaining settlement off-Earth, the same global catastrophe would not result in the end of human civilization.

Instead, while the same horrible fate would befall the Earth (certainly no mere triviality, with perhaps the deaths of 99.99% of all humans), at least all  human accomplishment would not be for nothing.

The philosopher Hans Jonas argued, against Immanuel Kant, that there is really only one categorical imperative in moral philosophy, and that is that humankind must exist. Why? Because without people there is no morality: we are the foothold of morality in the universe. Therefore, if we are to act morally, we must first exist.  This fundamental assumption of philosophy only came into question when humans gained the ability to conceive of our own extinction, due to the tremendous destructive power of technology.

I think Jonas is right, and that this imperative is the highest moral principle: humanity ought to continue to exist. Therefore we need to take steps to ensure our continued existence, including having back-up civilizations off of the Earth. Reducing risks on Earth is also absolutely vital, but despite human efforts to  do so for decades, the risks are actually getting worse.

Stephen Hawking, Elon Musk, Nick Bostrom, and others have been pointing at catastrophic and existential risks for quite a while, and I really do think that they have found a justifiable and immediate concern.

The Fermi Paradox, famously wonders “Where are they?” about ETIs, and no satisfying answer has been found. If life is easy to evolve, then intelligent species ought to be abundant, we might think… yet we see none.  Are they all dead? One question to ask though is, “Does the ‘filter’ that eliminates ETIs lie ahead of us or behind us?” If it is ahead of us, then we need to become multi-planetary as soon as possible, because something bad may await us soon.

Another consideration is that we may not always have access to space, so speed is important.

The Kessler syndrome (growth of orbital debris) or other setbacks may block our access to space, or other disasters may degrade humanity’s ability to engage with space. Now may be the time within a limited window of opportunity.

There is no necessary reason to assume that the inaccessibility of space may not return in time, either due to natural or human events.

As a last reason to go into space, many people find inspiring the personal experience and the sharing of personal experiences and stories of exploration. This is the call of ADVENTURE and PURPOSE.

Only 12 humans have ever walked on the Moon, but those few men, while greatly inspired themselves, also inspired countless other people around the world.

I have talked to individuals who, despite their material poverty, felt deeply connected with the idea of space exploration. It truly is an inspiring human endeavor.

We should not underestimate the importance of wonder and amazement in human life. Providing wonder and purpose are all worthy goals; they are not insignificant.

In a world where traditional meanings such as those described by religion, nation, ideology, tribe, family, worldview, and other identities are becoming weaker, purposelessness is becoming an increasingly common problem. With a lack of good outlets for this teleological and tribal impulse, pathological forms erupt forth, such as drug-abuse, crime, terrorism, and other anti-social behaviors.

With the existential turn in some philosophies and cultures, questioning our goal, purpose, and meaning in life has become a genuine task in many people’s lives, not only for themselves, but for all of humankind.

Arguments Against Going into Space

There are, of course, also strong arguments against going into space.

First, space exploration is extremely costly.

Currently, the cost of getting into space is thousands of dollars per pound.

Surely, anything in space ought to be worth it… so with such high costs, are such seemingly frivolous activities like settling the Moon or Mars worth it?

The cost problem manifests not only in the direct expense of spending the money on projects with specific and limited benefits, but also in what is not funded.

When money is spent on space, it is not spent elsewhere. There are countless pressing problems here on Earth which would seem to be a better use of our limited resources.

Surely the requirements of justice and equality would indicate that these resources would be better spent helping the poor gain access to the basic necessities of life, like healthy food, clean water, sanitation, education, healthcare, decent jobs, safety and security.

And yet, in practice, monies subtracted from space do not instead go directly to the poor (though perhaps they ought to).

In its favor for helping the poor, space exploration is a form of research and development, and as such, it is an investment in the future: we incur present costs in the hope of future rewards. Without R&D over history, we would not have the abundance that we live in now.

Interestingly, one spin-off technology promoted by space exploration, solar photovoltaic (PV) cells, are becoming quite helpful for providing electrical power to poor and remote people here on Earth. 

So while the R&D put into PV cells over the last few decades could no doubt have immediately helped many people in the past, without that research, people would not be benefitting from PV cells today.

The tradeoffs between immediate needs and future needs are difficult to weigh, and can be a genuine source of ethical debate.

However, concern for the present should not completely shut-down R&D for the future, because we know that, given our present technology (rooted in fossil fuels and other environmentally destructive practices), we cannot continue to survive sustainably on the planet without dramatic technological progress.

As a second reason, space exploration is a risky endeavor, and people have died and will continue to die as exploration proceeds.

There is no way to make space exploration 100% safe. There will always be a risk of something going wrong, though there are certainly ways to make things safer.

Yet, of course life on Earth is also risky. We could be hit by a car or die of cancer, and certainly someday we will all die.

Risk is not absolute, but can only be relative; for example, air travel is safer than walking.

But space exploration is not yet a “safe” activity, and it may never be so, due to the enormous energies and speeds involved, not to mention the effects of radiation, microgravity, lack of access to basic human health needs, reliance on artificially met needs (e.g., atmosphere, food, and water), and so on. Yet many people still want to go.

Third, we cannot completely discount the possibility that in our explorations we may discover or unleash dangerous things that we would be better off not knowing about.

Other planets may naturally harbor microbes or other organisms capable of injuring or killing humans or other Earth life forms.

If this is the case, contamination and decontamination become foremost concerns in space exploration – however, they must be concerns before contact is made, otherwise it may be too late.

Planetary protection currently operates with stringent guidelines for preventing forward and backward contamination from space, but the more space activity there is, the more difficult it becomes to monitor and enforce.

Additionally, space exploration technologies are intrinsically powerful and dangerous, and  will need to be regulated by agreed upon laws and enforcement, otherwise we risk all sorts of bad stuff, up to and including war between human groups in space. That is ignoring any possible ETI dangers, which are so unknowable there just isn’t much to say.

Now to Mars, Specifically

Both the public and private sector are interested in conducting human missions to Mars. Elon Musk’s SpaceX has their explicit corporate goal as the creation of a self-sustaining colony on Mars. The US government talks on and off about sending humans to Mars, but has been delaying on that goal for decades.

Should Mars exploration be a “Wild West” where anything goes, or should there be limitations on what people can do, and if so, how should these limits be determined? I think it is very obvious that the “anything goes” strategy is not a good one. We need an orderly approach to the future of human exploration and settlement of space, but not so orderly that it dies mummified in red tape. I think this is a pressing goal, one which deserves much more attention than it is currently getting, but it also really needs to be done right, not haphazardly, or there are genuine threats.

Humans should settle Mars. The positives and negative are like those stated above, but with a few more precise considerations, especially as pertaining to the possibility of life. But we need to remember that native life is an unknown on Mars. It may not exist at all, in which case our caution would be unwarranted. We need to balance protecting hypothetical Mars life from contamination with the fact that we know humankind exists and we know we are exposed to serious existential risks.

Will a human presence on Mars forever damage the native Martian ecosystem (if there is any) by releasing invasive Earth microbes? Maybe… “Damage” or just “change” – the words are important and the probable results unknowable. It would be best if we could avoid risking damage to any potential native life forms on Mars. However, I don’t think humanity can thoroughly search the planet for life in any short amount of time, and searching for life might best be done by a settlement of humans in any case. Settlement means contamination. There’s almost no way out of it.  Humans are too dirty with microbes, and we need to be that way. Those microbes most likely will die on the Martian surface, but we still cannot be certain.

Should we terraform Mars to make it more like Earth? Maybe… But rushing into terraforming might be a dumb idea. At the start, paraterraforming, or tent-terraforming would be  more economical, safer for the planet, more reversible (should something go wrong), and less grandiose/hubristic – let’s not invite disaster as the very first thing we do!

If there is no life on Mars, does that mean we can do whatever we want  with the planet? No. The planet deserves respect as it is, even without life. The root of this respect might be either in its intrinsic value, or it could be in our own human value, that we would not want to be those sorts of people who would wantonly destroy and wreck places, but in any case, the result is the same. We should try to do better on Mars than we have done with Earth.

Respecting Mars does not necessarily mean leaving it alone, however. Spreading life there, if done the right way, might be the best way to “respect” Mars, by helping it attain its full potential as a life-bearing planet.

If there is native Mars life, should we “leave the planet to the Martians”? No. I hope that Mars life and Earth life might be able to coexist. But even if there were native Mars life, it might be underground or limited in such ways that escaped Earth microbes would have trouble encountering it. The contamination of humans by Martian microbes is another matter, but hopefully the hypothetical Martian microbes simply won’t be able to harm humans or our associated necessary life-forms. In any case, before anyone returns to Earth from Mars they will need to undergo thorough tests and quarantine.

If there are native microbes should we try to “help” them by making Mars more hospitable to life? Yes. Mars is a dying planet. It is not going to get better for life until the Sun is approaching the end of its life, which will be too late. “Helping” might seem a strange idea in this context, but I think we can make helpful assumptions about what could benefit Mars life. Warming the planet and freeing up liquid water both ought to “help” Martian life.

So, Should We Go?

I conclude that space settlement will be beneficial, even despite its relative expense and dangers.

The foremost benefit of space settlement is that it makes possible “back-ups” of humanity, should disaster befall the Earth.

Currently humanity’s eggs are literally all in one basket (you know the saying: don’t keep your gametes all on one planet!), and as technological dangers grow, it behooves us to not only pursue technologies to increase safety and security on Earth, but also to create the ultimate insurance policy against disaster, in the form of off-planet settlements. 

This is certainly not only a depressing task like paying insurance: how many people ever exclaim “Yippee! Insurance!” It’s also one of the most inspirational tasks that humanity as a whole can embark upon at this point in history.

Space exploration can provide a new outlet for human ambition, identity, and purpose, one which is creative and not destructive, as well as potentially  compatible with many of the older wisdom traditions. 

Carl Sagan used to say humans are made of “star stuff.” Science has shown us that; that is our past. Perhaps returning to the stars is also our future.

Thank you.


Feb 19, 2016
All About Ethics