Ashley is a UND space studies grad student. She currently works in astrophysics communication at the NASA Goddard Space Flight Center.
Since ancient times, humans’ eyes have been turned toward the heavens and filled with the wonder and curiosity of the cosmos. With giant leaps and bounds, our comprehension of the universe has grown, with a distinct focus on our own solar system. We now know that we live in a dynamic world, where not only living creatures but even vast cosmic structures like stars and galaxies are constantly evolving and taking new shape. With the use of telescopes, we can peer into the universe’s past and generate a more complete knowledge of the phases of different celestial structures. The dependence most Earth life directly has on the Sun takes on a sinister nature in this new light, as we now understand that far from being an eternal source of light and energy, the Sun will die (and indeed is already middle aged).
Fate of the Sun
As a main sequence star, the Sun will cool and expand into a red giant star as it runs out of fuel. When this occurs, it will swell until it encompasses Earth’s orbit. Life as we know it will certainly no longer be able to survive; at least not if it remains on Earth. For many decades, science fiction authors have centered novels around the idea of terraforming—a term that was devised by science fiction writer Jack Williamson, who first used it in his short story “Collision in Orbit” in 1942. Yet even before that, authors were intrigued by the idea of planetary engineering a celestial body to be habitable, and in H. G. Wells’s The War of the Worlds this process was used in reverse: Martian invaders began the process of altering Earth’s environment to be suitable for them.
The concept of terraforming may make the leap from science fiction to reality. When the Earth ventures further on the path toward becoming uninhabitable, whether from human activity or otherwise, it will become necessary for humans to leave the planet to colonize another celestial body. As there is no perfectly Earth-like candidate, the celestial body targeted for colonization will need to be altered to better suit Earth life. Currently, the best target is Mars, as private and government organizations alike intend to send humans to the red planet within just a couple of decades.
Numerous authors have penned volumes centered on the feasibility of a sustained human presence on Mars. For humans to live on Mars for very prolonged durations in comfort, the planet will ideally need to be reengineered to resemble Earth in at least a few key ways. We will need water, a breathable atmosphere, and lowered radiation levels. The wonderful thing about Mars is that it already contains the ingredients we need, and in fact only requires a moderate level of planetary warming to release and make them usable!
While there are many different terraforming technologies available at the present time, only a few will be discussed here. In his book “How We’ll Live on Mars,” science writer Stephen L. Petranek discusses a remarkably low-tech method for warming Mars: statite mirrors. He claims that “a single mirror 150 miles across could warm the south polar region of Mars by 18 degrees Fahrenheit. This would be enough of a rise in temperature to release vast quantities of carbon dioxide, a powerful greenhouse gas, into the atmosphere.” Thus the direct warming experienced by the basic raising of Mars’s albedo would be exacerbated by something of a runaway greenhouse effect, thanks to carbon dioxide’s efficacy at trapping in heat.
Petranek also suggests altering the orbit of an asteroid to make it collide with Mars. Such an act would require no spectacular technology, and yet it could warm the planet via heat created directly from the impact. In addition, it would release gases from both the planet and the asteroid itself (which could be targeted specifically for its composition), which would thicken the atmosphere and allow it to retain additional heat.
SpaceX CEO Elon Musk has taken this general concept even further, by suggesting the use of nuclear explosions (Leopold 2015). Targeted at the planet’s poles, these bombs would cause frozen carbon dioxide and water to be released into the atmosphere. Since both are powerful greenhouse gases, their release would aid in warming the planet.
The Ethical Dimension
There are a couple of key issues with such a plan, however. First, it is illegal. Article IV of the Outer Space Treaty forbids the use of nuclear weapons in space or on other celestial bodies. Even if it were allowed, the bombs would cause even more radiation—which is among the most difficult aspects of sending humans to Mars in the first place, as the planet is poorly protected from solar and cosmic radiation.
If both the legality and radiation concerns were somehow obviated, the issue of scientific contamination would remain. Article IX of the OST stipulates:
States Parties to the Treaty shall pursue studies of outer space, including the moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose.
This does not disqualify the currently planned crewed missions to Mars, but what about eventual terraforming or colonization?
Since the Earth will not be able to support human life forever, it will be imperative to choose to leave Earth. If we do not attempt to colonize another celestial body, we will contribute to the deaths of not only all humans but countless species by our failure to act.
But do terraforming and colonization constitute “harmful contamination” of the Martian environment (or any other environment we select as a target)? The introduction of plants and animals surely could qualify as contamination, if by their introduction they cause harm to something. If no life exists on the target celestial body, then introducing Earth life to it cannot be harmful.
An Anthropocentric Approach
At least that is the belief of some ethical theorists, the anthropocentrists. The anthropocentric approach proposes that humans are indeed central; we have the right to survival, and to use whatever resources that we can to our advantage. Those resources, whether they be living or nonliving, do not have rights under the hood of anthropocentrism.
Under this ethical theory, humankind could potentially live out the fear of more conservative thinkers, which is that humanity may do what we have been threatening to do for centuries and destroy our environment by over-exploitation and misuse. As a space-faring species, it would not end there—we could travel from one celestial body to another, draining each of its resources along the way and leaving a trail of desiccated planets in our wake.
Contrasting with anthropocentrism is the biocentric ethical theory, which extends rights to not just humans or higher organisms but to all living things. Every living thing has equal rights within biocentrism; no species surpasses another. This theory too would support terraforming and colonization if Earth became uninhabitable. Since we have not discovered any living things whatsoever away from Earth, biocentrists would have no qualms with altering the environments of celestial bodies as long as it served the purposes of living organisms.
Indigenous Life on Mars?
From an anthropocentric standpoint, indigenous life on Mars wouldn't be an impediment to terraforming or colonization. Humans would still be more highly valued, and so the destruction of native species habitats would be an unfortunate side effect at most. Biocentrists, however, would need to know that no life was being harmed, and would therefore rely on further study of the possibility of life existing anywhere in the Martian environment. The existence of even microbial life on a celestial body would resolutely rule out the option of terraforming efforts.
Many people would consider the possibility of harming microbial life far less concerning even than harming an ant, but a cosmic perspective changes the dynamic of the situation entirely. Had another more advanced species ventured to Earth millions of years ago when only microbial life existed and dramatically altered our environment, humans and all the other diverse forms of life now present on Earth might not have ever developed. From the point of view of the victim of terraforming and colonization, it is unacceptable. Does any species have the right to cut off the evolution and development of another species?
As of now, the discovery of life on Mars—the most probable location for terraforming efforts—seems very unlikely. If no native life is found through extensive research and exploration, the ethics of terraforming become far less complicated.
Preservation of the Cosmos (...but not humans)
A third ethical theory suggests that cosmic preservationism must be our goal. Preservationists propose that all nature is imbued with intrinsic value (whether living or nonliving) and should be protected and unaltered. Certainly colonization and global terraforming would be out of the question. This theory can pretty much be written off as unrealistic, since it would require a static universe...which we do not and will not ever live in. The cosmos is in a constant state of change, altering with every supernova explosion and galactic collision, dynamic even down to the action of the tiniest microbes and wind and sunshine! We couldn't "preserve the cosmos" even if we tried.
While such a rigid ethical framework isn't wholly realistic, there is some merit to be found here. Scientific contamination could be devastating for our understanding of planetary formation, solar system development, indigenous life, and much more. Such a drastic act as Musk's proposed detonation of nuclear weapons on the planet’s surface would destroy the opportunity to conduct many experiments and perform examinations. Even if it were legal to do it, this should be considered harmful contamination. Violent and destructive tactics should be avoided unless the alternative is even worse.
A Trail of Broken Planets in Our Wake
One concern shared among ethical theorists involves a slower, less dramatic degradation of the environments of other worlds which humans may one day journey to. If humans terraform another celestial body, will that world share the same likely fate as Earth? Realistically, if humankind reaches a point where it will be necessary for our survival to venture farther out into the cosmos and colonize another world, it will likely be because we have caused such extensive damage to our own environment that it is no longer habitable for us. If the degradation to our environment that humans now cause leads to such significant mutilation as time wears on, that will strongly suggest that the human race is not responsible enough to manage a global environment. How, then, would it be morally acceptable for humans to attempt to do so on another world? Do humans have the right to go about destroying all the planets and moons necessary until either the species dies out or no more celestial bodies are within our reach to destroy?
Worded as such, the clear answer is no. If humankind destroys the Earth environment, then it will not be ethical to continue this pattern on other worlds. Perhaps preservationists and biocentrists would agree—but certainly not anthropocentrists. The latter group would argue that we have a right, maybe even a responsibility, to preserve human lives.
Colonization and Terraforming Will Ultimately Occur
Particularly since we have discovered no other life forms away from Earth, we have a right to view Earth life as something precious and to be protected. The only relevant question is how best to go about it. The ethical theories discussed in this article will inform future policies and decisions regarding colonization and terraforming, which certainly will move forward (out of eventual necessity, if nothing else).
© 2017 Ashley Balzer