ambitious plan ethically justifiable? Yes. McKay starts with a simple axiom: life is better than non-life. If life is better than non-life, says McKay, then it would be our moral responsibility to sponsor ecosynthesis on that planet. Transferring terrestrial life forms to Mars would be better than leaving Mars lifeless.
Curiously, McKay appeals to both intrinsic value and instrumental or utilitarian value when justifying planetary ecosynthesis. First, the intrinsic argument. Because life has intrinsic value, Mars with life would be ethically of greater worth than a lifeless Mars, even if it is transplanted life. Second, the instrumental argument. Because we on Earth would learn so much from the Mars project about sustaining a biosphere, we could apply what we learn on Mars to sustaining Earth’s biosphere in the face of our imminent ecological challenges. “Both utilitarian and intrinsic worth arguments support the notion of planetary ecosynthesis” [2.46].
Should we terraform Mars or any other celestial body within our solar neighborhood? On the one hand, McKay’s argument that life is better than non-life provides a sound point of departure. On the other hand, transplanting terrestrial life to an extraterrestrial location looks a great deal like colonizing. As we bring the history of terrestrial colonization to mind, we cannot avoid recalling the imperialism and greed that motivated colonization and the devastating impact of exploitation and genocide on the lands colonized. The Crysdale incorporation of risk based upon what we know from history about human nature gives one pause.
Our pause cannot last too long. The Mars Society is already making plans to colonize the red planet.
2.3.9 Should We Establish Human Settlements on Mars?
Should we earthlings become a transplanetary species? Should we begin establishing human settlements on Mars? [2.44].
Colonize Mars? Yes, says Robert Zubrin, director of the Mars Society, because it’s our destiny. “Mars can and should be settled with Earth émigrés” [2.96]. No, cautions NASA consultant Linda Billings, because colonization would exacerbate terrestrial inequality. “It would be unethical to contaminate a potentially habitable planet for further scientific exploration and immoral to transport a tiny, non-representative, subset of humanity—made up of people who could afford to spend hundreds of thousands to millions of dollars on the trip—to live on Mars” [2.8]. Stealing resources from the lower classes to send the wealthier classes to Mars would violate the principles of distributive justice.
Some critics argue that, because we humans have messed up Earth, it would be immoral to do the same to Mars. Adler Planetarium astronomer Grace Wolf-Chase admonishes us to clean up Earth’s mess before we mess up another planet. “Considering the possibility of extraterrestrial species motivates us to re-evaluate humanity’s history as stewards of Earth, and to examine critically human behaviors before migrating to other worlds” [2.93].
Would colonization be legal? The UN Outer Space Treaty, recall, holds that Mars, like other celestial locations, cannot be subject to national appropriation by claim of sovereignty, by means of use or occupation. Might the USA or China—whichever country lands first—simply stake a claim? “I don’t see how Mars could be anything but a land grab driven by homesteading rules,” pines Christopher Wanjek [2.91].
Among the many quandaries that the prospect of colonization raises is this: will earthlings living on Mars still be earthlings? Or, will evolution require such a level of adaptation that humans will become posthuman? Polish scientist Konrad Szocik along with his colleagues entertains this quandary and responds by recommending CRISPR gene editing to enhance adaptation. “It is worth keeping in mind that living in different—let’s call them unnatural places, which are not a part of the environment of evolutionary adaptedness—locations is not problematic per se, if humans are prepared in an appropriate way to live there” [2.82]. Astroethicists of responsibility must engage the question: Is it our moral right if not obligation to engineer the future of human evolution so that a successor species—a posthuman species—emerges?
Here is my tentative response: if a biosphere exists on Mars, then we should treat it as having intrinsic value. But if Mars is currently lifeless then, despite the interplanetary necessity for genetic engineering, we should take advantage of the opportunity to seed the Red Planet with life for the sake of its future. This becomes the moral warrant for both terraforming and colonization.
What about the mega vision of extending the habitat of Homo sapiens to outer space, turning earthlings into a transplanetary species? I applaud such a grand vision. I only add two grumbles, one scientific and the other theological. Scientifically, once Earth’s colonists have adapted to a significantly new off-Earth environment, their descendants may no longer be human. We will not be able to say confidently that a single transplanetary species has come into existence. Theologically, we ought not to expect a utopian life to commence on a new planet. We ought not to expect we will create El Dorado or a heaven in the heavens. Earth’s colonists to new worlds will bring with them a very ancient yet perduring pattern of living: sin.
2.3.10 How Do We Protect Earth from the Sky?
Even with colonists migrating from the third to the fourth planet, the vast majority of earthlings will remain living on Earth. Earth will continue to be our home for the foreseeable future. The ecological-ethical mandate is clear: if we Homo sapiens do not get our act together we’ll go extinct before Martian microbes will.
Earth is a dangerous place to live. The heavens threaten. The Sun occasionally launches solar flares, which fry electricity grids by generating intense currents in wires. More rare than solar flares but equally potent are blasts of radiation from a nearby γ-ray (gamma ray) burst. A short-hard γ-ray burst, caused by the violent merger of two black holes or two neutron stars or a combination, provides the most frightening scenario. If one such blast would be directed at Earth from within 200 parsecs away (less than 1% of the distance across the Milky Way), it would zap Earth with enough high-energy photons to wipe out 30% of the atmosphere’s protective ozone layer for nearly a decade.
There are more threats coming from Earth’s heavens. Comets and asteroids, when large in size, can explode on Earth’s surface with the impact of a nuclear bomb. It is widely believed among scientists that sixty-five million years ago an asteroid ten kilometers in diameter hit Earth and triggered the mass extinction of dinosaurs. Can we protect Earth from future asteroid catastrophes? The UN’s Science and Technical Subcommittee’s Near-Earth Object Working Group and its internal panel, Action Team 14, have been working on the details of an international approach since 2001.
The astroethical response to possible and probable futures is to prepare. These damage scenarios lead us to think ahead. We need to plan for our planet’s future, and we need to incorporate such possibilities into our planning. With regard to solar flares, fortunately, there are ways to mitigate the damage should it occur: engineers can protect the grid with fail-safes or by turning off the power in the face of an incoming blast. With regard to a comet or asteroid strike, we will be given advanced notice. A diversion strategy could be effective, perhaps by hitting the object while it is yet far away with a nuclear bomb. We have no way to prevent gamma ray bursts from striking our Earth, but we could provide protective shields in sanctuaries for life forms we wish to restart following the event. These matters belong to our quandary. Just how will we respond?
2.4 Levels of Intelligence in the Milky Way Metropolis
Is it likely that yet-to-become neighbors are already living in our Milky Way metropolis? Yes, indeed. “A conservative estimate,” speculates University of Arizona astrobiologist Chris Impey, “might be a billion habitable ‘spots’— terrestrial planets in conventionally defined habitable zones, plus moons of giant planet harboring liquid water—in the Milky Way alone. That number must be multiplied by 1011 for the number of ‘petri dishes’ in the observable cosmos” [2.34].
When we meet them, will they be like us? No, says philosopher of biology Michael Ruse. Something like us, perhaps; but not us. “It seems that natural selection can and does produce intelligent beings all the way up to humans.