ABSTRACT
Microbial and mechanical contamination of other planets is an ethical risk versus reward battle that the National Aeronautics and Space Administration (NASA) grapples with each mission. Humankind strives to explore and discover, but potentially at the expense of ecosystems apart from our own. Humanity must evaluate the consequences of planetary contamination, as we are the only known species with access to the external universe. There is an imminent responsibility to preserve and protect outer worlds and be noble in our quest in conquering the final frontier.
According to a Huffington Post survey, nearly 47% of Americans believe in aliens [1]. To justify this belief in extraterrestrial life, we have blurry photographs taken on 20th century digital cameras. Needless to say, it’s no iPhone X, and probably not an alien either.
Perhaps compelled by our search for extraterrestrials, humanity’s strides in understanding outer space are quite literally out of this world. Science and engineering propel innovation, demanding the answer to one astronomical question: does life exist outside Earth?
In the search for an answer, the National Aeronautics and Space Administration (NASA) establishes interplanetary contamination as a major obstacle in identifying harbored life on other planets [2]. As contact with extraterrestrial ecosystems increases, so does the potential for destroying a world beyond our own [3]. Evaluating the ethical consequences of planetary contamination is essential in the push toward the final frontier– we must acknowledge our own biological threats to protect and preserve the cosmos from humanmade repercussions.
NASA defines interplanetary contamination in two components: forward and backward contamination [2]. Forward contamination refers to the deliberate or accidental biological contamination of a celestial body by human made spacecraft, while the latter describes the contagion of Earth by external bodies. Either would result in the unnatural deposition of foreign microbes in a new environment, shifting the ecosystem, food chain, and organic order of the universe [4]. According to Madhan Tirumalai, a post-doctoral biologist at the University of Houston, “The task to eliminate microbes in clean rooms, where spacecraft are assembled, or aboard spacecraft, will continue to be a challenge for NASA and other space agencies” [5]. NASA spotlights forward contamination as their primary concern because human ethics are unrelated to the natural phenomena that cause backward contamination.
From the smallest fleck of satellite paint to the 400,000 pounds of American machinery left on the moon, humankind has already left a clear cosmic footprint. There are at least 21,000 pieces of human made debris orbiting Earth and a 2.5 billion dollar cart idling on the surface of Mars [3]. With machinery come microbes, and infecting another planet with terrestrial life poses an incalculable threat to the planet’s ecosystem [6]. The consequences of this behavior lie in the eye of the beholder, because we must assign value to the extra worldly environment and its life. To evaluate the risks of space exploration, humanity must question the legal, ethical, and social aspects of planetary contamination [7].
The federal government strictly regulates space exploration. The first attempt to control space operations– the United Nations’ Outer Space Treaty of 1966– asserts, “States shall avoid harmful contamination of space and celestial bodies” and “shall be liable for damage caused by their space objects” [8]. In response, NASA implemented the Planetary Protection Policy in 1967, stating, “The Earth must be protected from the potential hazard posed by extraterrestrial matter carried by a spacecraft returning from another planet or other extraterrestrial sources” [2].
By law, if a planet harbors life or evidence thereof, contact with the environment is out of the question for fear of microbial contamination. The policy, however, fails to consider cosmic bodies that lack the potential to support living organisms. As children, we are taught to leave places as good as or better than we found them, and the same reasoning should apply to outer space. Legal standards are based on our valuation of life-lacking environments. Therefore, the Space Administration must redefine what constitutes harm and endangerment to include any activity that tarnishes an environment.
The intrinsic beauty of other worlds should equate in value to that of Earth. In essence, humankind should hold the canyons, mountains and oceans of a moon millions of light-years away in equal esteem to the terrestrial counterparts. The destruction of nature on Earth is looked down upon; that same concern should apply everywhere. According to NASA, “when we make the decision to protect a place from our mission leftovers, it highlights what we consider to be worth preserving” [4]. Astronauts cannot board their space vessel and collect unwanted refuse floating in the blackness of the solar system, so we must take precautions to preserve these environments for the good of all beings, even if these beings have not yet been discovered. Thus, the space administration currently battles the risk versus reward of space exploration, aiming to minimize the risk at all costs, both ethical and fiscal [3]. Humans are instinctive explorers, but it is critical that the lessons learned from previous experiences with mechanical contamination carry over to future missions, ensuring the wellbeing of planetary environments and their potential to harbor life.
Planetary contamination is often evaluated from the perspective of future generations. The “space junk” orbiting Earth and the remains of technologies left on cosmic bodies will serve as a monument to human innovation and achievement. Similar to how the current generations attach sentiment to Civil War cannons, the first computer, or ancient architecture, the remnants of early space development highlight historical defiance of the impossible [3]. One must also consider the resources other planets could offer to posterity; for example, Earth’s oil supplies are running dry due to considerable demand and the expendability of this fixed resource, and some scientists believe that the solution lies in the crust of neighboring planets. Though it seems like science fiction, humans could soon be inhabiting and exploiting other cosmic bodies for fiscal gain. In this case, jeopardizing an extra-terrestrial ecosystem could benefit life on Earth; however, the ethical cost of desecrating universal order outweighs the economic and social benefits of this behavior. Wealth is a uniquely human desire. We share the universe with innumerable other species whose existence should be respected and left uncompromised.
NASA actively takes steps to curb planetary contamination while continuing to push toward the final frontier. NASA “strives to reach for new heights and reveal the unknown… by both protecting our own precious home and the undiscovered country [humanity is] now pioneering” [9].
The Europa Clipper Mission of 2022 embodies these efforts. Europa, one of Jupiter’s moons, is home to a liquid water ocean twice the volume of Earth’s oceans. Water can signify the presence of life, so the preservation and protection of a cosmic body has never been of greater importance. Rather than landing spacecraft on the surface of this moon (and evaporating due to the extreme radioactivity), Clipper will conduct 45 flybys over Europa, gathering data via sensors and radar and completely avoiding direct contact with the ocean and, potentially, living organisms [10].
In the Psyche Mission of 2022, the Psyche spacecraft will orbit a large asteroid between Mars and Jupiter. Radar sensors and neutron spectrometers will characterize its topography and determine its composition, thought to be similar to Earth’s core [11]. NASA will conduct all tests without breaching the surface of the asteroid or leaving anything behind. The Space Administration aims to minimize direct contact between Earth and the cosmos, as to end the deposition of terrestrial objects on other bodies; they continue to set a precedent for private space companies and emphasize the need for technological advancements that minimize the contamination of other worlds.
Humans are the protectors of life and the universe. Humans are the only ones with the capability to empathize with living organisms, control their fate, and dictate the destiny of the natural world. Humankind has the inherent responsibility to evaluate the importance of life and the millions of other worlds surrounding us [7]. We must be noble in space expeditions, leaving no trace of activity out of respect for creation. We must be cognizant of the power we hold; if a planet were to be infected with terrestrial microbes, its history would divide into two categories: the world before Earth life and the world after. We must be humble in our quest to discover, recognizing our own trivial role in the evolution of the universe and our insignificance in the macrocosm. Humans hold no authority to disrupt the natural order of the universe and jeopardize what should be held sacred. Exploration, discovery, and knowledge are the foundations upon which humankind proudly stands, and should continue to develop, but not at the expense of the cosmos. NASA and other privately funded space administrations must recognize the grave errors of the past involving the literal and metaphorical footprints left in outer space. They must strive to both correct past behavior and prevent future contamination incidents before another planet is unintentionally populated with Earth’s biology.
By Ashlynn Smith, Viterbi School of Engineering, University of Southern California
ABOUT THE AUTHOR
At the time of writing this paper, Ashlynn Smith was an undergraduate chemical engineering student at the University of Southern California. She hopes one day to design spacecraft and propulsion materials for the American Space Administration.
REFERENCES
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