“Invaders from Earth!”: Exploring the Possibilities of Extraterrestrial Colonization
We have all seen films or heard stories about the “Invaders from Mars”: aliens coming from other galaxies to colonize Earth and take advantage of its bountiful natural resources. But what if the story happened the other way around? Organizations like the National Aeronautic and Space Administration (NASA) and private companies like SpaceX have looked seriously at the idea of space exploration for colonization, particularly when it comes to the possibility of colonizing artificial satellites, the Moon, or even our planetary neighbor Mars. With worries about the decline of Earth’s habitability in the not-too-distant future – due to environmental degradation, lack of resources, and climate change – individuals and institutions are exploring the modern frontiers of space technology that could soon transform humankind into the “Invaders from Earth.”
From Science Fiction to Science Reality
Extraterrestrial colonization seems like a concept straight out of a sci-fi movie – Christopher Nolan’s 2014 science fiction drama Interstellar features protagonist Matthew McConaughey trying to find a new home for mankind as food shortages and crop failures threaten society’s existence on Earth. Surprisingly though, the idea of space colonization has been around for quite some time now. In 1869, The Atlantic Monthly published a short story by Edward Everett Hale entitled “The Brick Moon,” in which an artificial satellite accidentally gets launched into space with people still inside of it, leading to the establishment of the first space colony (1). The idea of a “space colony” eventually took shape in 1971 in the form of the Russian Salyut program, resulting in the first crewed space station in history.
In the mid to late-1970s, not long after the United States put astronauts on the Moon in the famous Apollo missions, scientists and engineers began to seriously consider the idea of extraterrestrial colonies living in artificial space habitats just outside of Earth. One of the first, and indeed one of the most influential, scientific papers on the topic was “The Colonization of Space” by Dr. Gerard K. O’Neill of Princeton University, which was published in the popular magazine Physics Today in 1974 (2). Through careful calculations and consideration of the physics and economics behind the construction of a space habitat, Dr. O’Neill concluded that mankind could “build pleasant, self-sufficient dwelling places in space within the next two decades, solving many of Earth’s problems.” As a result of this study, the NASA Ames Research Center began to conduct space settlement studies to support the NASA Ames Space Settlement Contest, a space colony design contest for primary and secondary school students (3). The study begins with the following thought-provoking questions: “We have put men on the Moon. Can people live in space? Can permanent communities be built and inhabited off the Earth?” So commenced NASA’s formal research into the idea of sustaining human civilization outside of our planet.
Searching for a New Home
Why would it even be necessary to have mankind live in colonies outside of Earth? Perhaps the most compelling reason to explore the possibility of extraterrestrial colonization has to do with our own environment. As the Earth’s population continues to grow – it is expected to balloon to over 11 billion by 2100 – and as resources like freshwater and food become more scarce, many people fear our planet will become far less capable of sustaining human life. Famed scientist Stephen Hawking has even delivered a lecture titled “Why We Should Go Into Space,” urging society to continue space exploration to ensure humanity’s survival (4). As Dr. Hawking states in one of his lectures on space colonization, “if the human race is to continue for another million years, we will have to boldly go where no one has gone before.”
Climate change is also threatening to make Earth much less hospitable in the future. Average land and sea surface temperatures are increasing, sea levels around the globe are rising, atmospheric carbon dioxide levels have reached all time highs, and precipitation patterns are shifting (5). In the long term, these changes could lead to detrimental effects on human health, crop production, species extinction, and other major environmental catastrophes. On top of this, the risk of nuclear war leaving Earth inhospitable or the threat of a major asteroid leading us to the same fate as the dinosaurs are other reasons why advocates of extraterrestrial colonization suggest that we, as a society, should start looking at a Plan(et) B.
Modern Frontiers in Space Colonization
Colonizing other Planets
American company SpaceX (short for Space Exploration Technologies Corporation), led by business mogul Elon Musk, was founded in 2002 with the primary end goal of enabling the human colonization of Mars (6). By designing, manufacturing, and launching space transportation products, SpaceX has become one of the modern leaders in spaceflight. Since its founding, SpaceX has been the first private company to successfully launch and return a spacecraft from low-Earth orbit, as well as the first company to send a spacecraft to the International Space Station. This is changing the way society has traditionally engaged in space exploration, moving the business of space travel from government agencies to private industries. With these developments in space technology occurring within the private sector, the possibility of sending humans to other planets is one step closer to becoming a reality.
Other companies, like the Mars One Corporation, are joining in on the quest to tackle the Mars problem as well. With the goal of establishing a “permanent human settlement on Mars,” Mars One is seeking capital investment, manufacturing partners, scientific advisers, and other critical partnerships that could make the settlement of Mars a reality within the 21st century (7).
The Radical Idea of Terraforming
In the curious world of extraterrestrial colonization, there is another conceptual framework for colonizing planetary bodies that involves a complete transformation of entire planets: terraforming. Terraforming a planet would require significant human engineering and manual alteration of environmental conditions: modifying a planet’s climate, ensuring an atmosphere with sufficient oxygen, altering rugged landscapes, and promoting vegetation and natural biological growth. Scientists have deliberated the idea of making a planet like Mars habitable to human life through various transformations of the environment on a planetary scale. One possible scenario would be to introduce greenhouse gases into the atmosphere of Mars, leading to steady increases in surface temperatures – an induced greenhouse - that would perhaps make the planet hospitable to plants within a time period of 100 to 10,000 years (8). The next step would involve carbon sequestration and the introduction of plant life. Vegetation on Mars would lead to the photosynthetic conversion of CO2 into O2, eventually rendering the Martian atmosphere “human-breathable.” Humans would also have to address the problem of ultraviolet radiation shielding (since the Martian atmosphere is so thin), maintaining a warm air temperature, and a myriad of other complications in order to sustain a human-compatible Martian environment (8). While NASA scientist James Pollack and legendary astrophysicist Carl Sagan thought it was within the realm of human capabilities to engineer other planets, they strongly believed the “first step in engineering the solar system is to guarantee the habitability of the Earth” (9). In other words, science must first commit itself to the conservation of this planet before attempting to alter or flee to another.
So what’s holding us back from actually getting to Mars and starting a colony? One big reason is the sheer cost of such an operation. In 1989, President George H.W. Bush introduced the NASA Space Exploration Initiative, which would have culminated in sending humans to Mars (after landing astronauts on the Moon again). This initiative was immediately shut down due to concerns over the costs: over $500 billion (10). Mars Direct, a plan created by the Mars Society to colonize the Red Planet through a “minimalist, live-off-the-land approach to space exploration,” is estimated to come at a cost of about $30 billion (11). While this is substantially less than what a NASA mission to Mars would cost, it is still a significant sum that requires huge investment and careful consideration of the costs and benefits of a project of this scale. A mission to Mars would also take years of planning and budget allocations, especially if it were to go through a public science agency like NASA. The NASA Apollo missions were initiated in 1961 in the form of unmanned spacecraft and preliminary manned Earth-orbit missions before astronauts finally landed on the Moon in 1969. A mission to Mars, which would take longer and is much more technologically challenging, would require similar planning efforts.
Recent breakthroughs in space exploration technology, both in the private and public sectors, are making the possibility of extraterrestrial colonization much more realistic. Space colonization is no longer merely the plot of a hit sci-fi flick, as entire corporations are investing millions of dollars into the technologies and engineering advancements that will make reaching Mars possible before the end of the century. Pretty soon, instead of looking up at the night sky from Earth, perhaps we will be looking up from Mars and staring at the blue dot that we used to call “home.”
 Hale, E. E. Atlantic Monthly 1869, 24.
 O’Neill, G.K. Physics Today, 1974, 27.9, 32-40.
 Johnson, R.; Holbrow, C. Space Settlements: A Design Study. NASA. 1977.
 Hawking, S. Why We Should Go into Space; NASA’s 50th Anniversary Lecture Series, 2008.
 NASA. Global Climate Change. climate.nasa.gov
 SpaceX. spacex.com
 Mars One. mars-one.com
 McKay, C.P. et al. Nature 1991 352, 489-496.
 Pollack, J.B.; Sagan, C. Arizona Univ., Resources of Near-Earth Space. 1991 921-950.
 NASA. Summary of Space Exploration Initiative. history.nasa.gov
 The Mars Society. marssociety.org