The Earth, as of October 2019, provides the resources required for life for just over 7.7 billion human beings. Modern humanity did not evolve until recently, which was just about 200,000 years ago. Yet, humanity has managed to populate the earth heavily in such a small span of time. Due to humanity’s large population, the sustainable resources of the Earth have been declining at a rate that cannot be replenish. Even with the technological advances of today, humanity is still a large contributor to the depletion of earth’s resources.
Humanity has done, and is still currently doing, everything within their power to reduce or even prevent the depletion of the Earth’s remaining resources. However, the solution to humanity’s dilemma may not be found here on Earth. Perhaps humanity should look past the boundaries of Earth’s atmosphere and find the solution in the vastness of space. Perhaps it may be time for humanity to find a new home, a “Second Earth”.
With space being so vast, it is highly possible that there is a planet with a similar makeup to our very own. Although the vastness of space increases the probability that a planet with a similar makeup to Earth exists, the vastness of space provides us with another problem. Even if humanity were to find another Earth-like planet, humanity lacks the technology capable of travelling such extreme distances. However, what if humanity did not have to travel extreme distances to find a “Second Earth”? Humanity, instead of searching for such a planet, could possibly re-create Earth within our own Solar System utilizing a concept known as terraformation.
The terraforming of planets is defined as the act of changing the overall environment of the planet so that it is better suitable for lifeforms of Earth origin. The concept of terraforming first appeared in the science-fiction novels of author Jack Williamson in the 1940s and in 1981 the concept was further expanded upon in a non-fiction book by James Oberg (Vasileva et al., 2019). This concept was thought to be nothing more than science fiction, at least until very recently. Just as humanity evolved from our primitive ancestors, technology has been evolving and improving at a similarly extreme rate. While humanity still lacks the technology to travel to a “Second Earth”, humanity may have the technologies required to create such a planet utilizing the concept of terraformation.
When discussing the topic of terraformation of a planet, Vasileva et al. (2019) found that discussions tended to focus on two key questions: “Should we?” and “Can we?”. The first question, “Should we?”, refers to the ethics of terraformation of a planet, and whether it is right for humanity to deliberately destroy a pristine planet for the benefit of humanity. The second question, “Can we?”, simply asks whether if humanity can realistically create a “Second Earth” using the concept of terraformation. Before focusing on the ethics of completely terraforming a planet, whether it be a planet within our Solar System or a planet elsewhere within the known universe, humanity should first seek to see if it is reasonably possible to perform planetary terraformation.
In order to determine whether humanity can create a “Second Earth” a candidate from a planet within our solar system must be chosen. Planets within our solar system, except for Earth, are uninhabitable to humans and other organic life originating from Earth. Without the assistance and protection of spacecraft or spacesuits at the very least. So there really isn’t a planet within our solar system that is a clear candidate for terraformation. However, there are other factors that can help determine which planet would be an optimal candidate for terraformation. One such factor is the sidereal rotation period of a planet.
The sidereal rotation period of a planet is a factor that can help us determine which planets are eligible candidates for terraformation. Essentially, the sidereal rotation period (or “sidereal day”) gives us the length of what humanity perceives as a day on a planet. For example, the sidereal rotation period of Earth is 23.93472 hours, or about 24 hours as it is commonly observed to be. Ideally, the candidate for planetary terraformation would have to have a sidereal rotation period that is similar Earth’s.
Observing the data provided in the table above, planets Mercury and Venus boast extremely high sidereal rotation periods, 1,407.5 hours and 5,832.5 hours respectively. With the Dwarf Planet Pluto and Earth’s Moon being the lesser of the extreme sidereal rotation periods at 153.298 hours and 655.718 hours respectively. To perform planetary terraformation on any of these celestial bodies successfully would mean that organic lifeforms originating from Earth would have to somehow adapt to extremely long days.
The table also displays planets in which the sidereal rotation period is extremely short in comparison to that of an Earth day. Examples of such planets would be the following: Jupiter (9.925 hours), Saturn (10.57 hours), Dwarf Planet Ceres (9.074170 hours). In contrast to the previous situation, humans would instead have to adapt to extremely short days, which could provide the same adverse effects that living on a planet with extremely long days could produce. Additionally, four planets within our outer solar system (Jupiter, Saturn, Uranus and Neptune) are gaseous planets and would increase the difficulty of planetary terraformation significantly due to the planets not having any known terrain to terraform in the first place.
Further observation of the table would show that there are planets that have sidereal rotation periods that are close to Earth’s sidereal rotation period. Uranus and Neptune have sidereal rotation periods of 17.24 hours and 16.1112 hours respectively, but both planets have the disadvantage of being gaseous planets as mentioned prior. However, there happens to be a planet that has a sidereal rotation period that is very similar to Earth’s and has the added benefit of not being a gaseous planet. At a sidereal rotation period of 24.6229 hours, days on Mars last only about 3 percent longer than days on Earth. At a glance, Mars seems like it would be the best candidate for planetary terraformation.
It should be noted that the length of the sidereal rotation period of Mars is not the only determining factor of candidacy for planetary terraformation. In addition to the advantage of having a similar sidereal rotation period to Earth, Mars has several other advantages that make it the likely candidate for planetary terraformation. As Vasileva et al. (2019) have stated, the advantages that Mars has that make it the most likely candidate for terraformation are listed as the following: A similar sidereal rotation period to Earth’s sidereal rotation period (as mentioned prior), the presence of frozen water on Mars as well as evidence that Mars used to be a warmer and wetter planet, the mineralogy and chemistry of Mars’ soil is suitable for life, and the presence of salts on Mars that are important to Earth-origin life.
With a candidate for planetary terraformation now chosen, we should now consider what is required to consider Mars a successfully terraformed planet capable of sustaining organic life originating from Earth. As previously discussed, Mars is the best candidate for a “Second Earth”. However, there are still major hurdles that need to be overcome as there are still some major differences between both planets. As an example, Mars has a surface gravity of (g = 3.711 m/s²) which is considerably lesser in comparison to Earth’s surface gravity (g = 9.807 m/s²). Another example would be that, Mars is also relatively colder (220K) in comparison to Earth (290K).
With these major differences in mind, we can now pinpoint what needs to be done in order to re-shape Mars into a “Second Earth”. As Paul Birch (1992) describes, in order to terraform Mars, we need accomplish the following three things: (1) Warm Mars to about 290K, (2) Increase the atmospheric pressure of Mars, supplying ~240 mbar of breathable oxygen, and finally, (3) Provide sufficient water to Mars in order to create a water-table and seas. Accomplishing these three things would result in the terraformation of Mars. However, the question still stands, “How are we to accomplish these things?”.
Mars is cooler on average in comparison to Earth due to it being farther away from the sun. Humanity would ideally seek to warm the temperature of Mars by ~70K in order to match it to the temperature of Earth. This could possibly be accomplished by increasing the greenhouse effect of the atmosphere of Mars. There have been several proposals to how humanity could increase the greenhouse effect of the Martian atmosphere. One such proposal suggests that the impact of ice asteroids could result in the increase of the greenhouse effect on Mars. Another proposal suggests that the release of artificial greenhouse agents could also result in the increase of the greenhouse effect on Mars. Unfortunately, according to Paul Birch (1992), such proposals “appear inadequate, uncertain, costly, or slow”.
However, there is one proposal that seems within realistic reach utilizing the technologies of Earth. This proposal involves positioning a large mirror in space between Mars and the Sun in order to assist in warming the planet. As seen in the figure above, this large space-mirror, also known as a soletta, is theorized to “augment the mean insolation and warm the planet (Mars) to any desired degree” (Birch). Birch (1992) then went on to further describe the process in detail: (The soletta) Manufactured in space from lunar or asteroidal resources, the soletta would consist of solar sail material – aluminized film of areal density ~3×10-4 kg/m-2. To match Earth’s insolation, an area ~2.5πR2 ~9×1013m2 would be required, massing ~3×1010kg… The sun’s track and appearance would then differ little from on Earth.
The cost of such a project is unknown, as there are no specific details on what materials the soletta would be. A soletta magnifying the sun would certainly raise the surface temperature of Mars to ~290K. However, the same cannot be said for the temperature of the Mars soil past 3 meters. The idea of the soletta is to heat up the remaining water on the planet, such that the volatiles (in this case, the important volatile being carbon dioxide) can replenish the atmosphere.
On the topic of the atmosphere, in order to make it a breathable atmosphere, there must be a supply of ~240mbar of free oxygen. If the soletta project is successful in heating up the soil of the planet, it is believed that the other volatiles (nitrogen and oxygen) would be liberated as well. As such, humanity would create a breathable atmosphere on Mars by warming the planet to our desired temperature of ~290K. However, as Birch (1992) states, “any excess carbon dioxide will have to be converted into oxygen”. One such way this can be accomplished is through the process of photosynthesis by plants, specifically grain plants, as they can handle the relatively low atmospheric pressure.
The growth and well being of these plants would require water, such that they can remove carbon dioxide from the air, as well as provide even more oxygen. At a glance, the planet of Mars seems to lack the very much needed resource of water. However, scientists have found that Mars does indeed have some water remaining in the form of the planet’s polar icecaps. Some scientists have also theorized the existence of water frozen beneath the surface of Mars. So, it is quite likely that Mars can provide a decent portion of the water required to complete the terraformation process.
Now that we have theorized what humanity can do, is it within reason? We know that there exists a suitable candidate for planetary terraformation in the form of Mars. However, according to recent discussions of the topic, the answer of “Can we?” falls into ambiguity. The reasoning for why the answer is ambiguous is described by Vasileva et al. (2019) as a result of the ambiguity of the term “terraformation”. The reason as to why humanity cannot produce a clear answer of whether it is or is not possible to perform planetary terraformation is because of the different ways that researchers may interpret the term “terraformation”. Can humanity reasonably create a “Second Earth”? It seems as though humanity currently cannot answer for sure, but the same could have been said for the possibility of space exploration in the 1960s.
As mentioned before, a common question that is asked when discussing the topic of planetary terraformation is the following: “Should we?”. Supposing that humanity did have the technology and the capability to perform wholescale planetary terraformation of Mars, is humanity within their right to make such extreme changes to the planet? Preservationists would say that we should keep the purity of the planet intact, and that any changes made to the planet intentionally would be considered wrong within our morality.
However, as Fogg (2000) describes, “the perceived problem with environmental ethics in its current form is tat it is geocentric in context”. Meaning that the issues that afflict us here on Earth, the moral issues of right and wrong, have no context within the vastness of space. The development of environmental ethics is reactive in nature to our response to environmental crisis here on Earth. However, if we were to travel outside the boundaries of our home, would it not make sense to have the approach to environmental ethics be proactive instead of reactive? Would we not have learned from the mistakes we have made and instead sought to prevent the same elsewhere within the cosmos?
One standpoint within the morality of terraforming Mars, by C.P McKay, says that the terraformation of Mars would be permissible provided that the planet was barren (McKay 1990). If there were to be life native to the planet found, it is within the moral obligation that humanity preserve that life and to maximize the richness and diversity of those indigenous life forms. In another standpoint by F. Turner (1994), it is within the moral obligation of humanity to terraform Mars. He views humanity as the bees of the universe, distributing the gift of life throughout the cosmos. He believes that we should do as such not because it is a poetically noble thing to do, but because it would also boost humanity’s confidence in how the planetary ecosystem works (Fogg 2000).
To answer the question, “Should we?”, would result in the same ambiguity that came from answering the question “Can we?”. There are too many different interpretations that humanity can go through when determining the answers to this question. It is within reason that humanity never know the true answers to these questions until we have accomplished the goal of terraforming a planet. However, if humanity were to attack this endeavor with the same zeal as we did in the 1960s, it is of my firm belief that we are entirely capable of performing planetary terraformation on such a scale.
- Birch, Paul. “Terraforming Mars Quickly.” Journal of The British Interplanetary Society, vol. 45, 1992, pp. 331–340., https://orionsarm.com/fm_store/TerraformingMarsQuickly.pdf.
- Earl, Michael A. “Calculating Earth’s Rotation Speed.” Canadian Astronomy, Satellite Tracking and Optical Research, 24 Dec. 2010, www.castor2.ca/16_Calc/03_Rotation/index.html.
- Fogg, Martyn J. “The Ethical Dimensions of Space Settlement.” Space Policy, vol. 16, no. 3, 16 July 2000, pp. 205–211., doi:doi.org/10.1016/S0265-9646(00)00024-2.
- Vasileva, Iv., et al. “TERRAFORMING MARS IS NOT OUT OF THE QUESTION YET – AND MICROSCOPIC ALGAE COULD HELP.” Trakia Journal of Sciences, vol. 1, 2019, pp. 8–12., doi:10.15547/tjs.2019.01.002.