With all of the recent excitement surrounding SpaceX and its proposition to colonize Mars, it’s a good time to take a step back and consider the circumstances. Although Mars has the potential for colonization and human habitation, there are several other available alternatives.
One astronomical body that may not immediately come to mind is Titan, the sixth moon of Saturn. The surface temperatures of Titan can reach -300 degrees Fahrenheit, and the surface gravity is around 0.14g (0.14 times the gravity of Earth). At first glance, Titan probably does not seem ideal for long or even short-term human habitation. However, one of its key advantages is its thick atmosphere, which is around 1.45 times thicker than that of Earth’s 1 atmosphere (1 atm). Compared to options like Mars (0.006 atm), the Moon (no atmosphere), and Europa (9.87 x 10-14 atm), this is extraordinarily similar to that of Earth.
Having a thicker atmosphere than other alternatives provides numerous advantages to colonizing Titan, an important one being increased protection from radiation. Around gas giants such as Saturn, radiation is more intense due to the planet’s massive gravitational field. Such high levels of radiation can disrupt communications and electronics, as well as potentially leading to negative short- and long-term effects on the human body, including radiation sickness and cancer. Earth’s thick atmosphere blocks most dangerous radiation from the sun, allowing us to live relatively protected. Titan has the same advantage with an even thicker atmosphere, which would allow us to live with extreme radiation protection.
The other main advantage of such a thick atmosphere is that EVA (Extravehicular Activity) suits wouldn’t have to be pressurized, and would only have to include insulation and an oxygen supply. Overall, Titan’s environment would facilitate an easy process of preparing to send bodies into space. Habitation structures could also be relatively unpressurized, allowing them to be lighter and easier to construct.
Titan also has lakes and seas, which are comprised of methane and ethane. Both of these chemicals can be used in rocket fuel, which, combined with the low gravity, would allow for easy launches of ships for transport or other purposes. The fuel produced can also be used in fuel cells, which would be a convenient source of energy for inhabitants of the moon, as the thick atmosphere and distance from the sun would make solar panels an impractical energy option on Titan’s surface. Methane could also help produce plastic, which would be used for unpressured living environments on the surface.
However, there are some downsides to colonizing Titan. The trip to Titan is extremely long, as Saturn is the third farthest planet from the Sun. With today’s technology, it is estimated that it would take at least six years for humans to reach. This prolonged journey would cause astronauts to be exposed to dangerous levels of radiation, as well as prolonged subjection to microgravity, which causes long-term bone degeneration. That being said, the medical effects of life outside of Earth are still largely unresearched, and before colonizing space, intensive medical studies must be conducted to determine causes and cures to ailments caused by different atmospheric conditions. There is also a much longer communication delay due to the speed of light and the immense distance between the Earth and Saturn. This could potentially be dangerous for those making the journey, as their contact with those back on Earth could be lost.
Overall, there are benefits and disadvantages, as with every planet, to traveling to and colonizing Titan. In the past, several of NASA’s missions have passed by Titan, including the Cassini-Huygens probe, but missions must be designated with the specific intent of researching Titan. A proposed mission to the surface is being considered for 2025, to be launched on the in-development Space Launch System. Hopefully, researchers will learn more about this moon, because it remains a prime option as we extend our reach across the solar system.