You must have read or seen in the science fiction movies about the idea of colonizing some other planet. One such planet that most of the people have seen in the movies and also scientists consider it as an alternative in far future is, Mars(although Elon Musk has said that he will colonize Mars by 2022 ). In this article, I will discuss another alternative habitat in our solar system: Titan (largest moon of Saturn).
Figure: Above figure showing the order of distances of various planets from the Sun.
First, I will discuss that what kind of conditions are needed for the survival of humans (and generally other earthlings too). My general strategy would be to throw the possibilities off the list one by one on the basis of different factors.
Temperature:
First and foremost thing is that the temperature of the celestial body. It should not be too cold or too hot either. That means, the planets like Mercury being very close to the Sun are off the list immediately because the temperature there can go up to 450 ° C. It is extremely hot during the day and very cold during nights. Also, Venus is extremely hot and we can not consider it as an option for colonization. Also, the planets which are very far from the Sun ( e.g. Uranus and Neptune) being extremely cold cannot be considered very viable either as they receive very less light from the Sun and we will have to use a lot of power to keep yourself warm. Although, we can use some nuclear reactor to generate power but that might not be possible everywhere. Although we will have to build some kind of thermal shield.
Therefore, we are left with only a few planets which are Mars, Jupiter and Saturn and possibly their moons.
Water:
One of the first things that many people ask about a planet is whether there is water or not. After the temperature of the surface of the planet, we will have to look for the most necessary component i.e. water. Saturn itself has some amount of water on its surface but not too much. Also, Jupiter has only trace amount of water on the surface although some amount of water is found on its moons e.g. Europa has water in the form of ice. But still, we are not very sure of that. Some scientists say that the Europa's ocean is not water but concentrated sulphuric acid. So we can right away discard this possibility as of now.
After this filter of water, we are left with Mars and Saturn's moon and of course Earth's moon.
Atmosphere:
Apart from these, one of the prime concerns is the atmosphere. Having an atmosphere has many advantages such as protection against harmful radiation, space debris, maintaining a temperature. Earth's moon has virtually no atmosphere. This results that the surface of the moon is badly exposed to cosmic radiation.
So it will be very hard to survive on the moon for a long time, leave aside the colonization. Now we have only Mars and Saturn's moon Titan (as others are not fit because of one or the other reasons mentioned above).
Hydrocarbons:
Earth has carbon-based life and we have to have hydrocarbons in order to survive in any other place. Mars is known to have some amount of hydrocarbon, but Titan has the same a lot more. It has hundreds of times more oil than the Earth has.
I will here on compare mars and titan for habitability.
Mars is much closer to Earth than Titan. It takes about 7 months to reach Mars while it takes 7 years to Titan. So in terms of fuel efficiency, Mars is a much better option. Also, the time to contact the people by other means on Titan will be much larger than that for Mars.
Mars is closer to Sun, therefore we can use solar energy. On the other hand, Titan receives very less amount of light. But we can use the oil sources for energy.
Mars being closer to the Sun receives lot more radiation than Titan. So we can live on Titan as long as we want contrary to the Mars where we have to hide under the surface.
Titan has a dense atmosphere made primarily of nitrogen (which is found 78% in earth's atmosphere), while Mars has a very thin atmosphere made of carbon-di-oxide. So as I discussed above, Titan has an advantage in this field.
The day on Mars is approx 24 hrs and 40 minutes while it is 16 days on Titan. So Mars day is much more suitable for our biology.
The gravity on Mars is 38% while on Titan it is 13% of Earth's gravity. So it will be much easier for us to manage on Mars in terms of gravity.
We saw that there are some ways in which Mars is better than Titan while in some Titan is better than Mars. But anyways Mars will probably be colonized first.
In this article, I have left many important points. There is a lot more to cover and probably, I will do that in future articles. Please share your thoughts and feedback in the comment section.
Thanks for reading,
Kamal Tripathi.
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