Mankind has been unrelenting in its efforts to search for extra-terrestrial life. Somehow, asking ‘Are we alone?’ generates a unique emotion every time you bring it up. Innumerable spacecrafts have been deployed to look for life (more than 150 at last count) and research the surface and atmospheric conditions of worlds yet unexplored.

The ones that have piqued our interest the most include Europa, Ganymede, Saturn’s Titan, and of course Mars. Mars get its fair share of attention, and a mission to Europa is in the works already. But Saturn’s Titan could be in for a Pandora-like treatment as in Avatar, not very far into the future.

Also Read: Wanderers – Humanity’s Future in Space

The ringed planet’s largest moon Titan is teeming with oceans of hydrocarbons. Data collected by the Huygens-Cassini spacecraft shows that Titan, which is 40% more massive than Mercury, has hundreds of times more liquid hydrocarbons by volume than all the known oil and natural gas reserves on Earth. 

 

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An image from Huygens on Titan. The first from a non-planetary entity, apart from the Moon

Chasing Titan

We’ve been interested in Titan for quite some time now. Aside from having a visually appealing host planet, Titan itself bears a ton of similarities to Earth – to the point that NASA sent a flagship class probe way back in 1997  – Cassini – to have a closer look at these worlds. Cassini was equipped with Huygens – a lander that set itself on Titan some time after Cassini achieved Saturn orbit in 2004.

Huygens sent us the very first pictures from Titan’s surface. It was, and still is, exhilarating to be checking out pictures from a world so vastly distant.

Titan is basically Earth, almost

As Cassini continues its study of Saturn and its system of moons, data from the probe indicates that the atmosphere of Titan is largely nitrogen. Minor components lead to the formation of methane-ethane clouds and nitrogen-rich organic smog.  Additionally, Titan has earth-like surface features like dunes, rivers and seas of liquid methane-ethane. Just like earth’s water cycle, Titan is said to have a methane cycle, only at a much lower temperature.

Besides it’s abundant oceans of methanes, Titan has been observed to have cryovolcanoes – volcanoes which erupt water and ammonia, which suggests presence of water under the surface.

Titan also happens to be the only other celestial body in the solar system apart from Earth which is confirmed to have stable bodies of surface liquid. Huygen’s successful landing on Titan also makes it the most distant landing by any human made craft. We should be proud.

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Titan, as captured by Cassini, 2005. The dark region in is Shangri-La. It is believed these were seas that have dried up.

If the data from the Cassini-Huygens spacecraft is indeed accurate, then Titan could well be the best candidate for extra-terrestrial life.

Related: To Mars, Via Antarctica

Why Colonise Titan?

As for human colonisation, certain conditions make Titan an ideal option. The water under the surface could be used to generate breathable oxygen while the nitrogen would be ideal to add buffer gas partial pressure to breathable air. Nitrogen, methane and ammonia can all be used to produce fertilizer for growing food.

Energy

Titan has a rotation period of 16 days, with a perpetual orange haze filling your vision when it is day time. At a distance of 10 AU from the Sun, the sunlight it receives is barely 1% that of the Earth – which means any future human colony will need to require on nuclear power (or its methane bodies) for its energy requirements. There’s of course, the problem of getting humans to traverse 9 AU to get to Titan in the first place – a trip that took Cassini over 7 years. But let’s hope we figure out faster space travel techniques in the future.

Atmospheric Pressure

Titan has a surface pressure equal to 1.5 times that of Earth’s – or the same as 5 meters underwater on earth. This eliminates complex engineering of spacecrafts and space suits to maintain ideal pressure conditions to prevent humans from imploding. In fact, you can stand on Titan without a spacesuit, wearing just an oxygen mask. If that isn’t cool, I don’t know what is.

Low Radiation

Aerospace engineer Robert Zubrin identifies Saturn as the most important of the gas giants due to its relative proximity and low radiation. Current human technology for radiation protection isn’t mature. Assuming the rate of advancement isn’t radical, Titan offers no issues for us to face on the radiation front.

Weather

Since Titan has a low surface temperature but a higher surface pressure, it leads to smaller atmospheric disturbances like winds. This could enable building robust engineering structures with little complex engineering.

But the extremely low surface temperature makes surface life as we know it impossible. Earth-based-life relies on chemical action in water solution. At -100 oC the rate of chemical reactions would likely be too low for complex organisms , and cells would freeze and burst. Hence, we would need an artificial environment which would help us maintain and regulate our body temperature on the surface of Titan.

Oxygen?

Titan’s atmsophere has no oxygen. Instead it has a high concentartion of Nitrogen, and methane-ethane. It also has trace amounts of Hydrogen Cyanide, which may not be deadly, but could cause dizziness in humans if breathed directly. But HCN is really not our major concern. With such a high concentration of methane, disorientation due to methane toxicity would be inevitable.

Gravity

Titan’s surface gravity is 14% of earth’s. And hence, any long term human colony there would need to cope with and manage the effects of microgravity like reduced bone density, muscle deteoration and weaker immune system. Add to that the hazy effects of microgravity on fetal development, and this becomes a very serious issue if we plan to start a human colony on Titan.

So all in all, practicable human colonisation on Titan remains a tough feat to accomplish. A lot of careful planning and pathbreaking engineering is required on our part, if we ever want to colonise Titan. But isn’t that the case with any world outside of our own? Titan just happens to be slightly on the easier side by the looks of it. NASA has been engaged in meticulous planning for the manned mission to Mars for years now, and the most important aspect of that would involve keeping the humans alive in those harsh conditions and minimal atmosphere. With Titan, the complexity cannot get any bigger.

If Mark Wattney could grow crops on Mars all alone, we sure can live on Titan.