When it comes to promising, Earth-like locations in the solar system, there’s perhaps one that
sits above all the rest. It’s not Mars, or Venus, and it’s not even the much discussed Jovian moon,
Europa: it’s Titan, our system’s second-largest moon and the least-alien alien world out there.
But why does Titan seemingly resemble our home planet quite so much?
This is Unveiled, and today we’re exploring new research into the Saturnian moon, Titan,
a prime contender for off-Earth life.
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Currently, we still have no definitive proof that life exists beyond planet Earth. However,
it seems highly likely that it will have developed elsewhere in the universe,
given the variety of life on our own planet and the abundance in the cosmos of the necessary
elements. It’s perhaps even possible that alien life exists, or at least once existed, in our
very own solar system. It’s thought that both Venus and Mars were hospitable once upon a time,
for example, millions of years before they assumed their current conditions. Saturn’s moon Titan,
however, remains promising even today, especially from a distance. It has several features that
are remarkably familiar to us, including liquid lakes and a nitrogen-rich atmosphere. It’s also
the same size as a planet (even though it’s only a moon) being, as it is, larger than Mercury.
However, for everything on Titan that apparently resembles Earth, there’s a bizarre twist that goes
to show just how alien this place still is. In 2022, scientists from Stanford University made
a statement about how similar Titan and Earth look… but they truly meant it in a literal
and superficial way. Yes, Titan LOOKS like Earth, but it doesn’t much behave like Earth…
and its Earth-like features are often made of far weirder materials than you’d expect.
For a start, those massive liquid lakes. They’re not made of water. They’re primarily made of
liquid methane and ethane, which you definitely can’t drink. If you stood on Titan’s surface,
these lakes would have a yellowish tinge thanks to the makeup of the moon’s skies.
Then there’s the sky on Titan… it’s filled with clouds that rain like ours do,
only again it’s methane. There may be active cryovolcanoes out there, too, blasting out frozen
molecules as opposed to molten rock. And it’s all extremely cold out there, with haze in the
atmosphere reflecting away sunlight, meaning the surface of Titan receives 99% less sunlight than
Earth’s - which puts its average temperature at roughly minus-296 degrees Fahrenheit.
Titan does however have certain sedimentary rocks that are very similar to Earth’s. Called “ooids”,
these spheroidal grains are made of calcium… and they form rock features known as “oolites”. While
this may sound mundane, it tells us a lot about how Titan has a sedimentary system much like on
Earth, involving erosion, drift, and the formation of dense rocks as sediment gets dispersed by wind.
It’s one natural system that aligns it with us. Similarly, Titan’s methane lakes likely suffer
from coastal erosion just like Earth’s shorelines do, thanks to the storms that are there and the
liquid transport cycle – which is much like the water cycle, only with all that liquid being
methane instead of H2O. So, we can broadly say that Titan looks like Earth because it has many
of the same active systems as Earth does - even if they’re driven by different things.
Titan’s methane lakes aren’t completely alien either. Earth also has these, too, in a way. We
don’t have lakes made of pure liquid methane, because Earth isn’t cold enough for methane to
change from a gas into a liquid… but we do have lakes with lots of methane inside of them, thanks
to decomposing bodies at the bottom. Not masses of human bodies, thankfully, but just the circle
of life taking its toll on the many creatures that live in those particular lakes. The methane
released by their decomposition is then sometimes frozen in spectacular and very distinct bubbles,
visible prominently in Lake Abraham in Canada, for example. These bubbles, beautiful as they are, are
then quite dangerous… because, with global warming processes threatening to dramatically change the
status quo, this previously trapped methane could soon be released back into the atmosphere as gas.
This is something that Earth and Titan don’t have in common; Titan is going to remain frosty
forever, and it’s probably better off that way. So, if Titan (despite looking quite like Earth) is
actually so cold and abundant in liquids we can’t drink, why are scientists still so interested
in it? Well, when it comes to exploration and potential habitability, it’s for one thing better
to have a place that’s too cold than somewhere that’s too hot. Extreme heat is why we’ll likely
never be able to send humans to the surface of Venus, and why all Venusian probes have failed
very quickly thus far. The Venera 12 probe arrived on Venus in 1978 and lasted for a record-breaking
110 minutes before failing, and that’s still the longest-lasting one we’ve ever built.
On cold planets, however, like Mars, where winter temperatures can plummet to minus-220
degrees Fahrenheit, we’ve had rovers that last for decades. The same would likely be true of Titan.
The great thing about Titan is that its temperatures are relatively stable,
despite being so low. Because it’s so far from the sun, it always stays pretty cold, never reaching
the high temperatures that even the moon or the exterior of the ISS are subjected to. The surface
temperature of the moon, for instance, ranges from minus-280 degrees Fahrenheit to an eye-wateringly
hot 212 degrees, far hotter than the hottest recorded natural temperatures here on Earth. Our
machines (and, in a few cases, people) obviously survive up there, but it means that any potential
bases built on the moon have to withstand both incredibly low and incredibly high temperatures,
which can be tricky to manage. Titan, with its consistent, low temperatures by comparison,
is great for a climate-controlled human outpost. It has another big benefit, too, though: pressure.
Though Titan’s gravity is only 14% of Earth’s, the pressure is just 1.5 bars. For comparison,
2 bars of pressure are equivalent to diving roughly 30 feet beneath the surface of the ocean.
While this may be a little uncomfortable, it’s also workable. On Titan, it means that
pressurized suits and habitats would be able to easily mimic Earth’s conditions. In some ways,
living there would be like building a submarine that never needs to go deeper than 30 feet beneath
the water… a pretty easy engineering challenge. The large amount of nitrogen in Titan’s atmosphere
is potentially a plus, as well. 78% of the air on Earth is made up of nitrogen, too, with just 21%
being oxygen - despite oxygen being what we most need to stay alive. Titan’s atmosphere (as it is)
is roughly 95% nitrogen and 5% methane, so we still couldn’t breathe it… but having a massive
amount of nitrogen already there could make it far easier to create breathable air in the future.
Finally, Titan’s atmosphere has another helpful feature: it can block radiation. That’s one of
the biggest problems with trying to settle on the moon, Mars, or even in an orbital station. In all
those places, the small or even total lack of atmosphere means that solar radiation can
bombard completely uninterrupted, causing untold complications for space travelers. On Titan,
though, the thicker, denser atmosphere combined with the moon’s sheer distance away from the sun
means that there should be very little radiation, by comparison. Someone on Titan
might even have to worry about the dangers of light even less than you do here, on Earth.
Though there has historically been much less focus on Titan compared to Mars and even Venus,
it’s clear that that’s all starting to change in the twenty-first century. In 2004,
the Cassini probe undertook flybys of the moon, and sent down a lander, Huygens. And there are
finally further missions on the horizon to visit Titan again. Set to launch in 2027, Dragonfly is
a robotic spacecraft that will be able to fly through Titan’s atmosphere, hence the name. And
this little guy is actually the final iteration of a long line of proposed missions to the moon,
with some involving high-tech hot air balloons. Dragonfly’s aerial capabilities
mean it will hopefully be able to travel further and faster than the Mars rovers, as well. If all
goes to plan, though, it’ll land on Titan in 2034, and from that point will provide an untold wealth
of data, sending back high-quality images of that surface and those lakes that look so like our own.
And, hopefully, in time we’ll be able to determine whether Titan is hosting life, or could do in the
future. Lifeforms on Earth have of course thrived in even the darkest, coldest, hottest, and most
hostile of places, so it may be that this far off land isn’t actually so impossible, after all.
In many ways, it’s just like Earth, but in others it’s a wholly alien prospect…
and that’s what makes it a prime target for arguably one of the most exciting
space programs in modern times. What’s your verdict - is Titan the place to be?
What do you think? Is there anything we missed? Let us know in the comments, check out these other
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