The existence of other complex life in the universe may seem unlikely given the long
convoluted chain of events that produced life on earth, but we can't rule it out.
If just one in every hundred trillion earth-like planets produced living beings.
There could still be thousands of planets filled with alien life.
With all these potentially habitable planets, it's worth asking, what would life look like
on alien worlds?
Be sure to check out our parts 1 and 2 after this and let’s jump in.
If you saw our planet from space you’d see a tiny blue dot covered by green vegetation.
Forests cover a third of the planet's land area and thanks to their chlorophyll, they’re
the luscious green color we’ve come to know.
Our sun gives off more light in the green part of the visible spectrum than any other.
Since most plants look green, this means they aren’t absorbing this green light.
It might seem rather strange and inefficient that plants don't absorb what our sun produces
the most of, but this is actually a form of protection.
Plants would overdose themselves in energy if they tried absorbing this green light,
so instead they absorb the less present blue and red parts of the spectrum.
But what if a world was much further from its sun than Earth.
Far enough that plants could absorb the green spectrum of light without being damaged, emitting
blue and red light.
What would life look like on a purple world?
Here on Zantar, everything is purple.
Plant life covers the archipelagos, but even the seas have a definitive purple tint thanks
to bacteria floating on the planet's oceans.
Here retinal, as opposed to chlorophyll, gives life it’s purple tint.
The planet is so far outside it’s sun’s habitable zone that these oceans should be
frozen solid, but strong undersea thermal vents from the planet's molten core supply
enough energy to keep them liquid.
But this planet is quiet.
No animals roam its surface, no birds fly in its skies.
How could a planet covered in lush vegetation sit empty for hundreds of millions of years.
The answer is Mayacroom, a fungus that dominates the planet.
Normally it subsides on decaying plant matter across the planet, but every few millions
years, as mutations give rise to more complex life, Mayacroom infects and eliminates it.
The fungus has a death grip on the planet.
Mayacroom isn’t simply a species of billions of individuals that collectively shape the
planet like the chimp-like creatures that govern Earth.
Over a billion or so years it interweaved a root system spanning the planet.
As it evolved it eliminated other animals that fed on the planet's vegetation, challenging
the fungus’s food source until it was the sole inhabitant of Zantar.
It may not be sentient life how humans would normally perceive it.
It doesn’t go to work, or paint pictures, or stare at the stars, but it can react to
threats and environmental stressors, sending nutrients throughout its root system across
the planet and seemingly consciously reacting to problems.
Where would a fungus, even a planet sized one, store it’s consciousness that allows
it to respond to such advanced, planet spanning problems?
Well, where do humans store their consciousness?
It can’t simply be in their brains.
Octopus are thought to be amongst the smartest creatures on Earth, but yet they don’t just
have a centralized brain.
Instead, they have neural tissue distributed in each of their arms.
Perhaps the Mayacroom’s sentience is in small pieces spread over thousands of roots
and spores.
A planet like this could force humans to re-evaluate how we think of advanced alien life.
Like the flood from Halo, the Mayacroom is able to act as one species governing the planet.
As other life forms evolve, ones that could compete with it for the plant's vegetation,
it purposely infects them to ensure it’s control over the planet.
If the alien movies ever taught us anything, it’s that if humans ever find a planet like
this, they need to get out fast.
*play movie clip* And we all know how that went….
But what would life look like across the galaxy?
Thousands of light years away, on a planet lost in time: Calax.
Instead of humans making Jurassic Park, imagine a world we could visit filled with dinosaur-like
creatures.
Have you ever stopped to wonder why dinosaurs were so much bigger than the animals we see
today.
Most dinosaurs weighed close to a ton, if not hundreds.
Even scavengers and plant eaters were about this size.
But today, many apex predators like lions and tigers aren’t even half that.
One of the leading theories is because of the higher levels of carbon dioxide in the
air.
Plants in carbon rich environments grow fast but actually have fewer nutrients then if
they grew in an environment similar to what we have today.
As a result animals needed to eat a lot of plants just to get enough energy to survive
and so they developed larger stomachs to handle more food.
Naturally they had to grow bigger to carry this bigger stomach.
Some Sauropods maxed out their food eating stat by basically being walking stomachs.
They had a long neck so they could eat everything in front of them without having to walk anywhere.
Moving that much mass required a lot of energy so instead they stood still and swung their
necks around eating everything they could reach.
When all the food was gone they just took a few steps forward and could reach a literal
ton of new food.With plant-eating dinosaurs getting bigger, the carnivores needed to get
bigger to be able to take them down.
So on an alien world with 1% carbon dioxide, more than 20 times the amount in Earth’s
atmosphere today and 5 times more than what existed during the cretaceous period.
This is Calax.
Plants have less nutrients and so the creatures grow massive.
One example is the Larensis, a giant and unusual creature.
It’s developed a mutually symbiotic relationship with plants on this world.
Carrying around special trees on its head, capable of cross pollinating the plants it
eats.
Not every creature has such a vegan lifestyle.
Since dinosaurs are so large, they're far too much for even a herd of apex predators
to eat, so on Calax, scavengers like the 15 foot, bone headed Hammerskull have plenty
to eat.
They roam the planet, scavenging for scrapes left behind by the planet's predators, and
occasionally eating smaller reptile-like creatures.
And while we’re looking at an eye, it’s a good time to point out how incredibly resource
intensive they are to make.
So for a slow creature without many natural predators, why make two when one can do the
trick.
Some creatures on Earth, like flatfish and flounder, only have eyes on one side of their
body.
But why limit vision.
Instead, this creature can move its eye from one side of its body to the other.
This is how life could evolve on an extremely CO2 rich world, but what about life a few
light years away in a neighboring solar system?
When we search for life across the universe, we tend to look for life similar to ours.
We scan the atmosphere of exoplanets looking for the tell tale signs of oxygen and methane
that could be given off by alien life.
But this is a very earth centric view of extraterrestrial life; one that centers around carbon.
Carbon is ubiquitous, it's one of the most common elements in the universe and it's very
good at forming large stable molecules.
Carbon has the rare ability to form four way bonds with other elements and to bind to itself
in long stable chains, enabling the formatting of huge complex molecules.
This versatility makes carbon the centerpiece in the molecular machinery of life.
But carbon is not alone in this regard, these are traits shared by other elements on the
6th column of the periodic table.
Just one spot below carbon is silicon.
Silicon also has four valence electrons, meaning it can readily make bonds with other elements
and form complex structures.
What would life look like on a world dominated by silicon life, rather than carbon?
This is Titan, a giant rocky world.
Like the Titans from ancient mythology, this planet is monstrous.
It’s 12 times the size of our planet, at the very limit of what a rocky planet could
be before gravitational forces transform it into a gaseous giant.
Despite carbon making up almost 20% [18.5%] of our bodies, it only makes up .03% of the
Earth.
On a planet of Titan’s size, the atmosphere extends 8 times further from the planet's
surface.
Because CO2 is much lighter than SO2 (the silicon based equivalent), CO2
floats much higher in the planet's atmosphere, where it slowly gets ripped off the planet
by the strong solar winds of Titan’s sun.
Over a billion years or so, this left the planet with nearly no carbon.
But life finds a way.
* And on Titan, silicon was that way.
The main life forms across this planet are Silanes, short four legged creatures that
walk across the planet's surface.
Over eons, the planet's fast winds created by the extreme atmosphere carve out the planet's
rocky surface, much the same way water erosion works on earth.
Titan has an incredibly charged atmosphere.
Think lighting storms covering the planet 24/7.
The Silanes have harnessed this energy, and use it to power life and communication.
And by filling and emptying a bladder within themselves, they can change their buoyancy
and swim through the thick atmosphere.
But the Silanes aren’t the only creatures that call Titan home.
The leviathans, yep, the same ones Loki commanded in the Battle for New York, call Titan home.
What are your thoughts on these imagined alien worlds?
Are they believable or a little too far fetched.
Do you have your own worlds you’d like to see brought to life?
Let us know in the comments below.
Maybe your idea could be brought to life in part 4.
And remember, there is always more to learn.
This is how life may have adapted to live on these three imagined worlds.
But how would life evolve to live on a world twice as big, with twice as much gravity as
Earth.
Or on a planet so close to its star it’s tidally locked, so as it rotates it only ever
shows the same face to its sun.
Watch parts 1 and 2 to find out.
And remember, there is always more to learn.