Saturn has a strange serenity to it.
Looking at it through a telescope you see a generally unchanging orb crowned with its
magnificent rings.
This stands in stark contrast to its neighbor Jupiter, where the Galilean moons change positions
each night just as Galileo saw, and in a large enough telescope you see the great red spot,
and transient events happening in the atmosphere.
But Saturn visually rarely does any of that, though you can see Titan and some other moons
orbiting if you have a large enough telescope.
But Saturn also holds a very high long term potential for radical change.
The first is with the ring system.
Saturn’s ring system is rather mysterious in that we don’t know how they formed, and
we don’t know when.
Estimates of the time of the formation of the rings range from a mere 10 million years
ago, back to the formation of Saturn itself 4.5 billion years ago.
But what we do know is that the ring system is currently disappearing.
Part of the mystery of how old they are is in that they appear young.
Saturn’s rings are very bright, and almost entirely made of water ice.
Over time it’s thought that ring systems get polluted by collecting up dust and meteorites
causing them to darken.
So Saturn does not appear to have old rings.
But it’s hard to envision how they formed, leading to seemingly unlikely scenarios of
comets or moon collisions in the recent history of the solar system.
As a result, some researchers still favor an ancient ring system model.
But regardless, there is the problem of ring fading.
Material in the rings is in a constant state of collision and also gravitational interaction.
This causes a steady rain of material to fall into Saturn, which was found to be greater
than expected by the Cassini mission.
Saturn's rings are now thought to have less than a hundred million years left before no
evidence of them ever existing will remain.
Imagine Saturn without its rings, that would look weird.
It’s interesting to imagine far future humans holding fundraisers to restore Saturn’s
ring system in a museum-like atmosphere.
Save the rings, even if they have to be preserved or even reconstructed artificially to save
the Mona Lisa of the solar system.
But that’s not the only change that Saturn will undergo.
This is in regards to Titan, one of the most mysterious moons in the solar system.
Titan is slowly moving away from Saturn.
Our own moon is likewise moving away from us, but only by about 4 centimeters per year.
Titan on the other hand is moving away from Saturn at a rate of 11 centimeters per year.
It’s amazing something so tiny in comparison to its host planet can do this, but as Titan
moves outward it should affect Saturn’s spin and cause it to wobble on its axis.
This effect is so bad that it will eventually result in Saturn knocking itself on its side.
There is another example of this.
Something in the history of Uranus knocked it on its side, basically showing its poles
to the plane of the solar system.
It may have been a similar process that did this, though most models of Uranus favor a
huge collision with something having done it.
As Titan continues to migrate outward, it’s fate will become sealed and it will either
be ejected from the Saturn System to wander the solar system, or it will fall apocalyptically
into Saturn and be destroyed.
But this is all on very long timescales, billions to tens of billions of years, so this all
might not have time to happen.
The elephant in the room here is the red giant stage of the sun.
Towards the end of the solar system in about 4.5 billion years, the sun will swell and
swallow the inner planets, including earth.
Mars may survive this as a baked world, a cinder of its former self.
But what happens to the outer solar system?
While the outer planets may survive the red giant phase of the sun, their conditions will
be radically altered to the point that it’s notoriously difficult to predict.
But as the sun loses mass and becomes a white dwarf, the remaining planets will migrate
outward.
It’s thought that Jupiter and Saturn will fall into a new stable orbital resonance.
But not for long.
Over these time scales and in this new configuration the sun will encounter many other stars, some
close.
These stellar encounters will be what truly ends the solar system because with the giant
planets in more distant orbits, they will be more subject to perturbations by passing
stars and things will become chaotic and the remaining planets will one by one be tossed
out of the solar system to become rogue planets.
Eventually, they all probably go and the sun for the first time in its history will be
a lonely white dwarf, doing little but cooling down over immense amounts of time before it
becomes a black cinder.
But the wandering planets, Saturn included, may do so indefinitely.
It’s even conceivable that the galaxy itself might toss them out, in which case they will
be intergalactic rogue planets.
Or during the future collision with the andromeda galaxy, Saturn may end up being captured by
a star from another galaxy entirely.
Perhaps some far future alien civilization from Andromeda studying exoplanets will see
Saturn and take a look at its isotope ratios and conclude that it was a captured body.
What they would never know however is that it was once part of a star system that hosted
what would be to them an ancient alien civilization, us, that once actively probed this world.
But there is one last mystery with Saturn worth recounting here.
This is Saturn’s mysterious hexagon, a cloud feature of Saturn’s north pole.
This thing is unique in the solar system, and not entirely understood.
At its center is a vortex, so whatever this is it seems to be a phenomenon of high winds,
such as a jet stream arrangement.
It also changes color.
Over the last few years it has changed from bluish to a gold color.
Recent mathematical models have suggested a means of just how winds do this, and it
even predicts that it can happen on any gas giant with the right conditions of a storm
surrounded by a ring of winds moving in the opposite direction.
So this hexagon feature may be relatively common in the universe.
One wonders if you could have a situation somewhere in the universe where gas giants
have two huge hexagonal features at each pole making for a very strange planet indeed dominated
by these anticyclonic rings.
But this is a very vague area for us.
Planetary atmospheres are unbelievably complex, as our own atmosphere shows, and each one
is markedly different in our solar system.
What could be possible in the universe at large isn’t fully understood, and many different
atmospheric phenomena we haven’t conceived of could be occurring.
But there’s one more mystery regarding the hexagon.
The hexagon has a very specific rotation period of 10 hours, 39 minutes, 24 seconds.
For whatever reason, this coincides exactly with the period of Saturn’s radio emissions
from deep in its interior.
It’s unclear exactly why that is.
But what of the fate of Titan itself during this period of the sun’s red giant phase.
Well, this gets weird in that Titan is a very strange world indeed.
There is organic chemistry going on in its atmosphere, along with liquid hydrocarbons
on its surface acting very similar to earth’s water cycle.
This has led some to suggest that Titan could harbor some kind of low temperature life.
This would be beyond alien, when compared to earth life, in that it would use a completely
different solvent akin to lighter fluid instead of water and operate at much lower temperatures,
with much slower chemistry.
Life in slow motion.
This is interesting because it might turn out to be the only way in the solar system
that we can truly eliminate panspermic origins for the microbial life there.
It’s just too different of an environment chemically for earth life to have adapted
if it were deposited there.
If we end up finding microbes on any other planet in the solar system, they’re likely
to be water based, except at Titan.
While you should be able to tell if they are related by their genetics and even chirality,
that could be open to debate, as most things in science are.
But with Titan surface life, if it’s there, you’re probably not looking at a cousin
but an unequivocal second genesis of life in the solar system.
.
But titan is unique in that it offers two paths to life.
It’s also thought that Titan may have subsurface water and may in fact be an ice shell moon
with an entire subsurface water ocean.
But this ocean would have to be very dense according to recent work, which would mean
it’s not just saltwater, it’s some serious saltwater.
But we have that here.
Earth’s oceans average around 3.5 percent salt content.
But the Dead Sea is over 30 percent, which would put it on level with Titan’s subsurface
ocean.
Salinity that high is bad news for most life.
The dead sea is basically dead.
It’s just too salty for most things, but it’s not completely devoid of life.
There are microbes adapted to it, though they are very limited.
It’s not known whether life could arise in such salty conditions, but in limited form
here on earth it can survive within it.
And then there is the far future of Titan.
If it remains in the solar system, it may end up in a position where the sun’s red
giant phase could warm it and convert it into a water world.
During this process the sun’s output of Ultraviolet light will drop, which means that
Titan’s hazy atmosphere will clear, and begin to experience a greenhouse effect warming
its surface.
This state of affairs won’t last long, only a few hundred million years, but given that
life on earth arose at absolutely the earliest moment it could, then this offers Titan a
chance for life to arise.
If it had already done so long before and adapted to this new environment, even more
slowly than it happened on earth due to the abundance of ammonia on Titan, maybe even
the evolution of complex life in the far future could be on the table.
Maybe the end of life in the Solar system is destined to be the analogues of fungi or
plants on Titan.
An odd far future indeed.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently worried about future
aliens exploring the solar system.
They’d probably never know Earth existed during the red giant phase of the sun, and
probably wouldn’t know about us and just found Titan as a world of horrific carnivorous
mushrooms orbiting a red giant that’s past its expiration date.
Best to just move on to the next system and mark this one as just not great for vacationing
and be sure to check out my books at your favorite online book retailer and subscribe
to my channels for regular, in-depth explorations into the interesting, weird and unknown aspects
of this amazing universe in which we live.