The far future of the solar system will see drastic changes and events unlike anything
we have experienced in human history.
And it will be to the point that it will be difficult to recognize our home star system
when compared to what it is now.
Some of these events will be quite spectacular, so here are ten mind blowing future solar
system events.
10.
The Planetary Nebula
One of the most beautiful objects we see in the Milky Way is a planetary nebula.
The name is a misnomer, these nebula have nothing directly to do with planets, rather
they were seen to be planet like in early telescopes and the name stuck.
Planetary nebulae occur when stars shed their outer layers into space, creating an expanding
nebula.
This happens at the end of their red giant phase, to stars between one and eight solar
masses.
Essentially what happens is these red giant stars evaporate their own atmospheres into
space, causing a short lived but beautiful planetary nebula, illuminated by the ultraviolet
light from the exposed stellar core lasting about ten thousand years.
New modeling suggests that this is what’s in store for the sun at the end of its life,
and our planetary nebula while dim, would be visible not only to the rest of the Milky
Way, but neighboring galaxies such as Andromeda, which by this time will be colliding with
the Milky Way.
The sun is at the very lowest limit to be able to produce a visible planetary nebula,
but the modeling shows that the core will be hot enough to illuminate the nebula.
Given that this event lies billions of years in the future, that’s enough time for other
civilizations to develop in the galaxy, and nearby galaxies, possibly in an intelligence
explosion in the universe that may come as time passes.
We will be long gone, earth will at least be a cinder, if not utterly vaporized by the
sun’s red giant phase and making up part of the planetary nebula.
But it’s interesting to imagine some future alien civilization studying the planetary
nebulae of the Milky Way, noticing one in particular but never realizing that there
was once a civilization in that star system, full of hopes and dreams, but having gone
extinct long ago.
Or maybe they’re still around, and studying the planetary nebula from some new home, perhaps
never realizing that it was where they originated.
9.
The Rings of Neptune
As it stands today, while Neptune currently does have a faint ring system, it’s nothing
close to the absolutely stunning rings of Saturn.
But rings are transient things, Saturn only has about three hundred million years left
having them, as they are slowly but surely degrading and falling into the planet.
This will leave a time in the solar system where it has no prominently ringed planets.
But in the far future, it will again, but not at saturn.
Instead, it will be Neptune that forms a spectacular ring system.
In about 3.6 billion years, Neptune’s largest moon Triton will cross the ice giant’s roche
limit and probably disintegrate and form an extensive ring system, possibly even more
spectacular than that currently at Saturn.
Ring systems in the universe can get much more extensive however, the exoplanet J1407B
is known to have a ring system two hundred times more extensive than Saturn.
Imagine what that looks like close up.
8.
The Age of Oceanic Habitable Moons
Currently, the sun’s habitable zone is relatively close in, and we’re inside it.
But as the sun ages and expands into its red giant phase, the habitable zone will move
outward.
It’s unclear just how much the sun will expand, and that greatly affects the equation
of what will end up in the new habitable zone during this process, but it’s possible that
at least some of the outer solar system’s ice shell moons might thaw and host surface
oceans suitable for life, if it’s not already there deep in the oceans under the ice shells.
This opens up the possibility for Europa, Ganymede and Callisto to thaw, and possibly
even Titan and Enceladus at Saturn, again depending on how much the sun expands.
If it goes too far, the oceans of the moons of Jupiter will boil away, but perhaps favor
the Saturn system, If it goes the other way, then three habitable ocean moons could exist
at Jupiter.
If any of them currently have life, that life may undergo a major change in evolution to
favor the new reality of surface oceans.
But it won’t last forever, as the sun continues to age out of its red giant phase and become
a white dwarf, these oceans will freeze solid and very likely end life on those worlds should
it come to exist.
7.
Human Expansion And Colonization
Perhaps the greatest potential for change in the solar system lies with our own species
and technological development.
We hold, in principle, the eventual ability to colonize our star system and even terraform
some of the worlds present within it.
As a result, should we survive into the far future, we could see a day where the bodies
of the solar system are radically altered, and even our supply of asteroids could end
up mined out.
One could envision, with great difficulty, a terraformed Mars and Venus existing eventually
with earth-like conditions, and megastructure arrangements designed to keep Venus cool,
such as with a huge sun shade in space, and Mars with an artificial magnetosphere, plans
for which already exist and simply requires, in a nutshell, a small magnetosphere generating
spacecraft placed in between the sun and Mars.
For something that sounds so daunting as an artificial planetary magnetosphere, it’s
actually straightforward and not that difficult, and could be done with today’s technology.
We may even someday be able to change the nature and lifetime of the sun itself, it
is possible to engineer a star through techniques like stellar lifting and get rid of the pesky
helium building up inside the sun that will drive its demise.
Whether we ever do anything like this remains to be seen, but there are hypothetical ways
we could dramatically alter the solar system.
6.
Warm Mars
It’s well known that Mars was once a habitable water world, much like earth, and may have
spawned life.
Indeed, due to panspermia, it’s possible that Mars was the origin of life on earth
that was deposited here by a meteorite.
Mars today is far from habitable, though there may be pockets and possibilities for microbes,
but the surface seems too harsh for life as we know it.
But what isn’t commonly known is that Mars could in the far future see a second period
of habitability, at least for a time.
The idea is that in about 6.5 billion years as the sun is entering its red giant phase
Mars will start to receive about the same amount of solar radiation that earth is getting
right now.
This may open the way for a period of surface liquid water as the copious amounts of water
ice melts on that world.
It wouldn’t be as extensive as earth, which by this time will have lost its water, but
it’s possible for a time that some water might be at the surface.
It’s also possible of course that by that time we will have terraformed Mars and are
inhabiting it as a temporary stop gap as Earth is destroyed.
But this won’t last long, as the sun continues to swell Mars will share a similar fate to
Earth be scorched.
Any humans left will be forced further out into the outer solar system.
5.
The Changing North Star And the Future South Star
Known as precession, earth’s poles point at an area of the sky that over long periods
of time moves, tracing out a circle in the sky.
But it’s not that long of a time, and indeed there have been humans in the past that had
a completely different north star.
The current one, Polaris, won’t be the north star any longer in the future, and while we
currently don’t have a southern pole star useable in navigation, in the future there
will be one.
The next northern polar star will be Gamma Cephei around 3100 AD.
In the southern hemisphere, navigation used the southern cross as a pointer to where a
polar star would be.
But due to precession, that will change, and indeed it has.
There was a time that the ancient greeks could actually see the Southern Cross, but no longer.
In about 7500 years however, the star Gamma Chamaeleontis will become the southern pole
star.
But stars also move on their own through space, known as proper motion.
This will have an interesting effect, the brightest star in the night sky, Sirius, will
move into position and become the southern polar star sometime around the year 66,270.
4.
The Last Total Solar Eclipse
We live in a very odd time.
Not only is there a civilization and intelligence on this world, but we’re also oddly lucky
that we have a moon and sun where their apparent diameters can sometimes be almost identical,
allowing for full total solar eclipses on the surface of this world.
This is probably unusual for most civilizations, since if the moon were any closer or any further
away the sizes as we see them wouldn’t match.
You’d either have ån oversized eclipse, or an undersized or annular eclipse.
To see a perfect eclipse is probably a rare thing for any observer in the universe.
In the future however, there will be a time when all solar eclipses visible from earth
will be annular in nature.
This is because the moon is very slowly distancing itself from earth at about four centimeters
each year.
In fact, when the sun goes red giant, the moon’s orbit will be something around 40
percent wider than it currently is.
As to when the total solar eclipses will end, the last of them will happen about 600 million
years in the future.
But, by that time, if we’re still around, we’ll probably have colonized the solar
system and space, and if you’re in space, then positioning your spacecraft or habitat
to experience artificial total solar eclipses would be in the cards.
3.
Tidal Locking and the Death of the Moon
One thing we commonly hear about small sun-like stars like Red Dwarfs is that the habitable
zone exoplanets orbiting them are probably tidally locked, in that they show only one
face towards their star, much like the moon does with earth.
This is the case for the famous Trappist 1 planetary system, where members are so close
in to their star that they are tidally locked.
What’s surprising here is that there is actually a chance for Earth to become tidally
locked to the sun.
But not yet, the chance comes in about 7.5 billion years during the sun’s red giant
expansion, there is a chance that earth and Mars might become tidally locked to the sun.
This is long after all life on earth will be gone, and this state of affairs won’t
last long if earth is finally swallowed up by the sun, though it’s still unclear whether
it will get swallowed or not due to uncertainties of just how far the sun will expand.
If however Earth and the moon survive the red giant phase, in about 65 billion years,
the moon’s orbit will have decayed, the opposite of its early distancing from earth,
and may actually collide with earth in a spectacular far future impact.
2.
The Helium Flash
The final stages of the sun’s red giant phase are strange.
As its layers expand outward, it’s core will contract and begin to form a white dwarf.
But there is a very sudden, and strange effect that’s thought to occur.
A helium flash.
As the sun reaches its full potential as a red giant, it’s core will heat up, and the
pressure will rise under the contraction of the core, this gets so great that at about
100 million degrees, helium begins to fuse and form carbon.
The circumstances of the core will make helium fuse much faster than it normally would, causing
a somewhat large percentage of the helium core to fuse in only a few minutes.
This is the helium flash, and in those few minutes, the sun’s core will be on the level
of all of the combined luminosity of all stars in the galaxy.
But you wouldn’t see it, the conditions of the core will be such that no energy actually
escapes, so the red giant would remain unphased.
For a time, as the helium flash is the death knell for the red giant phase of the sun.
The aftermath results in core cooling and lower pressure in the shell of fusing hydrogen
around the core, causing a catastrophic drop in output.
In a relatively short period, perhaps something around ten millennia, the diameter of the
red giant shrinks, as does its luminosity, until it's just a few percent of what it was.
The result is a period where the sun will be an orangish subgiant star, and then eventually
a red giant again, but then to the planetary nebula stage and the evolution of the sun
into a white dwarf.
Number 1.
The Death of Planet Earth
Before the sun reaches its white dwarf phase, it will reach a maximum red giant radius of
something around 256 times what it is today.
This is almost certainly the end of Mercury and Venus, though there is a chance for Mercury
to get ejected from the solar system entirely in the meantime, or a very small chance it
may hit Venus in the carnage of the end of the solar system as we currently know it.
Earth and the moon however are a toss up.
It seems most likely that they will be destroyed at this time as well, but that has been debated
and they may simply be scorched and left cinder worlds compared to what they once were.
The actual destruction of earth during this period will be by falling into the sun.
Whether it is destroyed, or turned into a molten ball is irrelevant, by this time almost
all traces of this world once hosting life will be gone.
The only chance would be interstellar panspermia, if that is indeed possible, spreading earth
life to some passing star system earlier in the history of earth, or perhaps it’s already
happened in one of the many stellar encounters our system has had in the past.
Otherwise, a few traces of human civilization may be recognizable through the technology
we’ve sent into space, but even then, at this point in the far future all traces of
that may be gone.
If we’ve colonized other star systems by this point, we too, will be survivors but
most evidence of our origin on earth may be long forgotten or lost.
Barring that, in the far future of the solar system, it will be as though we never existed
at all.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently pondering what a
galaxy spanning youtube is going to look like in 7.9 billion years.
Something tells me there will be cat videos, but instead it will be Glorkon The Absolutely
Gorgeous showing off his pet Slar to the galaxy's collective amusement.
Especially when it playfully eats a multi-billion year old youtuber science fiction author.
Not looking forward to that 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.