While decades of solar system exploration has answered many of humanity’s questions
about the nature and formation of this star system, with in depth study comes even more
mysteries and odd possibilities.
Some of them are intriguing and strange, and some of them are outright unsettling.
So here are ten of the most unsetling Solar System possibilities.
Number 10.
The Solar System Can and Probably Has Ejected Planets.
Long ago in prehistory humans noticed that certain objects among the stars in the sky
moved, so strangely in fact that these objects, the planets, still bear ancient names of gods
and goddesses.
Today we can very accurately predict the orbits of the planets as they move in a kind of clockwork
precision as they do their gravitational dance with the sun.
This was not always so.
Early in the history of the solar system gravitational chaos reigned as opposed to clockwork like
precision.
Planets like Jupiter migrated creating the chaos.
But during this period of instability, it’s possible that planets within our solar system
were ejected entirely from it.
One potential indicator for this is the lack of a certain type of planet that seem very
common everywhere else in the galaxy, but not here.
These are the so-called super earths, planets significantly more massive than our world
but not as big as Uranus or Neptune, and our solar system seems rather odd for not having
one.
It’s possible that it once did, and our solar system’s super earth was ejected early
in the history of the solar system.
That said, as the solar system ages, chaos will come again.
While the fate of earth and venus are likely to involve getting engulfed by the sun rather
than ejected, there is a chance, though it’s thought to be quite low, that in the far future
the planet Mercury will be ejected from the solar system as it goes through further changes
as it ages.
Number 9.
Planets Can and Do Go Horribly Wrong
While the solar system itself changes over long periods of time, the individual planets
do as well.
While some aspects of them change every day, they also change long term and a planet can
start out one way, and then end up presenting completely different conditions over time.
Three of the inner planets in our solar system have done this.
Earth, Mars and Venus.
They all started out looking somewhat similar, possibly all three having had liquid water
on their surfaces at one point.
But, over time these worlds were subject to circumstances that changed them dramatically.
In the case of Venus, it was a runaway greenhouse effect due ultimately to being located just
a bit too close to the sun.
As Venus’ liquid water evaporated, the insulating effect of water vapor retained heat, warming
that planet up.
Further still, as this transformation occurred, it led to the formation of the thick carbon
dioxide atmosphere and the extremely hot temperatures we see today on that world.
For Mars, it was a different effect.
It simply couldn’t hold onto its atmosphere, losing it to the solar wind and radiation,
dropping its temperatures below those needed for surface liquid water.
With earth, it was life that changed it.
Earth has seen several phases of atmospheric composition, but the defining event in the
creation of the oxygen rich atmosphere we know today was the evolution of photosynthesizing
plants.
Number 8.
There Very Well could be Undiscovered Planets
The outer solar system presents a growing mystery.
The motion of a growing number of objects in the outer solar system appears have been
affected by something much larger than a typical Kuiper Belt object.
Rather it suggests the existence of a very large unseen ninth planet lurking in the outer
solar system, likely very distant from the sun, but still in orbit of it.
If this planet exists, it’s likely to be discovered sometime in the next few years
through one of several sky surveys, and in particular the Large Synoptic Survey Telescope,
which when it comes online is specifically designed to pick up moving objects, such as
planet nine.
The existence of this planet might also solve the solar system’s missing super earth conundrum,
if it existed.
That it wasn’t ejected completely, rather just thrown into the outer solar system.
Or, it may be the case that planet nine isn’t originally from this solar system at all,
and was captured by the sun at some point, in which case a truly alien world might await
us to explore far out in the outer solar system.
And if one unknown planet isn’t enough, some evidence exists that there may be more
than one, and that a tenth planet may also lurk distantly from the sun.
Number 7.
The Sun is Growing Brighter
The sun is by far not a static object.
Over short and long periods of time, it changes.
One of those changes, luminosity, will result in a brighter sun that will bake the earth
far earlier than during the sun’s great change into a red giant billions of years
from now.
The initial problem with this won’t simply be hotter temperatures, rather its effects
on earth’s geology will cause a decrease in carbon dioxide levels, roughly 600 million
years from now.
These levels will fall below what some plants like trees can handle with photosynthesis,
but other plants will persist longer.
Eventually, however, all plant life on earth will be overwhelmed, and with that all animal
life.
By 1 billion years from now, the oceans will evaporate, causing a runaway greenhouse effect,
that, over time will cause the temperatures to continue to rise and destroy any remaining
microbial life on this world.
Providing we don’t do anything about it in the far future, eventually Earth will someday
have no life at all.
Number 6.
Total Solar Eclipses
To understand just how unsettling this particular phenomenon is, you need to experience eclipse
totality, where the sun is entirely blocked by the moon passing in front of it.
Seeing a partial or annular eclipse does not do this justice, nor does photography, and
having seen totality during an eclipse myself, I instantly realized why ancient peoples often
found these a bit disturbing.
But, mostly, they didn’t really understand what was causing them.
Now, we do know, it’s the moon occasionally passing in front of the sun.
The thing is, it really shouldn’t do that, at least the way it does it.
By total chance, the apparent size of the moon as we see it happens to be almost exactly
the same size as the sun, as we see it, allowing for a total solar eclipse so precise that
we can observe the sun’s corona in its full glory from the surface of the earth.
This is a bit weird.
It does happen one other place in the solar system; Jupiter’s moon Callisto has that
effect at Jupiter.
But this phenomenon on a habitable world in the universe doesn’t seem like it would
be very common, and there’s no reason why it happens to be that way.
It just is, and just happens to occur this way at the exact time that there’s a civilization
around to see it.
But if the galaxy is full of alien civilizations, it may be that our planet ends up as a tourist
destination for extraterrestrial eclipse viewers.
At least for a time anyway, about 600 million years from now Earth will experience its last
one, after that, the moon will have drifted far enough away that it will no longer completely
block out the sun.
Number 5.
The Solar System is not Isolated.
It’s been said that we live in a cosmic shooting gallery.
Comets from the outer solar system regularly pass by, and so do asteroids, and in the past
those objects have hit earth, and will again unless we deflect them.
This used to be far worse, to the point of bombardment in the early solar system, but
it’s calmed down as the solar system has settled down.
But with the recent confirmation of the first interstellar object we’ve ever observed,
Oumuamua, it’s driven home that we’re not just under bombardment from objects originating
within our solar system, but also objects originating from the rest of the galaxy.
And this will never stop, flotsam and various rocks probably pass through this star system
constantly, and will for as long as earth exists.
But that’s not the only thing that can pass through.
Biology is part of our universe as well, and whether common or rare, our planet proves
this.
Our planet also proves that intelligent life is possible in this universe, again, rare
or not.
If other intelligent life exists in the Milky Way, and is reasonably close, there has been
enough time since the formation of the galaxy for other civilizations to have plausibly
arisen and become highly advanced.
Given the immensity of geologic time, such a civilization might have existed in this
galaxy for a very long time, billions of years potentially, even at sub-light speeds they
could have had plenty of time to send a probe here.
We’ve never seen anything that unequivocally says they have, but it is possible that this
solar system has been visited.
Number 4.
The Sun Can At Any Time Disrupt Civilization
While long-term, the sun will eventually destroy earth, first by baking its surface and then
eventually engulfing it as the sun becomes a red giant.
But the sun also presents a short term threat, that of a coronal mass ejection.
While coronal mass ejections are nothing new, the earth has been bathed in them many times
over its history and life itself weathers them just fine, human technology is new and
is highly vulnerable to such storms.
In 1859 for example, earth was lined up in the sites of such a solar storm and it resulted
in massive auroras and disruptions to the telegraph system that was in place at the
time.
If, or perhaps when, this happens again it would cause widespread damage to our technology,
to the tune of trillions of dollars.
In 2012, a coronal mass ejection of the size of the 1859 storm occurred, but luckily missed
earth.
One of these days, we won’t be so lucky.
Number 3.
There Could Very Well be Undiscovered Star Systems Nearby
We tend to think of our nearby stellar neighborhood as known territory, where Proxima Centauri
is the closest star, followed by the other members of the Alpha Centauri system.
But in reality, there is a mystery about the density of the local group of stars.
As far as dwarf stars go, this density is lower than expected leading astronomers to
suspect that there are perhaps many undiscovered stars within 20 light years of earth.
This is not as surprising as it may seem.
Red dwarfs just above the limit from a brown dwarf emit most of their radiation in the
infrared, and are quite dim in visible light.
Yet, red dwarves are the most common type of star in the galaxy.
It’s entirely possible that we simply haven’t noticed all of the nearby ones yet, and in
fact a red dwarf known as Teegarten’s star was only discovered in 2003, despite being
only 12 light years from earth.
Close stars can be a problem.
The star Gliese 710 is expected to pass by the solar system in a bit over a million years
and possibly pass close enough to us to disturb the Oort cloud and potentially send a hail
of comets into the inner solar system that could pose a threat to earth.
We know about that star, but there may be others that could pass by that we currently
have no idea exist.
Number Two.
Venus’ Odd Clouds and The Possibility of Extreme life.
Perhaps the greatest mystery of the planet venus is not on its surface, that is a high
pressure, high heat hellish wasteland, but instead its atmosphere.
Within the upper reaches of Venus’ atmosphere is the most earth-like place in the solar
system, even above the environments of Mars.
This zone has cooler temperatures and pressures, comparable to earth.
And while that atmosphere is unbreathable, it’s actually easily survivable for a human
who might experience a tear in their spacesuit if they were in those conditions.
Given that this clement zone exists, and that Venus in the past was much more earth-like
than it is now and in fact may once have had liquid water, it’s possible that life might
have arose there long ago.
If Venus’s transition to a hell planet was slow, that life might have adapted to survive
in this clement zone in the atmosphere, providing that it adapted to the high sulfuric acid
environment and evolved some way to protect itself from increased ultraviolet radiation.
Or it may use that ultraviolet light as an energy source.
That would explain another of Venus’ mysteries.
Unexplained dark areas appear in ultraviolet images of Venus’ cloud tops.
UV absorbing microbial life might provide an explanation.
Number One.
Did Life Originate on an Asteroid?
There are many questions about origins of life on earth, and how it might relate to
the solar system at large.
There is the possibility that simple life on earth did not originate here, rather it
might have originally arose on Mars and was transported here via panspermia.
But Mars isn’t the only option.
It’s possible that it might not have originated on either a planet or a moon at all, instead
it may have arisen on the asteroid Ceres, though it’s really more of a dwarf planet.
This asteroid seems to have the right mix for life and may have once, or still does,
harbor a subsurface liquid ocean.
Also, organics have been detected, raising the possibility for life on this asteroid.
But, there’s more.
Early in earth’s history, during the late heavy bombardment, life on earth was unlikely
due to the pummeling this planet was taking at the time.
But there is evidence that Ceres somehow avoided impacts during this period, in that the water
mantle present on the asteroid would have been blown off, as is the case with other
asteroids in the solar system, and it wouldn’t have had the gravity to recapture it.
This is particularly interesting because while it’s possible for rocks to be blasted off
Venus or Mars to land on earth, and conceivably carry live microbes with it, the lower gravity
of Ceres should allow for materials to be blasted off during small impacts much more
straightforwardly, presumably making panspermia from this object easier.
Unfortunately, no evidence for this exists, it’s merely speculation, and in fact no
meteorite has ever been found that can be identified as being from Ceres.
But it’s an interesting thought that earth may not technically be our homeworld, and
that the origins of life on earth might have began at the minor planet Ceres.
Thanks for listening!
I am futurist and science fiction author John Michael Godier 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
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