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 universe in which we live.
