Given that we know the universe is infinite, it should come as no surprise that the things
we’ve found beyond our planet tend to be a bit bizarre.
But the really surprising thing is that every time scientists think they’ve figured something
out, they discover something new–and in some cases, more than a little troubling–that
disrupts the theories they spent so long developing and proving.
It may come as a surprise, considering how intensely we look out onto the stars, that
even in our own backyard there are things scientists just don’t understand.
10.
Why and How is Space So Noisy?
“In space no one can hear you scream,” goes the famous tagline to one of the all-time
hits of science fiction horror, Alien.
However, scientists have discovered that contrary to the commonly-held belief, space is incredibly
noisy.
The problem is that they’re not sure why.
Especially concerning is what scientists have referred to as “space roar,” comprised
of odd, extremely loud radio signals bouncing around all over the place, along with some
other signals that scientists just can’t explain.
The discovery came in 2006, when a NASA balloon mission with the intention of catching faint
radio waves indicating stars formed early in the history of the universe instead caught
a loud blast of noise.
Theories for what is causing the constant noise include a lot of options from the very
radiation the mission was trying to detect to gas swirls and even the noise of galaxies
themselves, but so far none of those theories adds up.
9.
The Great Attractor
Some 220 million light years away, something is pulling our galaxy towards itself.
What is it?
Scientists don’t really know–because they haven’t been able to actually see the object–or
objects–causing the reaction.
The Great Attractor is what the gravitational anomaly has been called, and most of our knowledge
of it is indirect, including the theories about why we don’t know more.
The Great Attractor was first discovered in the 1970s, in the sector of the sky that scientists
have named “the Zone of Avoidance.”
For decades, scientists avoided looking there because–being in the same direction as the
center of our galaxy–it’s full of gas and dust and other debris, making it harder
for earlier-generation instruments to pick out anything in particular among the noise.
But that discovery showed us that the Milky Way galaxy, along with several others in our
local group, are definitely being pulled towards something.
More recent astronomical technology has allowed us to look more closely into the Zone of Avoidance,
enough to see a large supercluster of galaxies near The Great Attractor called the Norma
Cluster.
However, even as big as the Norma Cluster is, scientists have already ruled it out as
a candidate for The Great Attractor.
Fortunately, scientists are fairly certain that this particular anomaly isn’t going
to destroy our galaxy any time soon, considering the much more immediate and closer-to-home
threats that are out there.
8.
Giant Voids
How can there be a void within a void?
Space is generally considered the ultimate void: after all, normal matter only makes
up between 1 and 10% of the known universe, so automatically, the rest should be void.
But it turns out that some parts of space are just a little too empty, a little too
underpopulated.
Voids come in varying sizes, and generally are discovered via “cold spots” in the
map of cosmic microwave background (CMB) charted by astronomers across the known universe.
Little pockets of nothing are not that strange, but big pockets of the known universe where
there are few if any stars are another thing entirely.
The largest void theorized to exist is actually very close: the KBC void, also known as the
local hole, is theorized to house the Milky Way galaxy, along with our local cluster.
If the observations of the scientists it’s named after (Ryan Keenan, Amy Barger, and
Lennox Cowie) are correct, our galaxy is in a hole that may be anywhere from 1 to 2 billion
light-years across, situated a few hundred million lightyears away from the center.
The Boötes void, discovered in the 1980s, is approximately 250 million lightyears across,
seems to have only about 60 galaxies in it.
For comparison, our own galaxy (which as noted before is in its own rather large hole) has
over two dozen galactic neighbors.
Why are these patches of nothing important?
For one thing: they challenge our existing ideas of the formation of the universe and
just how old our universe is.
Even the billions of years we know the universe hasn’t existed shouldn’t have been long
enough for regular spreading to create giant holes of nothing.
Which leads to the other reason: the voids could, some scientists theorize, be created
by surges of dark energy.
Ultimately, however, nobody knows why the universe seems to be dotted with these random,
enormous holes with little to nothing visibly going on in them.
7.
Saturn’s Moons
While the broader area of space beyond our backyard is full of mysteries, it’s a common
assumption that we have a pretty good handle on what’s going on in our own solar system.
Which makes it strange indeed that we recently discovered a brand-new moon circling Saturn.
“Peggy,” as the tiny, possibly disintegrating satellite is called, was discovered in 2013,
when NASA’s Cassini snapped a picture of Saturn’s rings, and caught disturbances
that suggested the formation of a new moon.
The discovery did shed light on how Saturn has managed to acquire so many moons–62
confirmed, with 150 satellite objects of different sizes–but it also opened up more questions,
including how stable the moons of Saturn truly are.
Since Cassini went dark in 2017, there’s no real way of knowing if Peggy is even still
present; JPL speculated that the diminutive moon was unlikely to get any bigger, and in
fact was much likelier to disintegrate.
It’ll be some time before another mission can make it to the ringed planet, in order
to get close enough to confirm or deny.
6.
Something is blocking us from seeing the light from a faraway star
A star approximately 1,500 light years away from us, unofficially named “Tabby’s Star”
or KIC 8462852, is notable for having another, much less formal nickname: “WTF star.”
In this instance, WTF stands for two different acronyms, the more polite one being “where’s
the flux?”
That’s because something–and to date, scientists aren’t sure what–is blocking
us from seeing approximately 20% of the light from the star.
Theories on what could be blocking the light range wildly: Tabetha Boyajian, who the star
is named for, speculated that it could be a Dyson Swarm, a theoretical megastructure
proposed to be used by advanced civilizations to harvest energy output from a star.
Of course, this explanation hasn’t sat well with anyone, and from the time Boyajian announced
her findings of the star’s odd pattern of dimming in 2013, various scientists have sought
to explain the variability and dimness, with the most recent papers published in 2019.
However, to date, nothing has fully explained why the star is being blocked.
5.
New Black Hole Discoveries Continue to Prove We Don’t Know Black Holes That Well
Now that scientists have captured the first image of a black hole, the odd phenomenon
seems almost mundane in comparison to how scientists and laypeople alike used to consider
them: just another stage of stellar evolution, and what happens to very large stars when
they burn out.
However, just as scientists have begun thinking that they understand the fundamentals of the
phenomenon, they’ve encountered another curve ball: some of the supermassive black
holes they’ve discovered are just too big and too young to exist, given our understanding
of the age of the universe and how the structures form.
In 2017, scientists discovered one of the biggest, most distant supermassive black holes
to exist: the object formed when the universe was only 5% of its current age, something
that shouldn’t have been able to happen in the first place.
Add to that the sheer mass of the object, and scientists are even more puzzled.
There simply isn’t enough time, according to what scientists know about the age of the
universe, for an object that large to happen.
More recently, Chinese scientists found another monster of a supermassive black hole closer
to home: 13,800 lightyears away from Earth, it’s 68 times heavier than our sun, which
just shouldn’t be possible.
The discoveries just prove that the moment scientists are certain they understand the
mechanics of the mysteries of space, something is certain to come along and throw another
wrench into the theories.
4.
How Many Planets are Actually in Our Solar System?
Everyone learns that there are eight (or, prior to 2006, nine) planets in our solar
system; there are even multiple mnemonic devices for remembering the names in the right order.
But more recently, models following the movement of objects in our solar system have indicated
that that fundamental understanding might be entirely wrong.
In 2005, astronomer Mike Brown of Caltech discovered an object larger than Pluto in
the Kuiper Belt, which itself triggered a scientific revolution: since there were objects
larger than Pluto beyond its orbit, the then-ninth planet was demoted to “dwarf-planet” status
by the International Astronomical Union.
Fast forward to 2016, and Brown came back with solid evidence of another planet beyond
Pluto, this one the size of Neptune.
The difficulty comes in, however, with just how far away the massive planet is: so distant
that we effectively can’t see it.
In fact, the way Brown and his colleagues discovered the planet is only through looking
at models for the orbits of existing planets and known bodies in our solar system.
As scientists look into how to prove or disprove the planet’s existence, a bigger question
continues to loom: just how big is our solar system, and are there even more planet-sized
objects, even further out, that we just can’t see?
3.
How Do Solar Systems Develop and Evolve?
For decades, the development of our solar system was settled science: rocky planets
like Mercury, Venus, Earth, and Mars formed early on, since the harder materials that
made them up could withstand the intense heat closer to the sun.
Over time, gas giants like Saturn, Jupiter, and Uranus came about from lighter materials–ice,
liquids, gas–that came together in the colder region further away from the sun.
But once again, more recent observations from outside of our solar system have brought that
into question: gas giant planets called “hot Jupiters” and “hot Neptunes” that are
much, much closer to their star open up the question of whether they formed closer to
their sun, or if they migrated there over time.
As scientists seek out exoplanets–that is, planets circling stars outside of our solar
system–the generally accepted theory of how our own celestial neighborhood formed
has met bigger challenges.
Hot Jupiters and hot Neptunes are gas giant planets that orbit close to their stars, in
a few instances as close as 1 AU (that’s the same distance between the Earth and the
Sun).
What scientists can’t agree on is whether the gas giants actually formed so close to
the star they’re orbiting, or whether they’ve been drawn closer and closer over time.
The answer to that question–if it can ever be determined–could tell us a lot about
how our own solar system formed and its ultimate fate: did the giants in our system spread
out over time, or will they be pulled in like a death spiral?
2.
How Did the Universe’s “Dark Age” End?
Space is mostly dark–that’s the accepted understanding, and it’s not exactly wrong
from an observational perspective.
So it may be surprising to know that there was an era in the universe when it was even
darker: a period starting about 300,000 years after the Big Bang and ending approximately
500 million years after the beginning of the universe when gases were so dense that light
wasn’t able to penetrate or travel.
In short, the universe was as dark as it is possible to be, everywhere.
And then, seemingly just as suddenly, that ceased to be the case: all at once, the universe
reionized, and slowly gases began to pull together into structures that we can recognize
now.
But why and how?
Scientists don’t know.
Observations of cosmic microwave background and the areas where we’re able to see the
earliest formation of the universe tell us that it did happen–in fact, we wouldn’t
exist if it hadn’t–but because those areas are still dense with gases, it’s nearly
impossible to observe in such a way to get answers.
Scientists are so perplexed, in fact, that theories on it are fairly thin on the ground:
cosmologists and astronomers and theoretical physicists alike are still bent on trying
to find something to observe from which to start forming theories.
All we know at this point is that approximately 500 million years after the Big Bang, something
metaphorically gave the opaque and neutral universe a shake, and the gases and dusts
began to settle into specific structures that would lead to stars, planets, galaxies, clusters,
and everything else we’ve been able to identify.
1.
What Came Before the Big Bang?
After a great deal of controversy, astronomers and physicists discovered fundamental evidence
of the “Big Bang,” the event that began the universe as we know it.
The question still plaguing scientists, though, is: what was the universe like before the
Big Bang?
Clearly, if something could explode, something was there–but what was it, and how did it
behave, and how did it create such an enormous explosion that the known universe still feels
the effects billions of years later?
Scientists used to think that the universe was timeless: it always existed, it would
continue to exist into infinity.
But the evidence of physics and cosmology alike points conclusively to a set beginning
point.
As things stand right now, we know what happened starting one second after the Big Bang, when
the universe cooled off sufficiently for subatomic particles like protons and neutrons to stick
together.
But we have no way currently to know how the Big Bang itself happened–which means that
there’s no way to say what the universe looked like before it.
The most commonly-accepted theories revolve around a superdense, ultra-hot collection
of material, but scientists in favor of that theory can’t agree whether it was an infinite
stretch, or infinitely tiny.
Other theories include the possibility that the Big Bang wasn’t a one-time event, but
instead a recurring one–though of course, on such a massive scale that life as we know
it will long since be extinct before it recurs.
Some theories even suggest that prior to the Big Bang, there was fundamentally nothing
at all: that the entire universe of matter exploded into existence out of a void.
It’s more likely that we’ll never know than that we’ll ever find out, and the late
Stephen Hawking suggested that the answer isn’t even important: since “before the
Big Bang” is essentially before time, whatever was present can’t be observed, and is ultimately
irrelevant.
But that fact doesn’t stop people from wondering.