From what it is, to when it was discovered, to just how it was made and whether there
are others like it.
Join me as explore how a galaxy is surprisingly inside another galaxy!
Let's think about space for a minute, ok?
You know that there levels to the scope of space, right?
For example, we live on planet Earth, which is part of a solar system that circles around
a sun, and if you go out further, you'll have interstellar space that fills up the Milky
Way Galaxy that we reside in.
Go even further than that and you'll find a multitude of galaxies that make up the known
universe.
There's a lot of levels when it comes to space.
Zooming back into the galaxies level, when you think of galaxies you think of them in
the singular context.
Meaning that every galaxy is one thing, one large galaxy comprised of many objects, but
still, one galaxy.
This all changed though when it came to Hoag's Object.
Which was a literal galaxy...inside of a galaxy.
But we're getting a little ahead of ourselves here.
Rewind back to 1950, and astronomer Arthur Hoag discovered something he didn't expect.
A ring shaped galaxy deep in space.
Further measurements of this galaxy noted that it was an astounding 127,000 light years
across.
But what set apart Hoag's Object from all of the other galaxies in the universe is that
it is part of the .1% of galaxies that are shaped like a perfect ring.
Most galaxies are spiral-like in nature, including the Milky Way and the Andromeda Galaxy.
But not Hoag's Object.
Not only is in ring shaped, but its center is filled with "old stars" that make it look
like something much more.
Which is kind of the point we're getting to.
Because when Hoag, and others, studied this ring galaxy, they figured out that there was
indeed a galaxy within a galaxy.
Which shouldn't have been possible by the very nature of how galaxies work (more on
that later) but there it was.
A galaxy both outer and inner.
And yet, when further examination, there is a THIRD Ring Galaxy within the structure.
So here we have a nesting doll of galaxies that continues to boggle the mind of those
who look upon it.
And honestly, we're a bit weirded out by it too.
Before we dive into how such a thing can exist, be sure to like or dislike the video so we
can continue to improve and make the best videos possible for you the viewer!
Also, be sure to subscribe to the channel so that you don't miss ANY of our weekly videos.
Alright, so let's dive into it right away.
What could have caused not one or two, but THREE galaxies to merge together in such a
way that it creates this very unique effect via the Ring-Shaped Galaxy?
Well, as with much science, there is a lot of speculation and theory, but no hard proof.
But we'll let you know some of the prevailing theories, ok?
The first theory surmises that what happened here was a cause of right timing and placement.
There once was one galaxy.
More than likely a regularly shaped one of average galaxy size (and galaxies are huge
just so we're clear).
Then, one day a rogue galaxy (meaning one that doesn't have a tether) or another galaxy
that was just in the area decided to move through the space where our first galaxy resided.
Usually, when something like this happens we get a collision and cannibal effect (more
on that later) where one galaxy devours the other.
But in this case, because of the distance, the second galaxy just hovered there for a
while, causing all sorts of chain reactions, and then flew back out into space.
When it did this, the gravity from the first galaxy took some of the stars and items from
the second galaxy.
When it did this the "new stars" took up space in the first galaxy, but because of various
galactic forces were forced away from the core.
Which is where the ring came to be.
And thus the core of the ringed galaxy is its own galaxy, while the ring is also a galaxy,
and the third galaxy is the space in between.
You might think that this is something rather complicated, and it is, but weirder and more
random things have happened in space, so there is merit to this.
However, given the laws of probability, and further research on this ring galaxy, there
is some flaws to this theory.
First and foremost, as far as we can tell...this galaxy has never had a collision with anything
else, even a slightly one.
Furthermore, the rogue or fast-moving galaxy would've needed to hit the right spot in order
to cause the chain reaction that the theory states made the ring.
Not impossible...but very improbably.
I mean we're talking a billion-to-one shot if not more.
That's not the kind of odds scientists like to bank on when trying to explain something.
Theory #2 is one we've alluded to before, and that's the concept of galactic collision.
On a cosmic scale, it might seem hard to think that galaxies would actually collide with
one another, especially when you consider that galaxies aren't a singular object, but
a collection or millions, or even billions of tinier objects.
All of which are caught within the gravity of certain massive objects.
So how exactly does a galaxy "collide" with another?
Well to be fair, it's not your typical type of "collision".
Because when you think about a collision, you're likely thinking about a car crash,
or you're thinking about two people running into each other, you think of a physical confrontation
that leaves both sides wounded in the aftermath, which is fine!
But that's not exactly what's going on here with these galaxies.
When two galaxies "collide", it's more about them getting so close to one another that
their gravities start to fight one another.
It can get physical, but not in the sense of planets running into one another, or stars
absorbing one another, that kind of thing.
It technically can happen that way, but it's an extreme rarity.
Rather, what usually happens (based on how we've observed the universe, including seeing
some smaller galaxies colliding) is that there is a bigger galaxy, and a smaller galaxy,
and over time, they drift closer and closer to one another.
Eventually, the gravities of one of them reach the other, and when that happens the "collision"
begins.
Usually by the larger galaxy ripping apart what is on the edge of the smaller galaxy.
They'll move closer and closer together, entities like planets, moons, stars and more will be
ripped from their orbits and find themselves getting "settled" in the newer galaxy.
At times, the force of the opposing orbits will force planets or stars to actually be
THROWN out of the galaxy itself, becoming a wondering entity among the stars.
Other times the placement of things like black holes will devour certain things in the young
galaxy depending on their position.
Needless to say, it's a rather violent affair.
To the extent that when all is said and done, there is typically only one galaxy remaining,
and that galaxy is much bigger and full of entities than it was before.
It's not quick, but it is all-consuming...usually.
Because as theory No.2 about Hoag's object states, what could've happened was two satellite
galaxies couldn't merged in such a way that they created the inner galaxy object and the
outer galaxy object.
A perfect fusion with a unique shape.
Possible?
Yes.
Likely?
Unclear.
One of the biggest deterrents in this theory is the lack of "tails".
As noted, most galaxies have a spiral shape.
And when galaxies collide, they usually leave traces of the scattered remains of the collision
in the form of "tidal tails".
Remnants that drag behind the galaxy like a tail of a dog and even grow to astounding
size.
Yet when you look at Hoag's object...they're not there.
It's perfectly round and not a tail in sight.
This can be explain by time depending on how old the galaxy is.
Mainly, over the course of time the tails disintegrated or moved on somehow, and thus,
the perfect ring shaped galaxy remains.
A third major theory states that the answer lies in the type of galaxy this object was
originally.
Mainly, a "Barred Spiral Galaxy", where the contents are not rooted in cores gravity,
but in the shape of the galaxy itself via its structure.
Then, over the course of time, this "bar" broke and that left to flailing arms of the
galaxy around the dense core.
These arms would eventually curve and would become the ring we see now.
The problem with this particular theory though is that for this to have been a barred spiral
galaxy, its core would need to be flat...except it's convex.
Furthermore, that wouldn't explain all of the different colorings that can be found
in Hoag's object.
So this theory is a bit of complicated one like the others.
So what is the answer?
Which of these theories, or combinations of them, is the truth as to what Hoag's object
is, and isn't?
In truth...we honestly don't know.
But that's not to say that people aren't trying to figure it out, especially with the potential
of a third galaxy being inside of Hoag's object and all that.
Some even think by studying Hoag's Object at an atomic level that the answer can be
revealed.
But whether that is truly the case remains to be seen.
After hearing all this stuff about nesting doll galaxies, you might wonder if there are
other instances of this out there in space.
In terms of galaxies, it's possible, we just haven't found them yet.
But in terms of the other "levels" of space, you'd be surprised.
For example, in space there is a star was known as Kepler 70.
This was very much your "typical" star, in fact it's been noted that it was at one time
very much like our own sun in our solar system.
Then, as its life went on, it transformed itself into a Red Giant.
Very standard fair for stars.
But then, when it lived out its cycle as a red giant and dropped its shell, scientists
were in for a shock.
Because when it did, it was discovered that two planets had been within the shell and
going about life like nothing had happened for some time.
Kepler 70b and Kepler 70c were even Earth-like in some aspects, while others compared their
composition to the core of the planet Jupiter.
Either way, the fact that a planet could live in a red giant like that is mind-boggling
to say the least.
Especially since the heat would scorched most planets to ask, but not with these ones.
Another example of this kind of nest doll-like inception can be found in the Microscopium
constellation.
There, an exoplanet was found to be WAY too close to the star it was orbiting, and there
was no logical reason for that to be happening.
Scientists believe that it was at one time orbiting the star when it was in its red giant
phase, and then when that ended its orbit was rocked and thus it moved much closer to
the star.
And yet, others think that for some reason, the planet just has that natural orbit, and
thus when the star reaches its red giant phase, it'll be obliterated.
While planets inside of stars is rare (but proven), something that theoretically happens
a lot more is the concept of having stars inside of stars.
Such a theory was put forth in 1975 when two scientists stated that Neutron Stars could
collide and be absorbed by red giants.
For the longest time this was nothing but a theory, and then, in 2014, HV 2112 was discovered,
and it was revealed to truly be a star inside of another star...or at least, that's what
some believe.
There is some debate going on in this matter.
Then, if you look at the grander levels, you'll see nesting dolls in the simplest of things,
including the comets and meteors and asteroids that fill up space in many levels.
A fragment of debris that was found in the South Pole on Earth was discovered to have
the core of a comet.
You don't usually have comets falling to Earth as they usually just rocket through space
(including Halley's Comet).
But this one was revealed to have collided with an asteroid and got consumed by it, and
then when that asteroid cracked away as it entered the Earth's atmosphere, it released
the core of the comet, giving scientists quite a rare find.
So as you can see, space has a lot of these nesting doll type entities, and they can go
from the most basic of rock formations to the grandest of galaxies.
And if you think about it, even Earth is a nesting doll because of all the layers that
comprise the core and surfaces of the planet.
It's all very trippy when you think about it.
And this is yet another reason why people love to explore space, they want to find these
rare things like Hoag's Object and go and see what makes it work, if they can even theorize
how things like it came to be.
Space is full of mysteries like this and we want to solve them, and that's what drive
most of to find out everything we can about the universe.
Thanks for watching everyone!
What did you think of this look at the mystery of Hoag's Object and what it means to have
a galaxy inside of a galaxy?
Does this change the way you think about space?
Do you think there are some more rare marvels like this out there in the universe?
Let me know in the comments below, be sure to subscribe, and I'll see you next time on
the channel!