Black holes have been a big hit in movies and tv shows for the past several decades.
They have been used to teleport characters through space and time. In different forms of art,
black holes have represented an unknown that can be used to accomplish seemingly impossible tasks.
But until recently, no black holes have been found that could be considered
close to Earth. That all changed once astronomers detected a black
hole that is close enough for it to be considered at our cosmic doorstep.
As a species we are getting closer to unraveling the mysteries of our universe
and black holes may be one of the mysteries we are able to wrap our heads around first.
When a star larger than our sun reaches the end of its life,
a black hole is born in its dying breaths. A star with a LARGE enough mass will eventually collapse
in on itself when it can no longer perform nuclear fusion in its core.
The mass of the will begin to fall in on itself and form an INCREDIBLY dense ball of matter.
This newly formed black hole will begin to draw in
anything around it with its immense gravitational pull.
Their pull is so large that not even LIGHT can escape from it if it gets close enough.
As they draw in more matter the mass of the black hole increases. Some of the largest black holes,
called super massive black holes, sit at the center of galaxies keeping them held together.
Black holes can range in size a lot with the smaller ones measuring ten times the mass of
our sun to the biggest ones measuring in at over a BILLION times the mass of our sun.
Black holes were first predicted in Einstein’s theory of General Relativity and were considered
science fiction until one was finally detected in nineteen seventy one. Since then
astronomers have gotten better at finding them by refining their methods.
Most black holes that scientists have found were detected using x-rays. When a black hole
takes in matter, the matter swirls in towards the black hole. As it is swirling around,
friction causes the matter to heat up to extreme temperatures and begin giving off
x-rays. When we detect this type of x-rays in space we know that we’ve found a black hole.
More recently physicists at the Laser Interferometer Gravitational-Wave Observatory, or
LIGO, have been able to detect the gravitational waves produced by the collision of two black holes
using advanced laser technology. As the black holes collided, they created what is called a
gravitational wave that rippled outwards in all directions. The lasers at LIGO are built to pick
up these small gravitational waves and may give us the ability to locate newly formed black holes.
Detecting black holes not only gives us more information about them,
but it also gives us a better idea of WHERE black holes are,
HOW they are formed, and IF they will pose a risk to us on Earth.
In recent months astronomers have discovered a black hole that is closer to Earth than ANY
other known black hole. It is only fifteen hundred light years away from Earth which
may seem like far away but in the scale of the cosmos it is essentially right next door to us.
Scientists discovered this black hole by studying the gravitational effects acting on the two stars.
These two stars were observed to be moving in orbit around each other taking odd paths.
When scientists started looking closer at the movement of these two stars they came to
the conclusion that there MUST be a third object causing the stars to orbit in the way they were.
They began looking closer at the exact movements
and still could not see any third object in between the two stars. After enough study,
the astronomers came to the conclusion that the only object that could cause
these gravitational forces while evading direct detection must be a black hole.
This black hole is far away enough from earth that it does pose a direct danger to us. But
this system of two stars and a black hole is still considered close to us on a cosmic scale.
This discovery of a black hole this close to Earth showed scientists black holes
close to us may not be as uncommon of an occurrence as once believed.
Discovering this one on our cosmic doorstep after five decades of looking for them in the cosmos
proves that black holes can hide themselves well and that
astronomers have many more black holes to find within our galaxy and beyond.
While the newly discovered black hole is close, it is also staying put within its system.
But not ALL black holes stay where they are, there are ones that
travel through the cosmos freely. These types of black holes are called ROGUE black holes.
Astronomers theorize that black holes can be ejected from the
galaxy it is at the center of sending them off on their own.
These black holes can fly through space destroying any bit of matter that gets close enough to it.
While flying through space they are moving at extreme speeds, astronomers have clocked
a rogue black hole traveling at speeds almost five hundred MILLION miles an hour. A black
hole moving at this speed will be able to move through our solar system extremely quickly.
At this speed, traveling from Earth to Mars would only take seven hours.
Astronomers believe that there may be at least
twelve of these rogue black holes within the Milky Way.
If scientists find a way to detect these rogue black holes effectively
it will mean that we can look for them and have a warning before one gets too close to Earth.
Unfortunately, there is no real way scientists can reliably detect a rogue black hole.
Most black holes have been found by detecting the x-rays emitted from
matter as it swirls into the black hole.
But because rogue black holes are flying through empty space,
they are not currently feeding on matter making the method of x-ray detection impossible.
Unfortunately the most advanced instruments that astronomers use to observe the universe
rely on some form of LIGHT; radio waves, x-rays, or visible light. This means
that they are next to useless if we are trying to look for a black hole directly.
We still have a chance at detecting one using our current instruments by looking for its
gravitational influence on other matter. But in order to detect it using its gravitational
influence it needs to be close enough to a celestial body that it causes a strong enough
pull. And we will need to be looking in that general direction to see that when it happens.
We may not know if a rogue black hole is coming towards us
but we will see the effects of it as it crashes through the solar system.
A rogue black hole would fly through, drawing in anything and everything that it touches. Our
planet would meet the same fate as all the other planets in our solar system along with our sun.
Because we would not be able to see the black hole with our eyes,
as it enters the solar system we would expect to see our neighboring planets
disappearing from our sky after being drawn into the body of the black hole.
But in order for this to occur, we would have to be INCREDIBLY unlucky.
The chances of this happening are extremely low
so scientists are not too worried about a rogue black hole traveling into our solar system.
There are plenty of scary things in the universe
but black holes may be one of the most destructive and most mysterious objects that we know exists.
It wasn’t until the last few decades that black holes were known to exist
and only in the past twenty years have astronomers begun to really
uncover what black holes can tell them about the universe.
Even with the closest black hole being fifteen hundred light years away, its existence shows
us that black holes can easily hide from our instruments until we really take a moment to look.
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