People have always been dreaming of conquering
other galaxies and exploring space far away from our home. But the thing is that there are enough enigmas
in our own Milky Way galaxy! Even better, there is one right inside our
Solar System! This mystery is lurking somewhere on the outskirts
of the planetary system, puzzling astronomers to no end. Once upon a time, scientists noticed that
something bizarre and inexplicable was causing chaos out there, in space. A mysterious celestial body was influencing
the orbits of six smaller object in Kuiper Belt, far, far away from our home planet. This something got the name of "Planet Nine"
and a much more offensive nickname "Fatty." Well, no wonder: the thing was 10 times heavier
than Earth! But soon after astronomers started to research
the hypothetical planet, things took an unexpected turn. But before I tell you all about this new development,
let me summarize everything we know about Planet Nine. So, as I've already mentioned, the thing is
massive: more than 10 times bigger than Earth and around 5,000 times as large as Pluto! That's why the planet might have great gravitational
force. It also means that Planet Nine is likely to
be an ice giant. You see, rocky planets, like Mars or Earth,
can't grow bigger than a certain size because they are, well, pieces of rock. If they became as huge as Saturn or Jupiter,
they would turn into ginormous gas giants as well. But ice giants are another matter: they aren't
as massive as gas giants but have a similar atmosphere. And since it seems that Planet Nine doesn't
have the impressive size of a gas giant but is bigger than any rocky planet, there can
be only one conclusion - an ice giant! If "Fatty" does exist, people will most likely
have to rewrite astronomy books! We used to believe that Neptune is the furthest
planet from the Sun. But now, it may turn out that Planet Nine
is the champion, being 20 times further away from the center of the Solar System than Neptune! In other words, it's 56 billion miles away
from the Sun, and NASA's New Horizon Probe would need more than 50 years to reach the
mysterious planet! By the way, the probe got to Pluto after only
9 years of traveling through space. Also, if you lived on Planet Nine, your year
would last 10,000 to 20,000 Earth's years! That's the time "Fatty" needs to orbit the
Sun because of the immense distance between these space objects. And if it's difficult for you to visualize
how long it is, just think of this: the last time Planet Nine was in the same place, mammoths
were still roaming our planet. Oh, and there were barely a few million people
on the whole Earth. Of course, until scientists see Planet Nine
with their own eyes, they can't say for sure that it exists. But the evidence they have is quite solid,
and the chance that the planet doesn't exist is really small - like one in 15,000! Otherwise, why would 13 space objects outside
the orbit of Neptune behave so strangely, clustering and tilting in a weird way? Only if a massive, far-away planet made them
all swing in one direction! And since there is no other massive planetary
body in that area - hello, Planet Nine! Beware, astronomers are on the hunt! Obviously, with such an enormous distance
separating Earth and the hypothetical planet, it's bound to be very difficult to spot "Fatty." But scientists don't give up hope: they're
looking for the planet using infrared equipment. If Planet Nine does exist, it's supposed to
leak infrared radiation. But so far, all that scientists have detected
is weird gravitational effects on the outskirts of the Solar System. But then, what if Planet Nine isn't a planet
at all? The idea, which first appeared in 2019, suggests
that the object that has created all this hullabaloo, might be... a black hole! Wait, wait, wait. Does it mean it's going to swallow us and
all the Solar System? Astronomers have divided all black holes into
three groups: supermassive black holes, intermediate-mass black holes, and stellar-mass black holes. The supermassive black hole closest to Earth
is Sagitarrius A*, perched almost in the center of our home Milky Way galaxy. Such supermassive black holes are gargantuan,
they can control the way stars form and, being awake and feeding, they can be the brightest
objects in space. But even small black holes are still way bigger
(and, honestly, even more impressive) than our Sun. Around black holes, there are swirling discs
of material, and the whole picture resembles water going down a drain. Black holes generate so much radiation that
even astronomers on Earth manage to detect it with their telescopes. But apart from these impressive giants and
smaller holes, there might be one more type of black holes - primordial. The problem with them is that scientists have
never got any real proof of their existence - they just suppose that there are primordial
black holes somewhere out there. These holes are insanely old and quite tiny
(of course, by black hole standards). Astronomers believe that they appeared some
milliseconds after the Big Bang and might have witnessed the whole history of the Universe. At that time, not even stars or galaxies were
born yet. By now, the smallest primordial black holes
are likely to have evaporated away, but the bigger ones can still be scattered around
the Universe. As for how primordial black holes appeared
in the first place, in the very beginning, space wasn't the same. In some places, it was hotter, in others - cooler,
and some regions were denser. Sounds like some of the people I hang out
with. Scientists suppose that these dense areas
could collapse into primordial black holes. But the most interesting thing is that these
holes are likely to be so small exactly because they popped up right after the Big Bang! The longer it took them to appear, the larger
they were. The difference could vary from the mass thousand
times greater than that of the Sun to the weight of a Jelly Bean. But let's return to Planet Nine - or should
I call it Primordial Black Hole Nine now? Once again, astronomers haven't seen the planet
with their own eyes. The only thing that proves its existence is
how it influences the behavior of other space bodies. But let's not forget that black holes are
also notorious for their gravitational pull! So, why don't we suppose that the thing hiding
on the outskirts of the Solar System isn't a mysterious, unidentified planet, but a mini
black hole? But even if this guess is correct, you have
nothing to worry about: Earth isn't in danger. Primordial black holes are too small and weak
to cause any serious harm to our planetary system. But at the same time, they can mess with objects
careless enough to get too close. (slurp – oops!) But what made astronomers come up with the
idea of primordial black holes at all? For one thing, it was an inexplicable brightening
of stars, as if some massive but almost transparent object was passing in front of them. What's more, these stars not only started
to shine brighter for a brief moment, but they also seemed curved, as if you were looking
at them through a gigantic magnifying glass! Besides, when scientists created a computer
model of a primordial black hole 5 to 10 times as heavy as Earth and with an orbit very distant
from the Sun, they got really interesting results. The pattern of this model resembled the events
happening in the region of Kuiper belt a bit too much for it to be a coincidence! And finally, a primordial black hole would
explain why hypothetical Planet Nine can't be seen and doesn't produce infrared radiation. But one of the main reasons why astronomers
would be ecstatic should Planet Nine turn out to be a primordial black hole is the mystery
of dark matter! You might know that scientists are still in
the dark (yes, the pun was intended) about what exactly dark matter is, which makes up
to 30% of the Universe. But guess what? Primordial black holes could be the very dark
matter astronomers are searching for! Or at least, a kind of dark matter named MACHOs
(which stands for massive compact halo objects). Well, it makes me believe that with astronomers
being so motivated, we'll soon get to know the real nature of Planet Nine slash Primordial
Black Hole! Or maybe -- it’s only a half-mass black
hole… can’t wait to find out! Hey, if you learned something new today, then
give the video a like and share it with a friend! And here are some other videos I think you'll
enjoy. Just click to the left or right, and stay
on the Bright Side of life!
