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  • Black holes are some of the most powerful

  • and violent objects in the universe.

  • They can warp space and time

  • and rip entire stars to pieces.

  • So, what if I told you that astrophysicists

  • think there's one lurking in our very own solar system?

  • Reporter: Then a new discovery

  • rocked the astronomical world to its foundation.

  • Narrator: Now, before you freak out,

  • you should know that our planet isn't about

  • to get sucked up and reappear in another galaxy.

  • If there is a black hole,

  • it's at least 20 times farther from Earth

  • than the furthest planet, Neptune,

  • in a distant region of our solar system

  • called the extended Kuiper Belt.

  • The belt is home to billions of icy objects,

  • like comets and asteroids.

  • And in 2016, astronomers Konstantin Batygin

  • and Mike Brown noticed that some of them

  • have highly unusual orbits.

  • While most objects in our solar system

  • orbit the same plane, and in the same direction,

  • the orbit of these objects looks like this.

  • Some of them orbit on a slight tilt.

  • Others orbit backwards.

  • And still others orbit perpendicular

  • to the plane of our solar system.

  • Konstantin Batygin: Imagine the plane of the solar system

  • as being your table.

  • These orbits are stacked like books.

  • Narrator: They concluded that this could mean

  • only one thing.

  • Batygin: In order to generate this population

  • of highly inclined, perpendicular orbits,

  • you need some distant gravitational pull.

  • Narrator: By their calculation, that gravitational pull

  • is five times greater than Earth's.

  • So they reasoned that this "something"

  • was as large as a planet orbiting our sun.

  • In fact, they even went so far to give it a name,

  • Planet 9.

  • Now, of course, if they were to confirm this discovery,

  • it would be groundbreaking.

  • The first new planet in our solar system

  • since the discovery of Neptune in 1846.

  • Reporter: Very little is known about Neptune,

  • the last of the giants on this tour.

  • Narrator: But there was a problem.

  • No one was able to observe the planet directly.

  • Now, that could be because finding a planet that far away

  • is like searching for a needle in a haystack...

  • with the lights off

  • and only a vague idea of where the haystack even is.

  • Or it could be because, well,

  • that "something" is not a planet at all.

  • In a study published in the fall of 2019,

  • theoretical physicists Jakub Scholtz and James Unwin

  • proposed it could actually be a black hole.

  • Not just any black hole, but a primordial black hole.

  • Jakub Scholtz: Primordial black hole is a remnant

  • from the Big Bang that came from a very dense region

  • that almost instantly collapsed into a small black hole

  • right during the birth of the universe.

  • Narrator: And they do mean small.

  • About the size of a tennis ball.

  • That's right; this black hole

  • would fit in the palm of your hands.

  • While the idea might sound far-fetched,

  • it isn't totally out there.

  • For over 50 years, astronomers have proposed the universe

  • is littered with primordial black holes.

  • And we've even observed fluctuations of starlight

  • in our own galaxy,

  • which primordial black holes could explain.

  • Not only that, but Scholtz and Unwin also noticed

  • that if a primordial black hole orbited the sun,

  • it would have the same effect on objects in the Kuiper Belt

  • as a large planet.

  • But whether it's a black hole or a planet,

  • there's another mystery.

  • Where did it come from?

  • One idea is that the object was wandering through the galaxy

  • and got caught in the sun's gravity,

  • but for now, this is all just speculation.

  • James Unwin: If we do do our searches and it turns out

  • that there is a planet in the outer solar system,

  • this would be an absolutely incredible discovery.

  • Such a strange planet on such an odd orbit.

  • It would really change our understanding

  • of the history of the solar system.

  • Narrator: But if it is proven that this is a black hole

  • in our own outer solar system?

  • Unwin: This is completely mind-blowing.

  • And the fact that this not only would change

  • our understanding of solar system physics,

  • but it also gives us a new window into astrophysics,

  • into early-universe cosmology,

  • and into, potentially into, the fundamentals

  • of particle physics.

  • Narrator: Whether it's a planet, a black hole,

  • or something else entirely,

  • one thing is for sure:

  • When we do find the source

  • of this mysterious gravitational pull, it will be huge.

Black holes are some of the most powerful

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Why There Could Be A Black Hole In Our Solar System

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    林宜悉 發佈於 2020 年 10 月 25 日
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