Is Planet X a Black Hole?

Scientists have been proposing a new “Planet X” in our solar system. Now two scientists suggest that it’s a black hole. Find out why.

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I own a telescope.  It’s small and unadorned, but well made.  Using it, I’ve been able to see five of the planets in our solar system.  The easiest one to spot is Venus because it’s the brightest object in the night sky, not counting the moon.  Watching Venus progress from a crescent shape to its full disc, just like the lunar phases, is mind-blowing.

Another easy one is Jupiter, which is almost as bright due to its size.  It’s always startling to follow the four largest moons of Jupiter in their graceful orbits.  I think the most beautiful planet for stargazers is Saturn, not only because we can see its rings, but because of its golden colour.  The trickiest one is Mercury.  It’s so close to the sun that we can only catch it very close to the horizon.  The sun’s light makes it hard to locate.

Discovering the outer planets took both a telescope and some specific analytical skills.

Readers may wonder why I’ve only managed to look at five of the planets. Honestly, that’s not a bad record. I’m doing as well as Galileo and everybody else up until the 18th century. These are all the planets we can spot with the naked eye to aim our telescopes. Discovering the outer planets took both a telescope and some specific analytical skills.

Uranus came first.  William Herschel noticed it in 1781 without looking for it.  He was using his telescope to catalogue all the objects we can’t quite see with the naked eye.  Herschel noticed a faint, blurry object moving in front of the stars.  He thought it might be a comet, but when he and the Astronomer Royal did the math, they found that it was a new planet.

Speaking of doing the math, that’s how three scientists independently found Neptune in 1846.  In 1845, analyzing the orbit of Uranus, Urbain Levarier and John Couch Adams each used calculations to show that there was a planet beyond Uranus and to point to where it should be in the sky.  Johann Gottfried Galle spotted it in 1846.

In the same way, by analyzing the orbits of Uranus and Neptune, Percival Lowell predicted the existence of Pluto in 1905.  He never lived to see it, but Clyde Tombaugh found it in 1930.  Pluto was demoted to a dwarf planet in 2006.  I felt sad about this until I found out that it’s the biggest dwarf planet in our solar system.  I guess it’s now a big fish in a small pond.

For the last five years or so, they’ve been suggesting that there is another planet out there.

Scientists are still doing the math.  For the last five years or so, they’ve been suggesting that there is another planet out there.  For now, they call it Planet 9, or P9 for short.  Some call it Planet X.  Last week, Jakub Scholtz from Durham University and James Unwin from the University of Illinois suggested something more radical.  They believe that this potential planet is actually a small black hole.

They get this idea from two findings.  The orbits of the small objects outside Neptune don’t match our calculations, even taking Pluto into account.  Also, the Optical Gravitational Lensing
Experiment (OGLE) is finding that something is bending the light from distant stars.  This type of bending effect happens when starlight goes past massive objects, like the proposed Planet X.

They go on to propose that one of these black holes is orbiting our sun

Most astronomers believe that the “gravitational lensing” is caused by a series of free-floating planets.  Scholtz and Unwin suggest that they’re a series of primordial black holes.  They go on to propose that one of these black holes is orbiting our sun.

If they’re right about this, the black hole would be surrounded by a ring of dark matter.  If dark anti-matter collided with that dark matter, it would produce bursts of gamma rays.  That’s the next step for these scientists.  They plan to go through the data from the Fermi Gamma-Ray Space Telescope.  They hope to see clustered, intermittent gamma-ray flashes moving slowly through space.

We need to get a grasp on the nature of what we call dark matter for lack of a better term.


Nobody, including the researchers, knows if they will ever prove that Planet X is a black hole. That’s not necessarily the point. Their detailed analysis will unlock new information about dark matter and gamma-rays. They’re sure to learn things from it, even it doesn’t prove their point.

We need to know more about black holes and especially about dark matter.  Right now, dark matter makes up about 27% of our universe, while everything we can actually observe represents only 5%.  To understand our role in the cosmos, we need to get a grasp on the nature of what we call dark matter for lack of a better term.

We always have more to learn if we dare to know.

Learn more:

Science (AAAS)
What if Planet 9 is a Primordial Black Hole?
https://daretoknow.ca/2019/11/04/why-mars-why-not-venus%e2%80%a8/

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