You may have heard of Planet X or Nibiru. Ghostly planets said to haunt our solar system. Today we’re going to look at a forgotten hypothetical planet first encountered on a cool autumn night in 1934.
But this planet, like the astronomer who discovered it, vanished just as quickly as it first appeared, leaving only questions in its wake.
This mysterious celestial body was simply known as the Black Planet.
I. Dreams of Discovery
The astronomical community was ablaze with excitement in the early 1930s. With the discovery of Pluto in February of 1930, the international community was on fire. Every telescope was pointed skyward. There was a race on to see which astronomer could make the next big discovery.
An administrator at The British Royal Observatory in Greenwich, William Haywood Arundell went on about his work, pretending to not be bothered by the excitement all around him. He was largely responsible for doublechecking mathematical calculations and collecting together observations made by the astronomers. His was a desk job.

However, from his home observatory, this amateur astronomer dreamed of making a discovery of his own to cement his name in history beside that of Clyde Tombaugh, the discoverer of Pluto.
Arundell was an odd figure. Tall and somewhat ungainly, he went about in tweed jacket and bowtie, going about his business quietly. He was a reclusive figure to his neighbors and work colleagues. But to those whom talked with him on matters of astronomy found a quiet, abiding passion for the stars under Arundell’s placid exterior.
From his country home in Surrey, Arundell spent many wistful nights hoping to see something extraordinary, to be the first to see some great wonder through the lens of his homemade telescope.
It was here, at his home observatory, that Arundell first encountered the Black Planet. It was a crisp autumn night in late 1934. It was late at night. A bout of nervous energy had kept Arundell up. He had quite forgotten what time it was.
Then all of a sudden he was asleep. He fell asleep so quickly that he didn’t realize he was dreaming when he opened his eyes.
He could no longer look straight at his charts. The data on them seemed to slide around and elude his gaze (anyone who has tried to read anything while in a dream will know what this is like).
Then he looked up.
Outside his window hung a black disk in the night sky. He at once realized it was a planet, but impossibly close. It was many times larger than the moon and hung like a circular curtain, blotting out stars. He knew it was a planet, though the small, logical side of him told him this was impossible.
He could just make out details on the part of the planet where an arc of moonlight fell: the lighter points of mountaintops surrounded by twisting black valleys of deep shadow. It seemed a very enchanting world, under its shroud of perpetual night.
He woke up with a start and immediately wrote down what he saw in his diary:
“Though at that moment I knew I was of course dreaming, I couldn’t but help and marvel. There was something awfully real about the world, as strange at that sounds now. It was like an ornament or a bauble hanging their, taunting me, enticing me. The moment I woke up, I swore then and there to find proof of just such a planet actually existing.”
True to his word, Arundell set out to discover the planet which he had seen in his dream.
II. A Shadow Beyond Neptune
A silent change came over William Haywood Arundell. Many of his coworkers didn’t notice until much later. But this amateur astronomer was now on a quest to find the dark planet of his dreams.
What had been merely a hobby became an obsession. Arundell spent almost every night looking up at the night sky through his telescope at his Surrey home. He yearned to see the planet of his dreams. His journals became nothing else but his mission. It’s all he thought about, all he dreamed about.
Arundell labored in silence for half a year before he found the sign he was looking for. He records feeling increasingly depressed as the days became weeks, and the weeks months.
On night, Arundell recollected a crucial detail from his dream which began this search. The stars, which stood out most in his mind, were those of the constellation Leo. At that time, Neptune was in Leo. So Arundell took to scrutinizing Neptune each night. He waited now with baited breath, hoping to see something.
Then in early 1935, he saw it. Arundell made a hasty, excited entry in his journal complete with a hurried sketch.
He had seen a shadow around Neptune.
It was, he knew in his gut, the Black Planet of his dream. He had seen an unidentified body occult a star of Leo beyond Neptune. Occultation is when a celestial body passes between Earth and a distant start or planet.

In a fever of excitement, Arundell kept vigil each night, looking for any further occultations to let him know how distant this object was and what its orbit was.
The quick sketch of a black circle filled in with pencil-strokes, becomes important later. For even in this first encounter, Arundell drew a strange little squiggle in the center of the planet. This will be important later.
The astronomers at Greenwich had noticed this shadow too and now began looking beyond Pluto with growing interest. However, they presumed it was merely a commet or an asteroid, as the level dimness of occultation led them to believe it was a small body within the outer extremities of our solar system.
Only Arundell knew its true nature.
Through many nights of observation, he plotted out its speed and trajectory. The occultations, when they appeared were growing more complete. The object was drawing closer.
He envisioned a fast moving planet, darting swiftly among the inhabitants of the outer Solar System. Arundell realized that the orbit of the Black Planet was not regular. He had not discovered a new planet beyond Pluto because the Black Planet was on a spiral orbit through the other planets.
Arundell wrote a paper based on his findings titled “Cosmic Wanderers: Terrestrial Bodies Without Stars”. Here he put forward the theory of what he called “free-roaming” or “wandering” planets.
While ridiculed at the time by his peers, this theory would later be proved in the early 2010s by the discovery of rogue planets. Rogue planets are celestial bodies which have no stars or regular orbits, but merely drift through the galaxy.
Arundell was sure now that his dark planet was just one of these galactic strays: a sunless world that was hurtling through the galaxy, wandering past star systems and through the interstellar voids. And it just so happened that it had entered ours on its journey of a hundred thousand lightyears.
It was serendipity that it was now, exactly when Arundell was looking to the night sky, that this shadowy traveler appeared.
Though his theory was mocked and Arundell literally laughed out of a meeting in Greenwich, Arundell was convinced he was right. Though other astronomers had seen the occultations, they of course found the idea of a planet of considerable size moving through our Solar System ridiculous. None of the outer planet’s showed alterations to their orbits, which a new planet would have done on a massive scale.
And the speeds at which this planet would have to be moving would have surely stripped it of its atmosphere. A planet moving as fast as a comet was beyond preposterous.
Yet Arundell knew his calculations were correct. He had double and triple checked his math. And he knew with certainty where the Black Planet’s path was taking it.
Straight toward Earth.
III. Dark Dreams of a Dark Planet
William Arundell came once more before the venerable astronomers of the Royal Observatory. He announced his finding to them. The Black Planet was spiraling through the Solar System, gracefully avoiding the outer planets and now the asteroids of the belt.
Soon, the Black Planet would pass very close to Earth. Or perhaps even colide with it.
However, at this point, no other astronomer could see the planet. It had become a shadow, letting itself be seen only by Arundell it seemed.
At this point, Arundel had become a joke: an amateur astronomer so thirsty for glory and fame he had stepped into the delusional, coming up with a farce simply to get attention.
His announcements certainly created a stir, but they were so quickly and thoroughly refuted by astronomical authorities worldwide that he soon lost all credibility.
William Haywood Arundell withdrew into his country home and was seen less and less.
To his dwindling circle of friends and associates, including fellow astronomer John Middleton, a disheveled, pale-faced Arundell shared his latest and strangest discoveries.
Sitting in his small parlor with only a few lamps casting their yellow glare on Arundell’s haggard face, he told his friends about detailed sketches he had made of his planet’s surface.
Now many thought these were made from pure fantasy, but those that humored Arundell and asked how he had seen this level of detail on the planet’s surface were met with a bewildering reply.
The sketches, made in Arundell’s meticulous hand, showed unexplored mountain ranges, winding valleys, and seas of black water never before crossed by any ship. Arundell described a world of savage natural beauty: a land of eternal, star-lit night where huge black forests covered a wild land, where black mountains thrust their proud heads up towards the ever-changing panorama of the night sky.
And, standing amidst these features stood a tall, tree-like shape much like an image of Yggdrasil from Norse mythology. Even in his first sketch, this tree was visible as the ambiguous squiggle mentioned earlier in the post.
In a small, neat hand was the word “Ko’osh” beneath the tree. When asked about the tree, Arundell was vague, only hinting that it was important to “them”.
Arundell claimed that his rogue planet was inhabited by a race of beings who were once physical, had once lived on the world as terrestrial beings. But then, after some strange and unknowable event, they became beings of shadow and thought.
When asked how he knew all this, Arundell, a mad gleam in his dark eyes, replied he had been contacted by them.
They had reached out with their minds. Out of all the teaming masses of humanity, they had chosen him. Arundell felt that it was some will of fate or nature that these strange events had coincided exactly in his lifetime.
Middleton recounts in his diary Arundell’s description:
“I awoke from a dream in the middle of the night. This was some weeks ago. The night was very still and very dark. Around my bed stood six tall figures. They stood in a ring. I was not afraid—not to say that I didn’t feel a thrill, certainly part of it fear. But I wasn’t afraid of them, if you know what I mean. They were ghostly white. They wore long robes of some type of pearly gossamer, from their heads to their feet. Their figures underneath where shimmering like white mist, like washed bones. They were beautiful/ And they were terrifying, because they were so beautiful.”
Arundell then repeated his warning which he had given to Greenwich: that the Black Planet was going to pass very close to Earth. And Arundell himself seemed unsure if that was a good thing or not.
John Middleton and the others left feeling deeply disturbed. Middleton slowly distanced himself afterwards from Arundell.
Some of the last calculations recorded by Arundell had to do with calculating the speed of the object so he could know on exactly what day it would come closest tot Earth. He shared his findings in his journal.
The day was September 13, 1936.
On the evening of that day, John Middleton decided to visit Arundell. It had been many weeks since they had seen each other. Middleton came late in the evening to Arundell’s Surrey home. After a while of knocking, Middleton let himself in.
No one was home.
IV. Without A Trace
Though John Middleton looked and looked, he found no trace of Arundell. He left, thinking the man was out, which was unusual for him. A few days later, the police were called when Arundell had yet to be seen by anyone.
No trace of William Haywood Arundell was ever found.
Most came to believe Arundell, being under incredible mental distress, had run off, perhaps in the hopes of deluding people into thinking he had been taken away by his shadowy world.
Though John Middleton had been estranged from Arundell for some time, they had at one time been friends. Arundell’s disappearance bothered Middleton greatly. It was mostly he who searched through all of Arundell’s journals and notes, unearthing his detailed sketches of his fantastical world, all of Arundell’s precise calculations, his photographs and charts.
What John Middleton remmebered until the day he died was one of the last things William Haywood Arundell had said to him. After explaining that the Black Planet was a galactic wanderer, he told Middleton that the Black Planet would doubtless return to our Solar Sytem.
And this time, everyone would see it.
When asked, Arundell said the beings of the dark planet had told him this.
The sightings, the dreams were all chalked up to the delusions of an obsessed mind. The hunt for a new planet had consumed Arundell to the point of mental instability. His disappearance was never explained. And no body was found. By the early 1940s, with World War II raging, Arundell was quietly declared legally dead. And that was the last anyone thought of the reclusive amateur astronomer from Surrey.
V. The Black Planet

The Black Planet, if it passed by Earth at all, left no sign of its passage. Surely a planet as one described by Arundell would have caused cataclysmic destruction on Earth. But the only corroborating sign of its coming are scattered astronomical observations, some of which were discredited in the following decades.
Some astronomers claimed to have seen a shadow or semi-eclipse of the Moon. Others of seeing a shadow pass by the sun and dimming of stars on the far side of the Solar System.
The Chermont Mental Asylum in Lincolnshire, England records a high than usual number of nocturnally disturbed patients on the night of Arundell’s disappearance, September 13th.
Additionally, there are at least two separate accounts, one from the diary of an American astronomer and the other from a British parson in Yorkshire. Both record having disturbed sleep. The parson spent most of the night awake. Both record seeing—or dreaming of—a black disk in the sky, eclipsing the stars.
This evidence is of course anecdotal and still does not prove a rogue planet passed through our Solar System.
In the end it seems Arundell was taken along as a voyager. H was scooped up by the strange beings of thought and darkness who made the sunless world their home. They took Arundell along with them on their black ark as it hurtled past our sun and off into the night of interstellar voids.
Perhaps, William Haywood Arundell finally found there what he was looking for.
But we may never know for sure.
Unless of course Arundell was right and the Black Planet will return someday to Earth.
Until then, we’ll keep digging for the truth.