It’s staggering precisely how much the rest of the universe affects Earth. From Catalyst Comets to the secrets of Mars to the remnants of alien visitors, the history of this planet has been marred by those from beyond.
Any educated person can come to understand the influence the stars have had on our tumultuous history. Almost no one realizes the reverse truth. Earth has influenced the wider universe in unimaginable ways.
~~~
Twilight and Bonnibel returned to the lab excitedly. They tripped over each other, landing in a pile at the base of the stairs. Neither spent any time considering how awkward this moment was, immediately running to the countertop where Bonnibel had left her holographic projector and notebook. She turned it back on while Twilight tore the notebook off the desk and began flipping frantically through it again.
“Absolutely fascinating…” Twilight said, finishing her initial skim of the notebook in under a minute, immediately flipping back to the front page to examine everything in further detail. “Every thousand years? Are we sure?”
“The number is likely inexact,” Bonnibel answered. “Even assuming it is keyed to the physical location of the Earth in reference to the Sun, the spatial drift would ensure that it wouldn't align precisely every thousand years. Without a proper dating system, however, there is little way to prove this.”
“I’ll have to ask Celestia…” Twilight said, flipping another page. “She would remember something like this happening. Although… she would have noticed the sky changing color a thousand years ago.”
“Unless it happened on the other side of the planet.”
“Hmm… the dead continents… there might still be a remnant.”
Bonnibel raised an eyebrow. “Do you have any idea how stupid it would be to try to explore the dead continents?”
“Yeah, I know, darkness, dismay, destruction, desolation… but there might be something here. Hmm…” She scrunched her muzzle at the book, chewing on the thought of a thousand years ago. Something was nagging at the back of her mind—there were many prophecies that mentioned a thousand years like it was something important, a major segment of history. The biggest one she knew of was the Nightmare Moon prophecy, but that had come true years ago. The timing was wrong to be correlated to the Catalyst Comet that had shown up a few weeks ago.
“You seem troubled,” Bonnibel observed.
“Something in the back of my mind I can’t quite get to…” Twilight frowned. “A thousand years ago…”
“Well, I don’t know about a thousand years ago, but I do know there was a Catalyst Comet that struck two thousand years ago, around the same time as the Mushroom War.”
“No history survived from during the Mushroom War period, how can you know that?”
“Page 96.”
“If you’re referring to the Comet’s continued spirit-nexus, I’m afraid I don’t see the connection. The ongoing flow of destiny would be impossible to measure due to the exaggerated uncertainty principle.”
“Au contraire, my purple friend,” Bonnibel said, sliding aside a panel on one of her walls to reveal a whiteboard. “If we take the aspect of thaumic consciousness as alpha and treat it as a singular point…”
“...Fascinating theory, but on what basis are you making this assumption…?”
“...It’s an assumption I’ll prove recursively at a later step, for the moment it serves as a placeholder. Set the alpha’s value to an arbitrary numerical constant and adhere it to the cosmic energies of the celestial sphere…”
“...The celestial sphere is just an approximation, though the math checks out. I’d suggest using Neighton’s constant. Beta equals…”
“...I am aware of the value, though we call it Butter’s number…”
“...Carry the two…”
“...Place the Taylor Series into locus aleph null...”
“...Evaluate the resulting transcendental function numerically for all x…”
“...And assuming the covalence of atomic bond theory is correct…”
“...We’re going to need a bigger whiteboard…”
“...I have more in the box…”
~~~
About every thousand years, a comet is ignited by the magic of the Earth itself. No matter what the state of magic is in the current era, the comet is called, and despite efforts by past inhabitants, nothing has ever stopped the transmission. The comet ignites, becoming a living paradox of ice and colored flame. It is born with one instruction.
Come.
And so it does. From beyond the orbit of Neptune, the supernatural glacier hurls itself at the only naturally habitable planet in the Solar System.
Bonnibel and Twilight spent three hours deriving the magical equations to establish this simple fact, making two errors along the way that neither noticed. This did nothing to change the truth of their deductions, though in the future each would notice one of the errors and fix it, only to realize it skewed the results. The mistakes, by pure chance, canceled each other out.
All this to say, the two of them found the art of mathematically proving the Catalyst Comets’ existence riveting in a way nobody else would. Everyone else would only care about the conclusions: namely, what a Catalyst Comet does.
First, the physical effect. It crashes into the Earth. The precise result of this fallout depends entirely on the Comet’s physical size, which has varied from barely larger than a baseball to large enough to wipe out the dinosaurs. Normally, this physical interaction is the least influential part of the Comet’s existence.
As far as the forces of destiny and divination are concerned, the Comets herald great eras of change. Often events leading up to and after the strike of a comet are tense, marked by major shifts in the course of history. The Comet of the Mushroom War arrived in the midst of an apocalypse. Two comets prior, The Comet of the One coincided with the birth of the most influential human in history. On the reverse side of time, two comets forward, The Comet of the Dissipation arrived, coinciding with change the world hadn’t quite realized yet. Beyond the fact that it turned the sky purple, of course.
There is a third effect, however. Every Comet that strikes the Earth dies.
But each Comet carries with it a rare soul that cannot die.
~~~
“...And so, the spirit of the Comet cannot move on due to an excess of energy, nor can it be dissipated without the proper channels!” Bonnibel slammed her marker into the seventh whiteboard and drew a solid black square. Despite being made almost entirely of bubblegum, her hair still somehow managed to look frazzled and mangy, though it was nothing compared to the disheveled mess that was Twilight’s.
Neither of them cared. They had just been through the best SCIENCE! session of their lives.
“So… what happens to the spirit then?” Twilight asked. “It can’t become a ghost. If the situations were proper for such a thing it would dissipate into the cosmos as a whole. It would have to find… something… else…” Twilight squealed. “A new body!”
“Yes! The ancient philosophy of reincarnation is an apt description of the process!”
“That’s how you know so much! You’re a Comet spirit, aren’t you?”
Bonnibel stared at Twilight blankly for several seconds before breaking out into laughter.
Twilight rolled her eyes. “Yeah, yeah, laugh it up. It was the most logical assumption!” Bonnibel started laughing harder. “It was!”
“No, no, I just know a Comet spirit,” Bonnibel managed through her sputtering. “It’s Finn. He’s the Spirit of the Comet of the Mushroom War.”
Silence filled the lab that was previously filled with laughter.
“Finn,” Twilight deadpanned.
“Yep.”
“Doesn’t exactly… strike me as the type.”
“Well, he is human.”
“HE’S HUMAN!?” Twilight shrieked.
Bonnibel rubbed her ears. “Y-yeah.”
“How? I thought they were extinct!”
“We’re not entirely sure how. He found his father recently, but the man never explained everything and isn’t around anymore.” She frowned. “Something about making a deal with the Comet.”
“Wait… is he why the Comet vanished instead of hitting?”
“It was a mixture of a lot of factors. There was an ancient deity by the name of Orgalorg trying to siphon power from the Comet for evil purposes, there was a space moth, Finn and Jake were up there in a rocket ship…”
Twilight stared at her in disbelief.
“Oh come on, you can’t tell me that you, Princess of Friendship, haven’t dealt with more ridiculous things.”
“I… well… there was Tirek… and the Everfree… and Disco—DISCORD!”
Bonnibel cocked her head. “What does he have to do with anything?”
“Discord! The Spirit of Chaos and Disharmony, he… his reign of chaos was happening around one thousand years ago today, wasn’t it? The previous Comet would have struck during then! Of course nobody noticed it, he was turning the entire world into his playground of chaos at that time! Ha!” Twilight smiled smugly. “I knew there was something a thousand years ago! Ha!”
“He was released recently too, wasn’t he?” Bonnibel scratched her chin. “Maybe the Comet has already been changing things from afar…”
“Still is released. My friends and I befriended him. He has tea with Fluttershy every week.”
Now it was Bonnibel’s turn to stare at Twilight in disbelief.
“I can call him if you want. He’s got a direct connection to me via the Elements. We set it up back when we wanted to keep an eye on him.”
“No!” Bonnibel blurted. “That’s fine, really! No need to get a visit from the Spirit of Chaos today! Nope!” She laughed nervously.
“He’s really not that bad.”
“You forget he would ruin our science with his presence.”
“True…”
“Hey!” Bonnibel jumped over to a box. “Now that we’ve established some things about the Comet…”
“I still have a lot more questions.”
Bonnibel pulled a large tripod telescope out of the box and raised an eyebrow.
Twilight took in a sharp breath of air. “My questions can wait.”
“Thought so. C’mon, let’s go to the roof. Jupiter should be visible on the western horizon.”