Remember when the solar system was simple? When did you learn to say My very easy method just accelerated the naming of planets? Astronomers just had to screw it up, did not they?
Now our Solar System is filled with dwarven planets and comets disguised as asteroids and ridiculous moon loons and we can not cope. Fortunately, the case of returning a ninth planet to the list seems solid, and we may not have to wait long to see it.
We can blame the Caltech astronomer, Mike Brown, for much of this mess. If you were once a fan of Pluto, he is the man to whom you send your bottled tears for his role in lowering planetary formation.
But some of Brown's recent work may end up offsetting the loss of Pluto. Since 2016, he has been collecting evidence for a replacement for Planet Nine orbiting somewhere in the suburbs.
So why are we waiting so long? It is there or it is not. Unfortunately, hunting for the planet is not as simple as that. Astronomers could once satisfy their curiosity by tracing pinpricks of light as they glided through the heavens, like moths circling a campfire.
But what about the insects in the dark, silently crawling away from the flames? Locating them requires patience, a lot of detective work and a lot of statistics.
Suspicions about the presence of the hidden planet were raised for the first time when Brown and his colleagues noticed that clusters of objects in the cold regions of the Kuiper belt were not exactly where they should be.
There are a few reasons why this might be the case. Maybe the expectations were wrong. Maybe your data on Kuiper belt objects (KBOs) have some errors. Or maybe … just maybe … there was an invisible mass shaking their orbits.
Recent years have involved the elimination of alternative explanations, one by one, in the hope that Planet Nine will be the last hypothesis standing.
More recently, Brown has worked with fellow Caltech astronomer Konstantin Batygin to create a new method for determining bias potential in individual KBO measurements.
We can breathe a sigh of relief. Based on this new analysis, there is a 0.2% chance that clusters of tiny ice crews will cluster in this way alone, making it more likely that something will put them out of alignment.
"While this analysis does not say anything directly about whether Planet Nine is there, it indicates that the hypothesis is based on a solid foundation," says Brown.
Working back suggests that "something" could definitely qualify as a planet. And then some.
Previously, it was believed to have a mass of about 10 times and a volume four times that of Earth, with an orbit that took 75 times as far as Pluto.
Scrape it all up. Based on the most recent estimates, Planet Nine is not that far away and is a little heavier than we thought. (Still a beefcake, though.)
"In five masses of Earth, Planet Nine will probably remember a very typical extra-solar super-Earth," says Batygin.
Thousands of computer models have made the virtual equivalent of repeating the evolution of the edge of the Solar System, limiting its likely size and orbit.
Not only are we imagining it to be a fat Earth, but now it may be following an elliptical orbit that adventures it from 400 to 800 astronomical units (AU) from the Sun.
Pluto's orbit ranges from 30 to 50 AU, so while we're still talking about a long trip to the solar desert, it's not exactly the mind-boggling scale we imagined. That said, the farthest object so far confirmed in the Solar System is FarFarOut, at 140 AU.
Thus, the evidence for a new Planet Nine may be significant, but it is still largely circumstantial, until we can look far enough to see it.
"My favorite feature of the Planet Nine hypothesis is that it is testable observationally," says Batygin.
"While finding Planet Nine in an astronomical way is a big challenge, I'm very optimistic that we'll be able to imagine it in the next decade."
Well, it's never too early to start looking for a name. How about something that starts with the letter 'P'?
This research was published in Physics Reports and The Astronomical Journal.