New Research Reveals that 'Planet X' Could be a Primordial Black Hole
A compelling new theory is floating around the scientific community that phenomena attributed to a mysterious "Planet X" may actually be a primordial black hole lurking on the edge of our solar system, according to Business Insider. The theory was published this week on arXiv.org operated by Cornell University and is pending peer review.
Planet X (also called Planet 9) made headlines in 2015 when Caltech astronomers ran mathematical simulations on objects in the Kuiper Belt in an effort to justify their irregular orbits (the Kuiper Belt is a larger version of the asteroid belt that is home to asteroids, comets, and dwarf planets). They concluded that, based on simulations, a massive planet has been orbiting the edge of our solar system and that its gravitational force is acting on these objects.
If Planet X exists, it is theorized to be about the size of Neptune and ten times Earth's mass, with an orbit that takes 10,000-20,000 Earth years to complete according to NASA. For context, ten thousand years ago, the wooly mammoth still existed. Twenty thousand years ago was the late Paleolithic era.
But the Planet X theory doesn't account for everything: light traveling through our solar system is actually bending because of an object that we can't see, and the object doing that also has a mass of approximately ten Earths. Researchers propose that it's myopic to assume a planet is responsible for this distortion of light and orbit – and suggest that a primordial black hole the size of a bowling ball may be responsible.
Astronomers classify black holes in three categories: supermassive, intermediate-mass, and stellar-mass. All of these are theorized to have formed several hundred thousand years after the Big Bang; this is because black holes are currently known to develop in the aftermath of supernova explosions and stars take at least that long to form and die.
Primordial black holes are an unconfirmed but compelling fourth type of black hole posited to have formed one second after the Big Bang, before any stars or galaxies existed to feed them. The theory goes that nature is inherently messy and, as a result, when the universe exploded outwards some areas were "denser and hotter than others," as astronomy.com explains it, and these areas then collapsed in on themselves to form black holes within milliseconds. It makes sense: there's no reason to think that the Big Bang was this perfect and uniform phenomenon – explosions have no reputation for neatness.
With that in mind, what comes next? Well, direct observations would be helpful: until we get visual confirmation, this entire article is just an exciting theory. Researchers will now begin to scan the skies for radiation signals consistent with a black hole.
You can read the paper in its entirety here.