A provocative theory gaining traction in astrophysics suggests that ancient, atom-sized black holes may be quietly drifting through our planet—and even through our bodies—without leaving a trace. These objects, known as primordial black holes (PBHs), are theorized remnants from the Big Bang, and some scientists believe they could account for the unseen mass that makes up most of the universe.
The startling idea, while it might sound like science fiction, is rooted in a growing body of theoretical and experimental research. If proven, it could rewrite what we know about the universe’s formation, its hidden structure, and the elusive nature of dark matter, the invisible substance thought to make up roughly 85% of all mass in the cosmos.
At the center of this renewed interest is a new paper by physicist Dr. Dejan Stojkovic and his team at the University at Buffalo, arguing that PBHs may pass through ordinary matter at relativistic speeds—effectively undetectable and harmless. Unlike the supermassive black holes anchoring galaxies, these theoretical micro black holes would be no larger than an atom, with the mass of a small asteroid.
Are Black Holes Hiding in Plain Sight?
For decades, dark matter has remained one of modern physics’ most vexing puzzles. Astronomers observe its gravitational effects on galaxies, but repeated attempts to detect its particles—WIMPs, axions, and others—have come up empty. As observational dead ends multiply, theorists have turned back to an old but largely shelved idea: what if dark matter isn’t a new particle at all, but made of black holes formed during the universe’s earliest seconds?
In this model, extreme density fluctuations shortly after the Big Bang could have collapsed regions of matter into PBHs, distributed throughout space. They wouldn’t emit light, wouldn’t interact with electromagnetic fields, and would be nearly impossible to detect—except via their gravitational effects.
This isn’t just idle speculation. As the University at Buffalo research team points out, if a PBH were to pass through a solid object, it would do so almost invisibly. “A black hole of this size would pass through matter almost unnoticed. It would not slow down and would cause no damage,” Stojkovic explained in a recent interview.
Such claims are consistent with Einstein’s theory of general relativity, which allows for the formation of black holes from any region where mass density exceeds a certain threshold. Crucially, the smaller the black hole, the more it would evade detection—making them plausible dark matter candidates, according to recent work published in Physics Letters B and echoed in the Monthly Notices of the Royal Astronomical Society.
What if One Hits Earth?
The idea that a black hole could pass through Earth—or even get trapped inside it—raises obvious concerns. But researchers stress that the risk of catastrophic damage is extremely low. A primordial black hole passing through Earth would likely release negligible energy, too small to heat or alter surrounding matter in a meaningful way.
The more speculative question is what happens if such an object gets gravitationally bound inside a planet. In theory, over billions of years, a trapped PBH could slowly consume material at a planetary core. This process, though, would be so slow and inefficient that its effects might remain undetectable for the lifespan of the solar system.
According to astrophysicist Dr. Katherine Freese, a leading expert on dark matter at the University of Texas, “Primordial black holes remain an intriguing possibility. They evade many of the experimental constraints applied to particle dark matter, but the challenge is in proving their existence.”
The search has already begun to adapt. Researchers are now exploring gravitational microlensing surveys, data from LIGO’s gravitational wave detections, and even anomalous heat flows from planetary interiors as possible indirect signs of PBHs. In 2019, a study in Nature Astronomy proposed looking for “missing asteroid” patterns in the solar system that might point to past PBH encounters.
From Pet Cats to Cosmic Forces
What’s drawn public attention to this topic recently is the idea—floated half-seriously in a recent Daily Galaxy article—that a PBH could pass through your cat, your home, or your body without a trace. It’s not incorrect, just exaggerated. The reality is quieter and more unnerving: if PBHs are real, they’re everywhere, and we’d never know.
More seriously, PBHs offer one of the only non-particle-based solutions to the dark matter problem. That alone has revived interest from scientists frustrated by the repeated failure to detect new particles in collider experiments and deep underground labs.
Moreover, they might explain other anomalies. For instance, the early formation of supermassive black holes—visible only a few hundred million years after the Big Bang—has baffled astronomers. PBHs could act as seeds, rapidly pulling in matter to grow into the monsters we observe at galactic centers.