New research predicts that planets can accumulate enough dark matter to suddenly form a black hole in their core.

As the intruder grows, disaster unfolds: it will swallow the world from the inside out, turning into a black hole with the mass of its unfortunate victim.

The results, published as a study in the journal Physical Review D, are terrifying.

However, the goal is not to haunt our dreams, but to show a potential new opportunity for studying dark matter, the invisible substance that makes up 85% of all mass in the universe.

This would only affect gas planets, so Earth is safe for now.

"In gas exoplanets of various sizes, temperatures, and densities, black holes can form on observable timescales, with potentially even multiple black holes forming over the lifetime of an exoplanet," said co-author Mehrdad Foroutan-Mehr, an astronomer at the University of California, Riverside.

"These results show how exoplanet studies can be used to search for superheavy dark matter particles, especially in regions thought to be rich in dark matter, such as the galactic center of our Milky Way," he added.

Astronomers still don't know what dark matter actually is. We know it exists because of its gravity, which governs the formation of the largest structures in the cosmos. Beyond that, it's a truly ghostly phenomenon.

The prevailing model suggests that dark matter consists of weakly interacting massive particles, or WIMPs, which are heavy and slow enough to clump together and form huge "halos" of dark matter that give rise to entire galaxies.

WIMPs also do not interact with ordinary matter or even light, making them effectively invisible.

It is believed that these particles can annihilate upon collision, releasing gamma rays that should be detectable, but so far, efforts to find evidence of these collisions have been unsuccessful.

In the study, the researchers take a different approach and suggest that dark matter particles are heavy but do not annihilate.

Near the center of the galaxy, where the concentration of dark matter is highest, this means that a massive gas giant like Jupiter could capture some of these dark matter particles in its core.

There, the rare interactions between dark matter and ordinary matter can cause dark matter particles to lose speed, stick together, and become dense enough to form a black hole.

They found that this could happen in less than ten months.

Surprisingly, this does not necessarily mean doom for any world that has the misfortune of finding itself in the incubator of a cosmic monster.

"Whether or not the black hole in the planet survives depends on how massive it is when it first forms," Forutan-Mehr told Physics World. If it starts out small enough, it may disappear before it has a chance to feed and grow.

"The interesting thing is that there is also a special intermediate mass at which these two effects balance each other out," Forutan-Mehr added.

"In this case, the black hole neither grows nor evaporates—it can remain stable inside the planet for a long time."

If these black hole planets exist, we should be able to find them somewhere near the center of the galaxy.

Exoplanets could be a valuable way to explore and test our understanding of dark matter. But finding these planets is easier said than done. For one thing, they would be gravitationally indistinguishable from ordinary planets.

And while they would be unusually hot, this could be explained by countless less unusual phenomena.

"Rather, our thesis is that if detailed studies reveal temperatures that cannot be explained by normal processes," Forutan-Mehr told Physics World, "then dark matter can be considered one possible—though still controversial—explanation."

Instead, other discoveries could be extremely promising—such as a small black hole.

"The discovery of a black hole with the mass of a planet would be a major breakthrough," said Forutan-Mehr.

"It would support the thesis of our paper and offer an alternative to the widely accepted theory that planet-sized black holes can only form in the early universe," he explained, referring to what are known as primordial black holes.

Ideally, we would document a large population of these miniature singularities.

This "could provide strong evidence in support of the superheavy non-annihilating dark matter model," the researcher continued.

As for whether the planets in our solar system could meet their end by spawning a black hole, that is unlikely.

We are about 26,000 light-years from the center of the Milky Way — not that there aren't other cosmic horrors to worry about, of course. | BGNES