Dark matter may be made of pieces of giant, exotic objects — and astronomers think they know how to look for them
Searches for dark matter particles have come up empty so far, driving theorists to get more creative with their ideas.
There are many particle candidates for what makes up dark matter. (Image credit: Naeblys/Getty Images)
Exotic, dark astrophysical objects may be hiding in interstellar space, and a new proposal outlines how to find them: stare really, really hard.
We don't know what dark matter is, even though we strongly suspect it exists. We see circumstantial evidence for it everywhere, from the rotation rates of galaxies to the growth of the largest structures in the cosmos. For decades, cosmologists have thought dark matter is some sort of exotic particle that was previously unknown to the Standard Model of particle physics. This strange particle would not interact with light, or really much of anything else, except through its gravitational influence.
It could be that dark matter isn't made of zillions of tiny particles flying through the universe. Instead, it could be composed of bunched-up collections of much larger objects. In particular, the researchers behind a new study, published in November 2025 in the open access server arXiv, investigated two kinds of exotic objects.
The first is known as a boson star. In this model, dark matter is made of an ultra-ultra-ultra light particle — potentially millions of times lighter than neutrinos, the lightest known particles. They would be so light that their quantum nature would make them appear more like waves at galactic scales than like individual particles. But these waves would sometimes bunch up and collect on themselves, pulling together with their own gravity, without collapsing.
Another possibility is called Q-balls. In this model, dark matter isn't a particle at all but rather a quantum field that soaks all of space and time. Due to a special property of this field, it could occasionally pinch off, creating gigantic, stable, lump-like balls that wander the cosmos like a floating piece of flour in gravy that hasn't been mixed well.
Both boson stars and Q-balls, which live under the more general heading of exotic astrophysical dark objects (EADOs), are difficult to detect. They're large — roughly star-size — but they do not emit light of their own, making them nearly invisible in our scans of the cosmos.
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