Milky Way could host 100 undiscovered dwarf galaxies, new supercomputer simulations reveal
By isabelle // 2025-07-17
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  • Researchers using advanced supercomputers predict over 100 faint dwarf galaxies may exist near the Milky Way, undetected due to extreme dimness from gravitational stripping.
  • The discovery could confirm or challenge the Lambda Cold Dark Matter (LCDM) model, the leading theory of cosmic structure formation.
  • High-resolution simulations by Durham University suggest these "orphan" galaxies exist but evade telescopes because they’ve lost most of their stars and dark matter.
  • The upcoming Vera Rubin Observatory may soon detect these galaxies, potentially validating LCDM — or exposing flaws in current astrophysical theories.
  • If found, these galaxies would reinforce dark matter’s role in the universe; if missing, they could force a major rethink of cosmology.
Groundbreaking research using the world’s most advanced supercomputers has revealed that more than 100 faint, undiscovered dwarf galaxies may be lurking just beyond our detection, stripped of their material by the Milky Way’s relentless gravitational pull. Presented at the Royal Astronomical Society’s National Astronomy Meeting in Durham, England, this discovery could either validate the standard model of cosmology — known as Lambda Cold Dark Matter (LCDM) — or expose yet another gap in mainstream astrophysics. Led by Isabel Santos-Santos, a researcher at Durham University’s Institute for Computational Cosmology, the team combined ultra-high-resolution dark matter simulations with mathematical modeling to predict these "orphan" galaxies, which have evaded telescopes due to their extreme faintness.

Dark matter’s invisible hand

The LCDM model, the dominant framework for understanding the universe, suggests that galaxies form within vast clumps of dark matter — an invisible substance comprising 85% of all matter in the cosmos. While dark matter itself remains undetected, its gravitational effects are undeniable, warping space-time and accelerating stars to inexplicable speeds. According to Santos-Santos, "We know the Milky Way has some 60 confirmed companion satellite galaxies, but we think there should be dozens more of these faint galaxies orbiting around the Milky Way at close distances." The problem? Existing simulations lack the precision to model these faint galaxies accurately. Many simulated halos — the dark matter structures hosting dwarf galaxies — are artificially disrupted, causing their satellite galaxies to vanish from predictions. But the Durham team’s new approach, using the Aquarius simulation (the highest-resolution dark matter model of the Milky Way ever created) and the GALFORM galaxy-formation code, suggests these galaxies aren’t missing; they’re just too dim to see.

The Rubin Observatory’s coming revolution

If these predictions hold, the Vera Rubin Observatory, equipped with the largest digital camera ever built, could soon spot these ghostly galaxies. Carlos Frenk, a co-researcher and professor at Durham, emphasized the implications: "If the population of very faint satellites that we are predicting is discovered with new data, it would be a remarkable success of the LCDM theory of galaxy formation." But skeptics warn that the LCDM model is already under fire. Recent observations of dwarf galaxies have raised questions about their distribution and behavior, with some scientists arguing that the model fails to explain certain anomalies. The Durham team’s findings could either silence these critics or deepen the mystery.

A cosmic cover-up?

Why haven’t these galaxies been detected yet? The answer lies in their traumatic history. Repeated orbits around the Milky Way’s massive halo have stripped these dwarfs of their dark matter and stars, rendering them nearly invisible. The implications are profound. If confirmed, these galaxies would not only validate LCDM but also reinforce the role of dark matter in shaping the cosmos. Yet, if they remain elusive, it could signal a fundamental flaw in our understanding of the universe. As the Rubin Observatory prepares to scan the skies, humanity stands on the brink of a cosmic revelation. Will we uncover the Milky Way’s hidden satellites, or will the universe deliver yet another humbling lesson? Sources for this article include: LiveScience.com ABCNews.go.com SciTechDaily.com
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