🌀 A hundred invisible galaxies around the Milky Way?

The Milky Way could be surrounded by dozens of yet-undetected satellite galaxies. Scientists are using advanced simulations to predict the existence of these invisible structures.

Satellite galaxies are small galaxies orbiting larger ones like the Milky Way. Using high-resolution dark matter simulations, researchers estimate there could be over 100 additional ones. These potential discoveries could support the standard model of cosmology.


Dark matter, though invisible, plays a crucial role in galaxy formation. It makes up about 85% of the Universe's matter. Scientists detect its presence indirectly through its gravitational effects on stars and light.

Dwarf galaxies, captured by the Milky Way's gravity, gradually lose their dark matter and stars. This process makes them extremely faint and difficult to observe. New technologies like the Vera Rubin Observatory might soon reveal them.

The discovery of these missing galaxies would be a victory for the ΛCDM theory. It would also demonstrate the power of predictions based on the laws of physics and mathematics. Astronomers eagerly await data from future telescopes.

What is dark matter?

Dark matter is a still-mysterious substance that doesn't reflect, absorb or emit light, making it invisible to traditional telescopes. It's detected only through its gravitational effects on visible objects in the Universe.

Scientists estimate dark matter constitutes about 85% of the Universe's total matter. It plays a key role in galaxy formation and structure, acting as a 'scaffold' around which visible matter clusters.

Despite its abundance, the exact nature of dark matter remains one of modern cosmology's greatest mysteries. Research continues to understand its composition and properties.

The discovery of additional satellite galaxies could provide valuable clues about dark matter's distribution and behavior around the Milky Way.

How do satellite galaxies form?

Satellite galaxies form within dark matter halos - vast spheres surrounding larger galaxies like the Milky Way. These halos act as 'cradles' for dwarf galaxy formation.

Over time, the main galaxy's gravity pulls these dwarf galaxies, which eventually orbit around it. This process can take billions of years, during which satellite galaxies gradually lose their dark matter and stars.

This gravitational interaction explains why many satellite galaxies are so faint and hard to detect. Simulations suggest the Milky Way might host far more than currently observed.

Understanding this mechanism is essential to validate current theories about galaxy formation and evolution in the Universe.