Mysteries of dark matter unveiled by the discovery of two new galaxies

Milky Way astronomers have uncovered two new satellite galaxies, potentially offering insights into elusive dark matter.

, and Administrator

2025 August 29 . 5:58 PM

2 min read

Uncovering the enigmas of dark matter through the discovery of two exotic galaxies

Mysteries of dark matter unveiled by the discovery of two new galaxies

In a groundbreaking discovery, astronomers have identified two new satellite galaxies, Sextans II and Virgo III, around the Milky Way. This finding could potentially double the number of known satellite galaxies, challenging initial predictions and offering valuable insights into the cosmic mystery of dark matter.

Recent large-scale surveys have identified approximately 355 satellite galaxy candidates, more than doubling previous numbers, with around 134 considered high-likelihood satellites. Among these, about 264 are newly discovered dwarf galaxies identified in the latest survey efforts.

However, these findings are just the tip of the iceberg. Additional estimates from simulations and indirect observations suggest there could be up to 100 or more previously undetected faint satellite galaxies due to their small size and low brightness. Some estimates focus on around 80 to 100 such faint satellites predicted to exist around the Milky Way.

The discovery of these elusive galaxies has significant implications for our understanding of galaxy formation, dark matter distribution, and the hierarchical nature of cosmic structure. These findings contribute to our understanding of satellites of satellites around the Milky Way and smaller dwarf galaxies.

Dark matter, a cosmological mystery that does not interact with light or ordinary matter but interacts with gravity, is believed to be composed of unknown particles or tiny primordial black holes. These dark matter halos are thought to extend far beyond galactic disks and halos of visible matter.

The team of researchers, who published their findings in the Publications of the Astronomical Society of Japan on June 8, plans to use more powerful telescopes, such as the Vera C. Rubin Observatory in Chile, to get a more complete view of the night sky and confirm or correct current estimates of the number of dwarf galaxies surrounding the Milky Way.

The uneven distribution of satellite galaxies around the Sculptor Galaxy, another nearby galaxy, suggests a "favored direction." This finding could provide further clues about the role of dark matter in shaping the cosmic structure around the Milky Way.

In the early universe, dark matter halos formed gravitational wells in which gas and dust gathered to form stars and galaxies. The standard model of cosmology, the lambda cold dark matter model (ΛCDM), predicts that these dark matter halos played a crucial role in the evolution of galaxies.

These discoveries not only expand our knowledge of the Milky Way's satellite galaxies but also deepen our understanding of the cosmic web, the vast network of galaxies and dark matter that makes up the universe. The Vera C. Rubin Observatory, set to begin operations next year, will play a crucial role in this ongoing exploration.