The number of satellite galaxies in the Milky Way, confirmed within a radius of about 1.4 million light years, is 61. The most famous? The Magellanic Clouds.
The last two satellite galaxies identified around ours, Sextans II and Virgo III, were discovered in 2024 by the National Astronomical Observatory of Japan. With these, the number of confirmed satellite galaxies within a radius of about 1.4 million light years is 61, including the two Magellanic Clouds, the best known.
More than double. According to the most recent high-resolution simulations conducted by the Institute for Computational Cosmology of the University of Durham (UK), however, there could be between 80 and 100 satellite galaxies still unobserved, which could be almost devoid of dark matter and therefore quite difficult to detect.
Galaxy? The lack of dark matter, in fact, causes stars to disperse, so that it is difficult to understand whether they form a galaxy or not. If they were identified, the total would rise to 140-160, approaching the simulations of the LCDM model (Lambda Cold Dark Matter, the standard cosmological model), which hypothesizes that our galaxy could have up to 200-300 small companions.
