A Giant in Such a Young Universe: How Is It Possible?

Peering into the depths of space, the James Webb Space Telescope (JWST) has uncovered a galaxy so massive that it challenges current cosmological theories. Named ZF-UDS-7329, this galaxy contains more stars than the Milky Way and formed just 800 million years after the Big Bang, defying standard models that assume a necessity for dark matter in galaxy formation.


Researchers, having published their findings on February 14th in the journal Nature, are faced with a mystery. How can a galaxy reach such a mass without the influence of dark matter, an essential component according to the standard model of cosmology for the cohesion of nascent galaxies? This question is pushing scientists to reconsider our understanding of the formation of the first structures in the Universe.

The observation of ZF-UDS-7329 by the JWST has allowed us to look back 11.5 billion years into the past, revealing that the stars of this galaxy were formed about 13 billion years ago. This discovery raises questions about the timing and mechanism of the formation of the first galaxies. According to current theories, dark matter halos, combined with gases, would have played a crucial role in the creation of the first galaxies. However, the existence of ZF-UDS-7329, formed without enough dark matter, challenges this notion.

Researchers now face a challenge: understanding how these galaxies were formed so quickly. The discovery encourages the search for other similar galaxies, which could challenge preconceived ideas about galactic formation.