New research reveals that disk-shaped galaxies are more common in the early universe, over 10 times more prevalent than previously thought.
Disk-shaped galaxies like our Milky Way are much more common in the early universe than initially believed. (Image: Gabriel Pérez Díaz, SMM (IAC).)
This intriguing discovery, along with other findings from JWST, deepens the mystery surrounding the formation of large galaxies and the potential for life to bloom in our universe. Researchers announced their findings on September 22 in the Journal of Astrophysical Physics.
Lead author of the study, Leonardo Ferreira, an astronomer at the University of Victoria in Canada, stated, “For over 30 years, it was believed that these disk-shaped galaxies were very rare in the early universe due to the frequent intense collisions that galaxies underwent. The fact that JWST found so many galaxies is another sign of the power of this instrument and the structure of galaxies forming much earlier in the universe, much earlier than anyone predicted.”
Galaxies Forming After the Universe’s Birth
Most theories about galaxy formation begin about 1 to 2 billion years after the universe’s birth when the earliest star clusters were believed to have transformed into dwarf galaxies. These dwarf galaxies then started merging, resulting in a series of violent galaxy mergers (over 10 billion years) that led to large galaxies like our own.
The Milky Way is a disk-shaped galaxy with spiral arms and a flattened sombrero shape, making it one of the most common galaxy types in the universe today. However, in the early years of the universe, when it was more crowded, and dwarf galaxies were prevalent, astronomers long assumed that galaxies like ours would quickly become distorted.
However, by using JWST to observe from 9 to 13 billion years ago, astronomers have discovered that among the 3,956 galaxies they found, 1,672 are disk-shaped galaxies like ours. Many of these galaxies existed when the universe was only a few billion years old.
Co-author Christopher Conselice, a professor of extragalactic astronomy at the University of Manchester in the UK, stated, “The new results from JWST push back the formation time of galaxies like the Milky Way to near the universe’s beginning. This implies that most stars existed and formed in these galaxies, changing our complete understanding of how galaxies form.”
He emphasized, “Based on this result, astronomers have to rethink our understanding of the formation of the first galaxies and how galaxy evolution has occurred over the past 10 billion years.”
If this is the case, it’s very possible that life may have begun in the universe earlier than originally thought.