The James Webb Space Telescope (JWST) has discovered over 1,000 mysterious galaxies resembling our Milky Way hidden in the early universe.
Recent research reveals that disk-shaped galaxies are ten times more common in the early universe than astronomers previously thought.
This intriguing discovery, along with other findings from JWST, points to a deeper mystery surrounding how large galaxies—and with them, the potential for life—first flourished in our universe. Researchers published their findings on September 22 in the Astrophysical Journal.
Disk-shaped galaxies like our Milky Way are much more common in the early universe than originally thought. (Image: Gabriel Pérez Díaz, SMM (IAC).
The lead author of the study, Leonardo Ferreira, an astronomer at Victoria University in Canada, stated: “For over 30 years, it has been believed that disk-shaped galaxies were very rare in the early universe due to the violent collisions that galaxies often undergo. The fact that JWST has found so many galaxies is another sign of this tool’s power and suggests that the structure of galaxies formed much earlier in the universe—indeed, much earlier than anyone had predicted.”
Galaxies Forming After the Birth of the Universe
Most theories about galaxy formation begin 1 to 2 billion years after the birth of the universe, by which time the earliest star clusters are believed to have transformed into dwarf galaxies. These dwarf galaxies then began to merge with one another, causing a series of violent galaxy mergers (after 10 billion years) that led to large galaxies like our own.
The Milky Way is a disk-shaped galaxy. With its spiral arms and flat sombrero shape, it is one of the most common types of galaxies in the universe today. However, in the early years of the universe—when the universe was denser and dwarf galaxies were abundant—astronomers have long assumed that galaxies resembling our Milky Way would quickly be distorted.
However, by using JWST to observe galaxies from 9 to 13 billion years ago, astronomers discovered that, among the 3,956 galaxies they identified, 1,672 were disk-shaped like our Milky Way. Many of these galaxies existed when the universe was just a few billion years old.
Co-author of the study, Christopher Conselice, a professor of extragalactic astronomy at the University of Manchester in the UK, remarked: “The new results from JWST push the timeline for the formation of Milky Way-like galaxies closer to the beginning of the universe. This suggests that most stars within these galaxies are changing our complete understanding of how galaxies form.”
He emphasized: “Based on these results, astronomers need to rethink our understanding of how the first galaxies formed and how galaxy evolution has occurred over the last 10 billion years.”
If this is true, it is very possible that life began in the universe much earlier than previously thought.
