The universe was much simpler at its dawn. That’s good news for researchers because it made the cosmos easier to compare with predictions from their models. To test their theories, scientists utilize the James Webb Space Telescope to delve deeper into the universe and further back in time to unravel the secrets of this cosmic evolution.
Astronomers are in for quite a surprise when it comes to the very first galaxies. In the latest study published on arXiv, a website for peer-reviewed scientific papers, a team of experts led by Jeyhan Kartaltepe (Rochester Institute of Technology) and David Finkelstein (University of California, Berkeley) reports finding that Webb has finally spotted these distant galaxies as they were at their very beginnings. This is the first time a telescope has done so.
To find the earliest galaxies, astronomers must peer into a patch of the sky that’s incredibly dark compared to our Milky Way. These galaxies have very little in common with our galaxy, however. This is because galaxies and other celestial objects move farther apart as the universe expands. Light from these objects then stretches like saltwater taffy, turning redder and redder as it gets further away. In astronomy, that redder hue is known as the galaxy’s “redshift,” the more it reddens, the older a galaxy appears.
Previous studies examining galaxies at high redshifts, such as those conducted by Hubble, found that the most distant ones looked more chaotic than the stable disk-shaped structures in present-day galaxies. But, as the universe ages and its galaxies mature, that chaos is expected to give way to orderly shapes that reflect violent mergers of these early galaxies. The new findings are consistent with that theory.
But these new results also reveal that, if our current understanding of the cosmos is correct, there shouldn’t have been enough ordinary matter around that early on to form all those bright and distant galaxies. This is because the standard model predicts that galaxies shouldn’t be able to grow this massive so quickly.
The discovery of these strange early galaxies could help astronomers solve how our galaxy and its companions formed. But more research will be needed to confirm this finding. Until then, astronomers are rejoicing at the possibility of finding answers to some long-held questions about how our universe began and evolved into the vast and complex structure it is today.