New JWST images show surprisingly large galaxies in early cosmos

A series of new James Webb Space Telescope (JWST) observations show a population of candidate massive galaxies that formed up 500 million years after the Big Bang.

The images show off Webb's staggering capability for gazing into the ancient past of the universe with its state-of-the-art infrared instruments.

They also add to the growing number of galaxies observed by the $10 billion space observatory that are much larger than expected for such an early time in the universe.

New James Webb images alter our understanding of the cosmos

The new images, which are published today in a new paper in the journal Nature, shed new light on the formation of the very earliest galaxies.

"These galaxies are more massive than has been expected for this early point in time," a press statement reads. "Massive galaxies with stellar masses as high as 100 billion times that of the Sun have been identified at redshifts z ~ 6, approximately one billion years after the Big Bang, but it has been difficult to find massive galaxies at even earlier times," the statement continues.

Redshift is a measurement that denotes the "stretched" wavelength of light from the early universe towards the red part of the spectrum. This means that the redder an image, the more distant the object is from our solar system.

The researchers behind the new observations and study searched for massive galaxies in the first 750 million years after the Big Bang. To do so, they selected candidates at high redshifts that had been observed by James Webb.

The scientists identified six candidate massive galaxies with masses up to ten billion times that of our Sun, including one that they believe may have a stellar mass 100 billion times that of the Sun. This far exceeded the expected values. "If verified with spectroscopy, these findings provide evidence to suggest that galaxies grew massive quicker than expected early in the history of the Universe," the researchers wrote.

The new observations show that massive, complex galaxies, possibly capable of harboring life, existed much earlier in the universe's evolution than previously believed. It's a fascinating example of how James Webb is altering our understanding of our place in the cosmos.

More James Webb discoveries to come

James Webb launched on December 25, 2021, from Europe's Spaceport in French Guiana, but it started operating in a scientific capacity from Lagrange Point 2 on July 11.

The first Webb image revealed to the public showed a region of the night sky known as SMACS 0723. NASA explained at the time that it was the "deepest, sharpest infrared view of the universe to date," and it included galaxies that are more than 13 billion years old.

NASA expects that, if all goes to plan, Webb will be operational for roughly a decade, meaning it is sure to peer even further into the cosmos in the coming months and years.