NASA's Webb Telescope Finds Two Galaxies From Near the Beginning of Time

"These observations just make your head explode," said one of the researchers who helped discover this ancient duo.

Monisha Ravisetti Former Science Writer
Monisha Ravisetti was a science writer at CNET. She covered climate change, space rockets, mathematical puzzles, dinosaur bones, black holes, supernovas, and sometimes, the drama of philosophical thought experiments. Previously, she was a science reporter with a startup publication called The Academic Times, and before that, was an immunology researcher at Weill Cornell Medical Center in New York. She graduated from New York University in 2018 with a B.A. in philosophy, physics and chemistry. When she's not at her desk, she's trying (and failing) to raise her online chess rating. Her favorite movies are Dunkirk and Marcel the Shell with Shoes On.
Monisha Ravisetti
4 min read
The dark background is space is speckled by a huge amount of galaxies.

Behind galaxy cluster Abell 2744, the bright spot labeled "1" is a realm that seems to have existed only 450 million years after the Big Bang. 

NASA, ESA, CSA, Tommaso Treu (UCLA); Image Processing: Zolt G. Levay (STScI)

Seeing NASA's James Webb Space Telescope in action is like watching the perfect film adaptation of a favorite novel. 

I vividly remember the prelaunch days, when its success was only theoretical. Almost every press release about the JWST was peppered with phrases asserting that the telescope would "unveil an unfiltered universe!" "pierce through curtains of dust!" and "take us where no other telescope can take us!" And for that to happen, scientists said, the machine would first achieve extraordinary feats like "traveling a million miles from Earth!" and "calibrating each of its gold-plated mirrors and never-before-used infrared sensors!"

It felt like a far-fetched dream -- but after liftoff, it soon became clear that the script of this movie would come directly from the pages of the book. Seamlessly, the JWST traveled a million miles from Earth, calibrated those priceless instruments, unveiled what you might call an unfiltered cosmos and pierced through curtains of interstellar noise to reveal brilliant baby stars and ancient, reddened galaxies. Again and again, it took us where no other telescope has taken us. And the end of the JWST drama doesn't appear to be in sight. 

On Thursday, NASA announced that the impressive invention found a pocket of galaxies in the distant universe, otherwise hidden to the rest of humankind's telescope army.

Two papers were published on the find this week in The Astrophysical Journal Letters, and according to the literature, there are two especially astounding galaxies sitting in the region. Just a small percentage of the Milky Way's size, these tiny realms are hypothesized to have existed approximately 350 million and 450 million years after the Big Bang (that's immensely close to the beginning of time). 

"We've nailed something that is incredibly fascinating," Garth Illingworth, professor emeritus of astronomy and astrophysics at UC Santa Cruz and co-author of one of the papers, said in a statement. "These galaxies would have to have started coming together maybe just 100 million years after the Big Bang. Nobody expected that the dark ages would have ended so early."

The dark background is space is speckled by a huge amount of galaxies.
Enlarge Image
The dark background is space is speckled by a huge amount of galaxies.

Two of the farthest galaxies seen to date are captured in these Webb Space Telescope pictures of the outer regions of galaxy cluster Abell 2744. The galaxies aren't inside the cluster, technically, but many billions of light-years farther behind it. Number 1 likely existed only 450 million years after the Big Bang, and number 2 existed 350 million years after the Big Bang. 

NASA, ESA, CSA, Tommaso Treu (UCLA); Image Processing: Zolt G. Levay (STScI)

Now JWST passes the baton to its creators

The initial find, per the team, took four days of analysis and involved two JWST research initiatives, called the Grism Lens-Amplified Survey from Space, or GLASS, and the Cosmic Evolution Early Release Science Survey, or CEERS. 

"The primal universe would have been just one hundredth its current age," Illingworth said of the era when these galaxies were born. "It's a sliver of time in the 13.8-billion-year-old evolving cosmos."

Plus, light emanating from the twinkling galaxies -- which is what the JWST caught -- suggests they're exceptionally bright, too.

"While the distances of these early sources still need to be confirmed with spectroscopy, their extreme brightnesses are a real puzzle, challenging our understanding of galaxy formation," Pascal Oesch, a researcher at the University of Geneva in Switzerland and second author of one of the papers, said in a statement.

Illingworth suggests that, perhaps, the galaxy duo is so luminescent because they once contained a great deal of low-mass stars -- though on the other hand, maybe they contain fewer, but super-duper bright and big, stars.

"Only Webb spectra will tell," Adriano Fontana, co-author of one of the studies and member of the GLASS-JWST team, said in a statement.

Against the background of space, lots of tiny spots represent giant galaxies across the universe. At the center is a scene of two merging galaxies, which looks like a swirls of pink, red and blue blurs. The JWST's iconic diffraction spikes are seen, too.

The JWST once caught this glimpse of a sparkly, sparkly cosmic scene hidden to the eyes of Hubble.

ESA/Webb, NASA, CSA, L. Armus, A. Evans

And if the distance aspect turns out to be true, one of the galaxies of interest, named GLASS-z12 -- the one thought to have lived 350 million years post-Big Bang -- might even be a record-breaker. The previous record holder for oldest (youngest?) galaxy ever is GN-z11, which existed 400 million years after the Big Bang and was identified in 2016 by Hubble and the Keck Observatory. 

"These observations just make your head explode," Paula Santini, co-author of one of the studies, said in a statement. "This is a whole new chapter in astronomy. It's like an archaeological dig, and suddenly you find a lost city or something you didn't know about. It's just staggering."

Another co-author of one of the studies, Erica Nelson of the University of Colorado, explained how she was struck by being able to measure the shapes of these galaxies too. "Their calm, orderly disks," she said, "question our understanding of how the first galaxies formed in the crowded, chaotic early universe." 

They'd have been nothing like the Milky Way galaxy, Andromeda and other giants we get to see in our universe as it is today.

What's up with the z's?

You might've noticed that galaxy names, including GLASS-z12 and GN-z11, are often laden with the letter "z" followed by a number. There's a reason for that. It's in reference to what's known as their redshift. 

Basically, redshift is what scientists use to determine how far away an object of interest is from our telescopes. The "red" bit comes from the fact that as objects move farther and farther away from Earth -- in tandem with the universe's expansion -- wavelengths of light they emit stretch out, becoming redder and redder. Really red things, and therefore things that are really far away, have higher z values. And vice versa for less-red things.

Here's an illustration showing what redshift basically does to the light coming from galaxies moving away from Earth.

NASA/JPL-Caltech//R. Hurt (Caltech-IPAC)

"With Webb, we were amazed to find the most distant starlight that anyone had ever seen, just days after Webb released its first data," said Rohan Naidu of the Harvard-Smithsonian Center for Astrophysics and lead author of one of the studies.

In August, Naidu also made headlines because of his discovery of what he called "Schrodinger's Galaxy Candidate." In short, this could be a galaxy with a staggering redshift value of z = 17. 

One day, studying such a realm could decode whether a bunch of crucial physics models stand the test of time, because we'd be analyzing the universe as it was so shortly after our clocks began. But, well, it's called "Schrodinger's galaxy candidate" because there's a lot of uncertainty about its true nature.