The remarkable James Webb Telescope has now offered mankind a possible glimpse of the farthest starlight from Earth anyone has ever seen, and a galaxy that was formed closer to the original Big Bang than any galaxy seen before.
Two galaxies billions of light-years farther behind the giant galaxy cluster Abell 2744 were discovered by the Webb. One is estimated as having come into existence 450 million years after the Big Bang — which has been estimated to have occurred 13.8 billion years ago — while the second, titled GLASS-z12, emerged only 350 million years after the explosion. Both galaxies are estimated to be tiny compared to the Milky Way galaxy of which Earth is a part.
“These observations just make your head explode. 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,” said Paola Santini, one the authors of a research paper led by Marco Castellano of the National Institute for Astrophysics in Rome, Italy.
Another research paper outlining the discovery was led by Rohan Naidu of the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology in Cambridge, Massachusetts. Both papers were published in the Astrophysical Journal Letters.
“With Webb, we were amazed to find the most distant starlight that anyone had ever seen, just days after Webb released its first data,” Naidu said of the second galaxy.
“Everything we see is new. Webb is showing us that there’s a very rich universe beyond what we imagined,” Tommaso Treu of the University of California at Los Angeles echoed. “Once again the universe has surprised us. These early galaxies are very unusual in many ways.”
The first galaxy reportedly has a redshift of 10.5 while GLASS-z12 has one of 12.5. Redshift and blueshift describe how a light wave moves, whether toward us or away from us. As a light is stretched, it is “shifted” toward the red end of the light spectrum. Thus the greater the redshift, the farther the light is from us.
GLASS-z12 is thus even farther away from us than the first galaxy found with it.
“At least three types of redshift occur in the universe — from the universe’s expansion, from the movement of galaxies relative to each other and from ‘ redshift,’ which happens when light is shifted due to the massive amount of matter inside of a galaxy,” Space.com explains.
Up until the discovery of GLASS-z12, the farthest known galaxy that was discovered was GN-z11, found in 2016 by the Hubble Space telescope; its redshift was 11.1.
“We’ve nailed something that is incredibly fascinating. These galaxies would have had 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,” Garth Illingworth a member of Naidu’s team, enthused. “The primal universe would have been just one hundredth its current age. It’s a sliver of time in the 13.8 billion-year-old evolving cosmos.”