The James Webb Space Telescope just made another huge discovery

Another major milestone in the quest to better understand our universe and the galaxies within it has been made by a team of international astronomers using new data from the James Webb Space Telescope. 

According to a press release from the European Space Agency, astronomers discovered what is now believed to be the four oldest known galaxies ever to be recorded.

IMAGE: NASA, ESA, CSA, M. Zamani (ESA/Webb)

Light from the galaxies has taken over 13.4 million years to reach Earth, which means their existence can be dated back to just 400 million years after the Big Bang. 

To put everything into perspective, the European Space Agency press release noted that these galaxies are so old that they existed at a time when our universe was only 2% of its current age, which is an astonishing discovery. 

Earlier evidence from the James Webb Space Telescope revealed several candidates for the universe’s oldest known galaxies, but nothing was definitive until recent spectroscopic observations provided proof according to the European Space Agency. 

“It was crucial to prove that these galaxies do, indeed, inhabit the early universe. It’s very possible for closer galaxies to masquerade as very distant galaxies,” explained Emma Curtis, an astronomer from the University of Hertfordshire. 

Photo by Nasa

“Seeing the spectrum revealed as we hoped, confirming these galaxies as being at the true edge of our view, some further away than Hubble could see! It is a tremendously exciting achievement for the mission.” Curtis added. 

IMAGE: NASA, ESA, CSA, M. Zamani (ESA/Webb), Leah Hustak (STScI)

The area of space in which the four galaxies were found has been known for over two decades according to Time Magazine’s Jefferey Kluger, however, astronomers have just never had the proper observational power to definitely find the older galaxies.

“Hubble studied the deep field for more than 20 years, but the telescope was always limited in what it could detect,” Kluger wrote. 

The Hubble Space Telescope viewed space primarily through the visible spectrum according to Kluger, and it was “effectively blind to infrared light.”

According to the Time Magazine journalist, infrared light is crucial for aiding in the discovery of older galaxies because of a complicated phenomenon known as redshift. 

“The farther an object in space is from us, the faster it is moving in the ever-expanding universe. That causes the wavelength of its light to stretch to the red end of the visible spectrum,” Kluger wrote. 

“Light from the most distant objects stretches even further, into the infrared—invisible to Hubble and us, but not to Webb,” the Time Magazine journalist added. 

According to NASA, the astronomers who discovered the older galaxies spent ten days observing nine different infrared colors to make their discovery using James Webb’s onboard Near-Infrared Camera and Near-Infrared Spectrograph.

Once an image was created, the astronomers discovered that they had actually collected light from 250 older galaxies, but took particular interest in four which they thought presented the best evidence for being the oldest known galaxies discovered. 

Photo by Nasa

“For the first time, we have discovered galaxies only 350 million years after the big bang, and we can be absolutely confident of their fantastic distances,” explained Brant Robertson, a member of the astronomer team from the University of Santa Cruz. 

“To find these early galaxies in such stunningly beautiful images is a special experience,” Robertson added. The data gathered from the new discovery will also help future astronomy teams hunting for older galaxies, and so the James Webb Space Telescope may be making another groundbreaking discovery.