T
elescopes are, in a way, time machines that allow us to glimpse faraway galaxies. Light moves faster than anything in the Universe. For instance, it takes light from the Sun about eight minutes to reach Earth, meaning the sunlight we feel on our faces is already eight minutes old. When astronomers use telescopes to observe galaxies, they see some that are nearby and others that are much farther away—some younger, some much older. In fact, astronomers have even observed galaxies that are millions or even billions of years old!
By studying the light from different galaxies, astronomers can piece together the history of the Universe and create a ‘cosmic timeline’ of how galaxies form. Until recently, they believed they had a good understanding of this timeline—but a new study is making them rethink some long-held assumptions.
Two different research teams studied the most distant (and therefore youngest) known galaxy, JADES-GS-z14-0. The light we see from this galaxy today began its journey a staggering 13.4 billion years ago—before our Solar System even existed! But when the researchers analysed their data, they found something surprising—something other young galaxies don’t have.
What was it? Oxygen.
That might not seem like a big deal—oxygen is everywhere around us—but in astronomy, certain elements appear only at specific stages of a galaxy’s life, much like how a driver’s license is only issued at a certain age.
Oxygen is produced in massive stars and spread into space through supernova explosions when those stars die. For oxygen to be present in JADES-GS-z14-0, the stars we’re seeing must be older than expected. Essentially, the researchers found a baby galaxy that had grown to the size of a teenager in a much shorter time than previously thought.
The discovery of this rapidly evolving galaxy raises more questions than answers about the early years of the Universe. Could galaxies have formed earlier than we assumed? Do they grow differently than we thought? How does this change our understanding of cosmic evolution? That’s the beauty of astronomy—it often leads to more amazing questions instead of easy answers. And the search continues.
Cool Fact
It isn’t just oxygen that’s made inside stars, their super-hot cores have created the calcium in our teeth, the sodium in our salt; and everything we can see, touch, and feel. That’s why stars are full of surprises… they make up everything!
(Space Scoop)
