It goes without saying how exciting it was to see the first scientific images from the James Webb Space Telescope (JWST). But that was just the beginning, and though it’s only been a little over a week since then, JWST may have already discovered something unprecedented: It may have broken the record for the oldest known galaxy in the universe. Yes, you literally may have already seen when the first galaxies lit up.
It is a galaxy called GLASS-z13, and it dates back to only 300 million years after the Big Bang. That light had to travel a whopping 13.5 billion years to reach us! Also, because space is expanding, this galaxy must now be as far away as 33 billion light-years.
🚨 JWST has potentially broken records by detecting a galaxy that existed when the universe was only 300 million years old! The light from GLASS-z13 took 13.4 billion years to reach us, but the distance between us is now 33 billion light-years due to the expansion of the universe! pic.twitter.com/5AcOBwHuO1
— Dr. James O’Donoghue (@physicsJ) July 20, 2022
To turn down the heat on this exciting discovery a bit, we should note that this announcement comes after a group of scientists analyzed the JWST data. For now the research is available on a preprint site and until a peer-reviewed article is published in a journal, try to remain calm and skeptical.
We turn up the heat again – literally as the early Universe was quite hot – although we don’t know the exact age of GLASS-z13, it existed in the earliest era of the Universe and could have formed anytime within the first 300 million years. This means that it could be even a little older, although there are some details to review. It is potentially the oldest starlight ever seen!
The Universe began 13.8 billion years ago, when the Big Bang happened, for 400 thousand years afterwards everything was a cold and dark fog of hydrogen and helium atoms. After 400 million years the light had already been made, and the brightness was noticeable in the midst of the nascent galaxies. Somewhere in between, the first stars and also the first galaxies must have formed, it’s not known specifically when, so to find a galaxy in the first 300 million years is…really impressive.
It is unknown exactly when the first galaxies arose, until now the record for the oldest galaxy is held by the Hubble Space Telescope, it is called GN-z11 and dates back to 400 million years after the Big Bang. If the James Webb calculations are correct, it will break the record by 100 million years.
“The astronomical records are already crumbling and there are more that are reeling”, tweeted NASA’s chief scientist, Thomas Zurbuchen. Yes, I tend to only animate once the science results clear peer review. But this looks very promising!”
On the other hand, a few months ago astronomers announced the most distant galaxy candidate called HD1. Like the new galaxy detected by Webb, it is estimated to be 100 million light-years further away than the one Hubble discovered. JWST promises to see the first galaxies, in fact HD1 is one of their targets and will confirm their distance. What we are clear about is that we are going to have to get used to so many discoveries. Enjoy! there is a fascinating way to go….
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