Evrim Yazgin
Cosmos science journalist
NASA’s James Webb Space Telescope (JWST) has spotted evidence of the most distant organic molecules to date, in a galaxy 12 billion light years away.
An international team of astronomers led by Texas A&M University associate professor Justin Spilker, published a paper on the discovery in Nature. The large organic molecules are the same ones found on Earth in smoke, soot and smog.
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Of course, the words “organic molecules” immediately imply life. But these discoveries are not evidence of life in the distant universe. In fact, long hydrocarbon chains are found throughout the cosmos.
Where there’s smoke there’s fire. Except when there isn’t.
Such intergalactic smoke signals have, in the past, been associated with star formation. But Webb’s discovery pours cold water on that idea.
“These big molecules are actually pretty common in space,” Spilker says. “Astronomers used to think they were a good sign that new stars were forming. Anywhere you saw these molecules, baby stars were also right there blazing away. Thanks to the high-definition images from Webb, we found a lot of regions with smoke but no star formation, and others with new stars forming but no smoke.”
The galaxy where the sooty organic molecules were found was first discovered in 2013 by the National Science Foundation’s South Pole Telescope. At 12 billion light years from Earth, the galaxy is a snapshot from just 1.5 billion years after the Big Bang – a little over 10 percent the current age of the universe.
“Discoveries like this are precisely what Webb was built to do: understand the earliest stages of the universe in new and exciting ways,” says co-author and University of Illinois Urbana-Champaign graduate student Kedar Phadke.
“It’s amazing that we can identify molecules billions of light-years away that we’re familiar with here on Earth, even if they show up in ways we don’t like, like smog and smoke. It’s also a powerful statement about the amazing capabilities of Webb that we’ve never had before.”
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But Webb was helped along the way by gravitational lensing – a phenomenon predicted by Einstein’s General Theory of Relativity.
Gravitational lensing occurs when a massive object, like a galaxy, bends the light from another object behind it, magnifying it and stretching it into a doughnut shape known as an “Einstein ring.”
“By combining Webb’s amazing capabilities with a natural ‘cosmic magnifying glass,’ we were able to see even more detail than we otherwise could,” Spilker notes. “That level of magnification is actually what made us interested in looking at this galaxy with Webb in the first place, because it really lets us see all the rich details of what makes up a galaxy in the early universe that we could never do otherwise.”