Nasa's telescope detects complex molecules in galaxy 12 bn light-years away

Astronomers have discovered the universe's most distant organic molecules using the James Webb Space Telescope. It is the first time Webb has detected complex molecules in the far reaches of the universe.

The intricate molecules were found in a galaxy called SPT0418-47, located more than 12 billion light-years away.

The discovery sheds light on the relationship between chemical interactions in the universe's early galaxies and star formation.

The molecules, known as polycyclic aromatic hydrocarbons, can be found on Earth in the form of smoke, soot, smog, engine exhaust, and forest fires.

The base of organic molecules is carbon, considered to be one of the building blocks of life because it’s a key element in amino acids, which form proteins.

 

The findings were detailed in a study published in the journal 'Nature'.

The light from the dusty galaxy began travelling across the cosmos when the universe was less than 1.5 billion years old, or 10 per cent of its current age of 13.8 billion years. The galaxy was first spotted in 2013 by the National Science Foundation's South Pole Telescope.

Other observatories, including the Hubble Space Telescope and Chile's Atacama Large Millimeter/submillimeter Array, have observed it since.

However, the Webb telescope's infrared capabilities, which can see light invisible to the human eye and peer through cosmic dust, were able to capture new details about the galaxy. A phenomenon known as gravitational lensing also aided the space observatory.

“This magnification happens when two galaxies are almost perfectly aligned from the Earth’s point of view, and light from the background galaxy is warped and magnified by the foreground galaxy into a ring-like shape, known as an Einstein ring,” said study coauthor Joaquin Vieira, professor of astronomy and physics at the University of Illinois Urbana-Champaign, in a statement.

Albert Einstein's theory of relativity first predicted gravitational lensing.

“By combining Webb’s amazing capabilities with a natural ‘cosmic magnifying glass,’ we were able to see even more detail than we otherwise could,” said lead study author Justin Spilker, an assistant professor of physics and astronomy at Texas A&M University, in a statement.

“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,” said Spilker, who is also a member of Texas A&M’s George P and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy.

Investigating the early universe

Astronomers spotted the signature of the organic molecules after carefully analysing Webb's data. In space, molecules are abundant.

Here on earth, they are part of cancer-causing hydrocarbon emissions that contribute to the planet's atmospheric pollution.

Astronomers previously believed polycyclic aromatic hydrocarbons were a sign of star formation because they had observed the large molecules near bright young stars. However, Webb's data revealed that the presence of these molecules in the early universe may not have been an indicator of star birth.

“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,” Spilker said.

The unexpected discovery is assisting astronomers in piecing together answers to some of the universe's lingering questions.

“Discoveries like this are precisely what Webb was built to do: understand the earliest stages of the universe in new and exciting ways,” said study coauthor Kedar Phadke, a doctoral student of astronomy at the University of Illinois Urbana-Champaign, in a statement.

“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," he added.

The researchers further hope to use Webb's capabilities even more in the future as they search for even more distant galaxies.

(With agency input)