This groundbreaking discovery was made in SPT0418-47, a galaxy obscured by dust, which has been in existence since the universe was only about 10% of its current age.
According to Sci-News, a research team led by GS Joaquin Vieira from the University of Illinois at Urbana-Champaign (USA) analyzed data from the James Webb Telescope, developed and operated by NASA. They found the presence of polycyclic aromatic hydrocarbons (PAHs) within the glowing dust particles of the galaxies at infrared wavelengths.
.jpg)
The SPT0418-47 galaxy appears red, with glowing organic molecules emitting a faint orange light, while a foreground galaxy is marked with a blue hue. (Image: NASA/ESA/CSA)
SPT0418-47 is located a staggering 12 billion light-years away from Earth, meaning that the light we see from it has taken 12 billion years to reach us. This implies that we are witnessing an image of this galaxy from 12 billion years ago, in the distant past of the universe.
Therefore, the PAHs it possesses – complex organic molecules that serve as the foundation of life as we know it today – are also the oldest organic molecules ever discovered by humankind.
Spectral data from the galaxy also reveals that the interstellar gas within it is enriched with heavy elements. This indicates that the galaxy has undergone a long and dynamic process, with multiple generations of stars being born and dying, as published in the scientific journal Nature.
The principle of cosmic evolution – starting with a few sparse elements and progressively creating more through stellar nucleosynthesis – is responsible for diversifying the chemical composition of the universe. When a star reaches the end of its life and undergoes a supernova explosion, it releases new elements, contributing to the ever-increasing diversity of the chemical makeup of the cosmos.
Thus, this research adds further evidence to the notion that the universe underwent rapid development during its early stages, a frontier that scientists have always sought to explore in order to unravel our own existence.
Furthermore, it introduces a novel method for investigating the past through dust particles surrounding galaxies, which have absorbed half of the radiation emitted by nearby stars throughout history and now shine brightly under the lens of infrared observatories.