Astronomers have used the James Webb Space Telescope (JWST) to detect carbon in a galaxy from just 350 million years after the Big Bang - making it the earliest detection of any element in the universe other than hydrogen.
The very early universe was almost entirely made up of hydrogen, the simplest element, with small amounts of helium and tiny amounts of lithium.
All other elements we observe today were formed inside stars and circulated in their host galaxy when stars explode as supernovas seeding the next generation of stars.
With every new generation of stars and ‘stardust’, more metals - which, in astronomy, means elements heavier than hydrogen or helium - are formed. After billions of years, the universe evolved so it could support rocky planets like Earth and life.
Carbon is key as it can form into grains of dust that clump together, eventually forming into the first planetesimals and the earliest planets, and it is also key for the formation of life on Earth.
“Earlier research suggested that carbon started to form in large quantities relatively late – about one billion years after the Big Bang,” said co-author Professor Roberto Maiolino, from the Kavli Institute for Cosmology at the University of Cambridge. “But we’ve found that carbon formed much earlier – it might even be the oldest metal of all.”
The researchers used Webb’s Near Infrared Spectrograph (NIRSpec) to break down the light coming from the young galaxy into a spectrum of colours, since different elements leave different chemical fingerprints.
“These observations tell us that carbon can be enriched quickly in the early universe,” said lead author Dr Francesco D’Eugenio, also from the Kavli Institute. “And because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier – although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.”
The finding comes shortly after the announcement that astronomers, including at the Kavli Institute in Cambridge, had used JWST to find the two earliest and most distant galaxies yet confirmed, dating back to only 300 million years after the Big Bang.
