A galaxy far, far away holds oldest oxygen ever seen

The spectroscopic signature of the most distant – and therefore oldest – oxygen atoms observed yet have been detected coming in a galaxy 13 billion light years away. Observed by the Alma radio telescopes in Chile’s Atacama desert, the spectral lines are evidence of the earliest star birth activity after the big bang.

Since oxygen is forged by fusion inside stars, it takes several generations of star births to generate enough of the element to make it detectable on Earth today. However, exactly when the first stars were born after the big bang more than 13.77 billion years ago has remained a matter of debate.