The Big Bang is generally accepted to have occurred roughly 13.7 billion years ago, a time when the universe contained light elements — the heaviest was hydrogen. From there, elements with significant heft permeated throughout the universe as we know it today.

But a shocking new study has found a cloud that shows no traces of any elements heavier than hydrogen, suggesting it may have been around at the time of the Big Bang.


"Everywhere we look, the gas in the universe is polluted by waste heavy elements from exploding stars," said Swinburne University of Technology PhD student Fred Robert in a statement. "But this particular cloud seems pristine, unpolluted by stars even 1.5 billion years after the Big Bang."

"If it has any heavy elements at all, it must be less than 1/10,000th of the proportion we see in our Sun," Robert continued. "This is extremely low; the most compelling explanation is that it's a true relic of the Big Bang."

The full study will be published in the scientific journal Monthly Notices of the Royal Astronomical Society, although a pre-print of the paper is available online here.

The first stars in the universe were created via hydrogen and helium. From there, other elements came from fusion reactions inside the stars, LiveScience reports, ultimately being flung out into space, touching everything — or in the case of LLS1723, nearly everything — in the universe. What makes LLS1723, known as a "fossil cloud," so special is that it is essentially uncontaminated from other elements and provides a look at the earliest minutes of the universe.

"We targeted quasars where previous researchers had only seen shadows from hydrogen and not from heavy elements in lower-quality spectra," Robert added. "This allowed us to discover such a rare fossil quickly with the precious time on Keck Observatory's twin telescopes."


Prior to the discovery of LLS1723, there were two other fossil clouds discovered, both in 2011.

"The first two were serendipitous discoveries, and we thought they were the tip of the iceberg," said John O'Meara, who discovered the other two and was a co-author on the study of LLS1723. "But no one has discovered anything similar — they are clearly very rare and difficult to see. It's fantastic to finally discover one systematically."

"It's now possible to survey for these fossil relics of the Big Bang," said Professor Michael Murphy at Swinburne University of Technology. "That will tell us exactly how rare they are and help us understand how some gas formed stars and galaxies in the early universe, and why some didn't."

Follow Chris Ciaccia on Twitter @Chris_Ciaccia