The European Space Agency’s Herschel telescope has found the first confirmed evidence of oxygen molecules in space, according to a report.

The traces, which have long eluded astronomers, were found in the star-forming region of the Orion constellation.

“Oxygen gas was discovered in the 1770s, but it’s taken us more than 230 years to finally say with certainty that this very simple molecule exists in space,” said Paul Goldsmith, Nasa’s Herschel project scientist at the agency’s Jet Propulsion Laboratory in California.

Astronomers say the oxygen is contained in ice that covers the surface of tiny dust granules, which release water and oxygen when warmed.

“This explains where some of the oxygen might be hiding,” said Goldsmith. “But we didn’t find large amounts of it, and still don’t understand what is so special about the spots where we find it. The universe still holds many secrets.”

Nasa provided some of the technology to support science instruments on the Herschel telescope, which was launched in 2009.