The trail has long escaped the astronomers were found in the stars in the constellation Orion.
"Oxygen gas discovered in the 1770s, but it took us more than 230 years to finally say with certainty that this very simple molecules exist in space," says Paul Goldsmith, Herschel project scientist at NASA's agency laboratory in California.
Astronomers say that the oxygen contained in the ice covering the surface of small dust grains, which releases water and oxygen when warm.
"This explains where some oxygen may be hiding," said Goldsmith.
"But we did not find it in large quantities, and still do not understand what is special about where we find it. The universe still keep many secrets."
NASA provides several technologies to support the science instruments on the Herschel telescope, launched in 2009. (*)