The Herschel Space Observatory has detected the first ever oxygen molecules in space, located in the Orion nebula, which ended a mystery lasting 230 years regarding oxygen in space.

Molecular oxygen, or two atoms of oxygen, was found in dense patches of gas and dust within the core of the Orion nebula by Herschel, headed by the European Space Agency (ESA). This star-forming region where the molecules of oxygen were found is one of the brightest nebulae visible to the naked eye, situated south of Orion's Belt.

This marks the first definite discovery of oxygen molecules in space, regardless of the fact oxygen is the third most abundant element present in the universe. Past attempts by the Swedish Odin telescope and NASA have spotted what could possibly have been molecules, but were never confirmed findings.

"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 lead author Paul Goldsmith, NASA's Herschel project researcher at the agency's Jet Propulsion Laboratory (JPL).

Oxygen stored in ice particles coating tiny dust grains, common in this region in space, are heated up when new stars form. As the icy grains are warmed, Goldsmith explains, water discharges, forming molecular oxygen in the dense gas clouds.

"This explains where some of the oxygen might be hiding," Goldsmith said.

Telescopes and HIFI far-infrared detectors were used at Herschel to find these molecules of oxygen. The astronomers use infrared technology to split light in the Orion nebula into submillimeter wavelengths. The spectra in the wavelengths showcase the individual fingerprints of molecules.

Astronomers have predicted they would find molecular oxygen in space, but far underestimated the amount upon the discovery, finding only one molecule of oxygen in Orion for every million, or so, hydrogen molecules.

"Theory suggests we should find lots of oxygen atoms locked in molecular oxygen, but previous searches kept falling short of such a large amount," Goldsmith said. "We didn't find large amounts of it."

Prompting a search for more oxygen molecules in other nebulae, the findings did end an extended mystery for astronomers.

Goldsmith said they "still don't understand what is so special about the spots where we find it. The universe still holds many secrets."

Hubbles sharpest view of the Orion Nebula, part of the Orion region
This dramatic image offers a peek inside a 'cavern' of dust and gas where thousands of stars are forming. The image, taken by the Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope, represents the sharpest view ever taken of this region, called the Orion Nebula. More than 3000 stars of various sizes appear in this image. Some of them have never been seen in visible light. The Orion Nebula is 1500 light-years away, the nearest star-forming region to Earth. Astronomers used 520 Hubble images, taken in five colours, to make this picture. They also added ground-based photos to fill out the nebula. The ACS mosaic covers approximately the apparent angular size of the full Moon. Thes observations were taken between 2004 and 2005. Hubble Space Telescope Orion T
Oxygen No Longer Lost in Space
Astronomers have at last identified the distinct signatures of oxygen molecules in space, using observations made with the Herschel Space Observatory, a European Space Agency mission with important NASA contributions. The rarity of cosmic oxygen molecules -- the same molecules making up part of the air we breathe on Earth -- is still a mystery, but the new observations provide clues about why they had gone missing. ESA/NASA/JPL-Caltech
Oxygen in Orion
This graphic illustrates where astronomers at last found oxygen molecules in space -- near the star-forming core of the Orion nebula. The molecules, whose presence had been hinted at in space before, were definitively confirmed using the Herschel Space Observatory, a European Space Agency mission with important NASA contributions. Herschel's heterodyne instrument for the far infrared, developed in part at NASA's Jet Propulsion Laboratory in Pasadena, Calif., was used to split light from a specific region of the Orion nebula apart into its different submillimeter wavelengths. Astronomers display this information in plots, called spectra, which reveal the fingerprints of molecules. In this case, they recognized three distinct fingerprints of oxygen molecules, as displayed in the spectrum pictured here. The three lines show different ranges of wavelengths, with the signatures of oxygen molecules highlighted in pink. ESA/NASA/JPL-Caltech
Digital Sky Survey image of the region around the Orion Nebula
Digital Sky Survey image of the region around the Orion Nebula NASA, ESA, M. Robberto (Space
NASA Water NASA Space