What’s the News: For the first time, astronomers have found molecular oxygen, which makes up about 20 percent of our air on Earth, in space. Using the large telescope aboard the Herschel Space Observatory, a team of researchers from the European Space Agency and NASA detected the simple molecule in a star-forming region of the Orion Nebula, located about 1,500 light-years from Earth. This takes astronomers one step closer to discovering where all of the oxygen in space is hiding.
What’s the Context:
- Oxygen is the third most abundant element in the universe, right behind hydrogen and helium. Astronomers see individual atoms of oxygen in space all the time, particularly around massive stars, and believe that molecular oxygen (O2) should be common, too. Scientists expect to see one molecule of O2 for every 100,000 molecules of H2, according to the European Space Agency.
- Astronomers hope that knowing the amount of O2 in molecular clouds will let them determine what role the molecule plays in cooling the clouds (thought to be an important step in star formation).
- But astronomers have searched in vain for decades, using balloons, ground-based telescopes, and telescopes in space, according to a release by NASA. In 2007, scientists using the Swedish Odin Telescope thought they had spotted the molecule, but other astronomers could not confirm the discovery.
How the Heck:
- With the Herschel telescope, the team analyzed the spectra of the Orion Nebula, hunting for the specific wavelengths of light that molecular oxygen produces. They had to use instruments in space because the Earth’s atmosphere absorbs most of the radiation at the relevant wavelengths.
- In a star-forming region of the nebula, the astronomers found about one molecule of O2 for every one million molecules of H2. The team suspects that oxygen is locked up in water ice that coats interstellar dust and that the O2 that they found may have formed after starlight heated the dust and released water, which then broke down into the detected oxygen molecules.
The Future Holds: The researchers are now going to inspect other star-forming regions, in hopes of finding more of the elusive molecule. “We didn’t find large amounts of [O2], and still don’t understand what is so special about the spots where we find it,” Paul Goldsmith, NASA’s Herschel project scientist, said in a prepared statement. “The universe still holds many secrets.”
Image courtesy of NASA/JPL