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The Rho Ophiuchi star formation region, about 400 light-years from Earth, contains very dense clouds of cosmic gas and dust. Hydrogen peroxide molecules were found in the area marked with the red circle. (S. Guisard/European Southern Observatory)

Hydrogen peroxide has been detected for the first time in interstellar space, offering hints about the origin of water, a similar molecule.

The chemical signature of hydrogen peroxide molecules, which consist of two oxygen atoms bookended by two hydrogen atoms, was detected in dense clouds of cosmic gas and dust in a distant part of our own galaxy, the Milky Way, reported the study published Wednesday in Astronomy & Astrophysics.

The light signals were captured by the European Southern Observatory's Atacama Pathfinder Experiment telescope (APEX) in the Chilean Andes.

But the chemical best known on Earth as an antiseptic, rocket fuel and bleach isn't likely to give interstellar tourists blond highlights in their hair, even if they somehow manage to make the 400 light-year journey from Earth.

"The amount of hydrogen peroxide in the cloud is just one molecule for every 10 billion hydrogen molecules, so the detection required very careful observations," said Per Bergman, lead author of the study, in a statement. Bergman is an astronomer at Onsala Space Observatory in Sweden.

The discovery is exciting for astronomers because water can be produced when hydrogen peroxide reacts with hydrogen under the right conditions. A lot of the water on Earth is believed to have originally formed in space, but scientists aren't sure how.

"We don't understand yet how some of the most important molecules here on Earth are made in space," said Berengere Parise, an astrochemist at the Max-Planck institute for Radio Astronomy in Germany who co-authored the paper. "But our discovery of hydrogen peroxide with APEX seems to be showing us that cosmic dust is the missing ingredient in the process."

The finding is consistent with previous studies that showed hydrogen peroxide doesn't form efficiently from hydrogen and oxygen gas, but proposed it could be formed on grains such as dust.

The clouds where the molecules were found are a region of the galaxy near the star Rho Ophiuchi. The area is a "stellar nursery" where new stars are formed. The clouds are made mostly of hydrogen, but contain traces of other molecules.