Molecules of hydrogen peroxide have been found for the first time in interstellar space. The discovery gives clues about the chemical link between two molecules critical for life: water and oxygen. On Earth, hydrogen peroxide plays a key role in the chemistry of water and ozone in our planet’s atmosphere, and is familiar for its use as a disinfectant or to bleach hair blonde. Now it has been detected in space by astronomers using the ESO-operated APEX telescope in Chile..