Hydrogen peroxide (HOOH) is one of the rare astromolecules that is widely known in the workaday human world. A report of its detection was announced in 2011 by Bergman et al. toward the ρ Oph cloud complex, specifically the A core. The observations were made with the APEX 12m telescope, a prototype of telescopes constructed for ALMA. A subsequent search for HOOH in a variety of other sources did not yield any further detections of the molecule.

Hydrogen peroxide is commonly used as a disinfectant and bleach. It is nonplanar, distorted away from the ideal combination of two 90° H–O–O bond angles and a 90° H–O–O–H torsion angle. The related compound HO₂, the hydroperoxyl radical, was discovered in 2012 toward the same source as HOOH by two of the authors of the HOOH detection, Parise and Bergman.