The cold, hard facts: Scientists redefine the chemical history of interstellar water in the early solar system

For the past 30 years, the significance of the anomalously low ortho-to-para ratios (OPRs) of gaseous water (H2O) in interstellar space has remained unknown. (In ortho hydrogen molecules, both nuclei spin in the same direction, while in para hydrogen the nuclei spin opposite directions.) Recently, …