superimposed on their mirror image, are a key feature of biological life on Earth and have already been detected in other solar-system objects. Now, for the first time, a chiral molecule has been detected in interstellar space. Brett McGuire of the National Radio Astronomy Observatory in the US and colleagues used data from the Green Bank Telescope in West Virginia, with some help from the Parkes radio telescope in Australia, to detect propylene oxide near the centre of our Galaxy in the star-forming dust and gas cloud Sagittarius B2. The identification was made via multiple spectral lines, but the data did not allow the team to determine the molecule’s absolute handedness. The result should help in the ongoing struggle to understand the origin of the bimolecular chirality that is so important to life as we know it.