This artist’s impression illustrates a binary pair of giant stars. Despite being born from the same molecular cloud, astronomers often detect differences in binary stars’ chemical compositions and planetary systems. One star in this system is shown to host three small, rocky planets, while the other star hosts two gas giants. Using Gemini South’s GHOST, a team of astronomers have confirmed for the first time that these differences can be traced back to inhomogeneities in the primordial molecular cloud from which the stars were born.