Exomoons that run away from their planets could become 'ploonets'

Despite a lot of searching, we haven’t found a moon around an exoplanet yet. According to a new study, that could be because these exomoons have been ejected from orbit around their home planet and turned into miniature planets called “ploonets”. Our own moon may even become a ploonet one day.

Mario Sucerquia at the University of Antioquia in Colombia and his colleagues modelled the interplay between exomoons and the giant planets they could orbit – gas worlds between 0.5 and 1.8 times the mass of Neptune.

We have observed these…