In this episode, friend of the show Geriant Lewis, Professor of Astrophysics at the Sydney Institute for Astronomy within the University of Sydney, joins us to unpack a fascinating New Scientist article theorising on how a strange line of dwarf galaxies may have formed.  We explore how high-speed collisions between dwarf galaxies can scatter gas and stars across space, sometimes giving rise to entirely new tidal galaxies. Geraint explains the latest thinking on where these dwarf galaxies come from and how these cosmic smash-ups might even shed light on one of the biggest mysteries in physics: the true nature of dark matter. www.geraintflewis.com/ Linkedin: Geriant Lewis Bluesky: cosmic_horizons