'Ghostly' Galaxies and the Mystery of Dark Matter

In 2018, using the Keck Observatory in Hawaiʻi, astronomers discovered the first known dark matter-deficient galaxy, DF2. It’s about the same size as the Milky Way, but way dimmer, with 200 times fewer stars. Since then, two more phantom galaxies (DF4 and DF9) have been spotted. All three of these strange galaxies exist along a line. Why? On this episode of The Quanta Podcast, host Samir Patel speaks with writer Robin George Andrews about this triplet of ‘ghostly’ galaxies and what they can tell us about the mystery of dark matter. This topic was covered in a recent story for Quanta Magazine. Each week on The Quanta Podcast, Quanta Magazine editor-in-chief Samir Patel and Senior Editor Hannah Waters speak with the people behind the award-winning publication to navigate through some of the most important and mind-expanding questions in science and math.