Forbidden Black Hole Merger and Chaos on Europa

We discuss the largest black hole merger observed to date, between two black holes that are in the so-called forbidden mass range. They must have been created by some ancient merger of other black holes themselves. It's black holes everywhere you look these days. Closer to home, we take a look at Europa's weird Chaos terrain and new insights on how Mars lost its atmosphere. We also get a shout out from Audrey's dog.