00:00 Start00:42 How big are black holes? 03:15 What coordinate system do astronomers use to map objects in space? 08:19 If Planet 9 is a black hole, how could we detect it? Subscribe Free: https://universetoday.com/newsletter๐Ÿš€ OTHER PODCASTS:โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•โ•Weekly Space Hangout: Weekly news roundup with Fraser, special guests, and other space journalists. RSS: https://www.universetoday.com/feed/wshaudio/iTunes: https://podcasts.apple.com/ca/podcast/weekly-space-hangout-audio/id836926769YouTube: https://www.youtube.com/channel/UC0-KklSGlCiJDwOPdR2EUcg/Astronomy Cast: Award-winning, long-running deep dive into space and astronomy with Fraser and Dr. Pamela Gay.