New Horizons and event horizons

In the latest episode of Radio Astronomy, the BBC Sky at Night Magazine team look at the recent Chinese lunar mission Chang’e 4, discuss the New Horizons flyby of Ultima Thule and wonder why a black hole isn’t as strong as a fridge magnet.

Plus, they speak to Martin Harwit, astrophysicist and author of Cosmic Discovery, about how some of the most important astronomical discoveries were made.