What is polarisation?
The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of a black hole, managed to show how it looks in polarised light. This is the first time astronomers have been able to measure polarisation, a signature of magnetic fields, this close to the edge of a black hole. The observations are key to explaining how the M87 galaxy, located 55 million light-years away, is able to launch energetic jets from its core.
But what is polarisation? And what does it have to do with black holes? These videos will explain what you see.