07:15Adventures in ScienceSeries 2Episode 2: Supermassive Black HolesBBC Radio 4 Extra Duration: 15 minutes Sun 21st Apr 2013, 07:15 on BBC Radio 4 ExtraOnce the stuff of sci-fi, Ben Silburn explores the centre of the galaxy and the most spectacular objects in the universe.GenresFactualScience & NatureBrandAdventures in ScienceSeriesAdventures in Science: Series 2 Source: BBC Online