Cosmic QuestThe Imperfect CosmosBBC Radio 4 Extra Duration: 15 minutesFirst broadcast: Fri 6th Jun 2008, 15:45 on BBC Radio 4 FMLatest broadcast: Sat 18th Apr 2020, 02:15 on BBC Radio 4 ExtraAstronomer Heather Couper looks at Tycho Brahe's realisation that the heavens change - that a planet's orbit could be predicted.GenresFactualScience & NatureSeriesCosmic Quest Source: BBC Online