‘Controversies and prospects’ examines the Rare Earth Hypothesis and looks at prospects for astrobiology and finding life elsewhere. The Rare Earth Hypothesis is that the fortuitous circumstances that have allowed complex life on the Earth are so uncommon that Earth might harbour the only intelligent life in the Milky Way. Opponents of this theory argue that our galaxy is unremarkable among many in the observable universe. With advances in technology, it's increasingly likely that major discoveries will be made in the coming decades. The discovery of Earth-sized exoplanets in habitable zones will ensure that the possibility of life elsewhere becomes more relevant than ever.