Is There Life in the Clouds of Venus?

S1 E3: For more than 100 years astronomers have seen dark patches swirling in the clouds of Venus, visible only in ultraviolet light. Could there be life-forms thriving in the balmy zone 50km above the hellish surface? On Earth, researchers find life everywhere they look, including acid-loving bacteria that could easily live in Venus' air. How will the experts investigate this fascinating possibility?